3D printing rocket engines

[guckyfan]

I understand rocket engines are usually made of copper because it can easily  be machined with the cooling channels and also has good heat conduction properties. However copper is not a very strong material and also not very heat resistant.

Making them of Inconel is very hard to do because the material cannot be machined in the same way. However assume that 3D printing advances enough to make printing large engines feasible. Would Inconel even be a suitable material? It is strong so it should be possible to make the combustion chamber and the regeneratively cooled part of the nozzle much lighter. At least that would be my uneducated guess.

But how would the material react to thermal cycles as the heat conduction capacity is much smaller? Thinner walls would only in a small part compensate for the lower conductivity. So what's your thought, would Inconel be a suitable material for large engines, especially if they are to be reusable and go through very many cycles?

I am thinking of the Raptor engine but it really is a general question.

Some guesswork figures. I have seen estimates the Raptor may have a weight of ~7 tons. Would 4 tons for combustion chamber and nozzle be right? There was mention of printers able to print 1kg/h. Assume that advancing technology makes 10kg feasible. That would give a time of 400 hours for printing one engine. That translates to ~20 engines per year. With high reusability from the beginning this may be enough so one or two printers could do the job.

There was also the price of 500$/kg Inconel powder. That would bring material cost to just 2 Million Dollars per engine but with that much demand prices may even drop.

[R7]

SuperDraco

[guckyfan]

SuperDraco

Yes, I am aware of that. But it is a very different size and very different task. I would not presume an Inclonel-Raptor will be an efficient design because SuperDraco is.

[R7]

F-1

The tubes comprising the thrust chamber were heavily jacketed at the combustion chamber and were reinforced by a series of bands around the nozzle. The thrust chamber's tubes were constructed of Inconel X-750, a high-temperature, heat-treatable, nickel base alloy. 178 primary tubes, hydraulically formed from 1-3/32 inch outside diameter Inconel-X tubing, made up the chamber body above the 3:1 expansion ratio plane (approximately 30 inches below the throat centerline plane). At this point, the tubes bifurcated, or split in two. Two one-inch-outside-diameter secondary tubes were spliced to each primary tube and formed the chamber from the 3:1 to the 10:1 expansion ratio plane.

Nothing wrong with Inconel as material for big engines. Challenge is to construct big enough 3D printer.

[go4mars]

Nothing wrong with Inconel as material for big engines. Challenge is to construct big enough 3D printer.

I read somewhere that EOS has one big enough to print aircraft wings in titanium or Inconel.

[docmordrid]

Nanfang Ventilator Co. of China has one that can print a diameter of 2.1 x 6.0 meters up to a mass of 300 tonnes. Mainly steels, including stainless, but it seems size is becoming less of a factor almost weekly.

[R7]

Cool. Is the surface quality of these big machines adequate for coolant channels and nozzle wall without post-processing?

Also are there machines that can print aluminium alloys? Lower melting point sure but way superior thermal conductivity and specific strength. Might cope with cryogenic coolants and/or something additional deposited on hot wall to reduce Al structure temperature.

[guckyfan]

Is the surface quality of these big machines adequate for coolant channels and nozzle wall without post-processing?

I think the surface quality correlates not with size but with printing speed. Maybe using several "print heads" parallel can help with speed instead of raw power of one print head. I imagine special printers can be designed for objects with mainly rotational symmetry. Let the print head or heads rotate plus radial linear instead of two linear movements. That should help with print quality. On a wide diameter several printheads fit. Going to the center less radial linear heads can be placed.

[guckyfan]

Also are there machines that can print aluminium alloys? Lower melting point sure but way superior thermal conductivity and specific strength. Might cope with cryogenic coolants and/or something additional deposited on hot wall to reduce Al structure temperature.

Since Aluminium can be machined as easily as copper I think it would already be used if it had advantages over copper.

[docmordrid]

The XCOR Lynx 5K18 engine has been used to test an aluminum nozzle. Co-developed with ULA as part of their joint projects.

http://xcor.com/press/2011/11-03-22_XCOR_and_ULA_demonstrate_rocket_engine_nozzle.html

[Prober]

F-1

The tubes comprising the thrust chamber were heavily jacketed at the combustion chamber and were reinforced by a series of bands around the nozzle. The thrust chamber's tubes were constructed of Inconel X-750, a high-temperature, heat-treatable, nickel base alloy. 178 primary tubes, hydraulically formed from 1-3/32 inch outside diameter Inconel-X tubing, made up the chamber body above the 3:1 expansion ratio plane (approximately 30 inches below the throat centerline plane). At this point, the tubes bifurcated, or split in two. Two one-inch-outside-diameter secondary tubes were spliced to each primary tube and formed the chamber from the 3:1 to the 10:1 expansion ratio plane.

Nothing wrong with Inconel as material for big engines. Challenge is to construct big enough 3D printer.

See how they re did the F-1 with some modern day toolsets.  http://forum.nasaspaceflight.com/index.php?topic=33141.msg1175892#msg1175892

[docmordrid]

Nothing wrong with Inconel as material for big engines. Challenge is to construct big enough 3D printer.

I read somewhere that EOS has one big enough to print aircraft wings in titanium or Inconel.

And SpaceX has an existing relationship with EOS - one of their printers is used to build SuperDraco.

I'd be shocked of they didn't try printing at least some Raptor parts.

[Prober]

Nothing wrong with Inconel as material for big engines. Challenge is to construct big enough 3D printer.

I read somewhere that EOS has one big enough to print aircraft wings in titanium or Inconel.

And SpaceX has an existing relationship with EOS - one of their printers is used to build SuperDraco.

I'd be shocked of they didn't try printing at least some Raptor parts.

I remember years ago some announcement of a new method to make titanium (outside or before 3D printing).

The claim what they could make Titanium out the door as cheap as steel.

[docmordrid]

And now Metalisys is making moves with 3D metal printer alloys.  If they're for real it'll be real interesting.

[sdsds]

http://www.businessweek.com/articles/2013-11-27/general-electric-turns-to-3d-printers-for-plane-parts

Each Leap engine will contain 19 metal 3D-printed fuel nozzles.

Not rockets, but "high-bypass turbofan" engineering is pretty close.

[Prober]

And now Metalisys is making moves with 3D metal printer alloys.  If they're for real it'll be real interesting.

they are for real.

 “The Metalysis process could reduce the price of titanium by as much as 75 per cent, making titanium almost as cheap as specialty steels. We believe that titanium made by the Metalysis process could replace the current use of aluminium and steel in many products. This world-first for a titanium 3D printed component brings us a step closer to making this a reality.” - See more at: http://www.themanufacturer.com/articles/metalysis-low-cost-titanium-powder-to-3d-print-automotive-parts/#sthash.vaw08xUO.dpuf


Believe a Ukraine Univ. also has something with Titanium.  btw: Ukraine & Titanium is a story more.

Another thought.......think of the Shuttle we could have had with more Titanium to work with at a low cost.

[baldusi]

I understand rocket engines are usually made of copper because it can easily  be machined with the cooling channels and also has good heat conduction properties. However copper is not a very strong material and also not very heat resistant.

AIUI, MCC are usually made out of Inconel, but have a copper lining applied on the inside. Combustion is not homogeneous, and the heat transfer characteristics of copper allow for heat to transfer to the colder parts and thus use more surface area. I think that I've also seen some regeneratively cooled MCC with the inner part, the one that has the channels milled, made out of copper, an the external part of some steel. Since the cooling channels are at higher pressure than the MCC interior, strength shouldn't be such an issue. And the channel walls work as copper radiators, which have excellent heat transfer characteristics.
Now, what would be extremely interesting is if you could 3D print with multiple metals. You could make the lining and add heat pipes. And I've always wondered about fiber wrapping the MCC and Nozzle with kevlar or such. But we're far from that technology yet.

[docmordrid]

Now, what would be extremely interesting is if you could 3D print with multiple metals. You could make the lining and add heat pipes. And I've always wondered about fiber wrapping the MCC and Nozzle with kevlar or such. But we're far from that technology yet.

You can use >1 material with some new devices, and Epson announced a few weeks ago a 5 year plan for a large scale  multi-material industrial printer for production. There was also talk of printing cars.

[TrevorMonty]

Now, what would be extremely interesting is if you could 3D print with multiple metals. You could make the lining and add heat pipes. And I've always wondered about fiber wrapping the MCC and Nozzle with kevlar or such. But we're far from that technology yet.

They do make a printer that can be used to blend 4 different metals. In the article Prober posted they were using it to create alloys, for testing their properties.

This printer may be able to do mix metals but there would be huge amount of wastage. All the unused metal powders would be mixed and couldn't be recycled.

[Adaptation]

This printer may be able to do mix metals but there would be huge amount of wastage. All the unused metal powders would be mixed and couldn't be recycled.

They could be separated.  Cyclone classifier should work well if they have different densities.  Magnetic separation could also work if some of the metals are magnetic and others aren't.  Depending on particle size you could also do froth flotation. 

To get a good quality of separation you'd probably want to sent it to someone who would specialize in it and 99.9999% (or whatever) purity may not be feasible. 

[docmordrid]

Some printers are using wires, akin to a MIG welder. Wire Feed Metal Deposition.

An outfit called Metalisys will make to-order alloy printing powders to size spec, and the unused portions should be reusable. Just about anything including titanium. Other companies are already providing inconel powders, which SpaceX is using to print the SuperDraco regen-cooled abort/landing thruster.

[R7]

Could ink-jet principle work with liquid metals, anyone trying that concept in 3d printing?

Many objects especially in rocketry are mostly axisymmetric and relatively thin walled, are any machines taking advantage of these properties to speed up the printing?

[baldusi]

Could ink-jet principle work with liquid metals, anyone trying that concept in 3d printing?

Those technologies only work on 2D. There are actually three technologies. Ink jet (HP), bubble jet (Canon) and magnetic loop (Epson). HP simply throws a drop of ink. Canon heats the ink until it actually explodes. And Epson has a continuous jet that it keeps deviating magnetically and recirculates it, when you need a drop they simply turn off the magnet that recirculates it. The only system that could work is the bubble jet, and the energy consumption would be huge. And even then, you'd need a 5axis print head and some way to measure what actually stuck so you can keep throwing material to your nominal form. I don't believe that such a print head and feedback complexity would be either cheap nor superior to current technologies. Plus, heat treatment is important for metals and making them liquid is not a good idea. Please note that sinthering uses very specific temperature right on the threshold.

Many objects especially in rocketry are mostly axisymmetric and relatively thin walled, are any machines taking advantage of these properties to speed up the printing?

Not that I know of. But such symmetry works very well for a lathe. But that's because you take material out. Adding isn't so easy while turning. Mainly because to take out you can make a point as thin as you need (your bit). But printing heads are big and wide. Or better, lathes take advantage of the concave solution, while for additive you have a convex one.

[Prober]

Could ink-jet principle work with liquid metals, anyone trying that concept in 3d printing?

Many objects especially in rocketry are mostly axisymmetric and relatively thin walled, are any machines taking advantage of these properties to speed up the printing?

that's why you should keep an eye on this thread and read the links. 
http://forum.nasaspaceflight.com/index.php?topic=33141.0

I've tried to add the new processes and new toolsets, they come out almost daily.

[JasonAW3]

With the exception of either a post or platform to start from, I think 3d printing of rocket engines in microgravity might be the most effecient way of building a rocket motor, bar none.differing layers of metals could be added and alloys that aren't possible in a 1 gravity environment could be mixed and used in ways that are difficult to imagine.
As an example; A rocket engine that utilizes a cooling system in a cermet bell nozzle could both improve the durability of the engine while reducing the overall mass required.  By making the Cermet in microgravity, you can control more precisely the layers of metal and ceramics for the best possible combination of materials.

[Prober]

Now, what would be extremely interesting is if you could 3D print with multiple metals. You could make the lining and add heat pipes. And I've always wondered about fiber wrapping the MCC and Nozzle with kevlar or such. But we're far from that technology yet.

You can use >1 material with some new devices, and Epson announced a few weeks ago a 5 year plan for a large scale  multi-material industrial printer for production. There was also talk of printing cars.

Printing cars or custom cars is being done.   Epson wishes to leapfrog with their printer to the market when ready.

[Prober]

I understand rocket engines are usually made of copper because it can easily  be machined with the cooling channels and also has good heat conduction properties. However copper is not a very strong material and also not very heat resistant.

Now, what would be extremely interesting is if you could 3D print with multiple metals.

The "Term" 3D Printing is misunderstood.   Dozens of new toolsets fall under the term 3D printing.

And I've always wondered about fiber wrapping the MCC and Nozzle with kevlar or such. But we're far from that technology yet.

What your talking about is composite materials.   The toolsets are available now from the high end to DIY home market because of the Reprap driving.

[baldusi]

I understand rocket engines are usually made of copper because it can easily  be machined with the cooling channels and also has good heat conduction properties. However copper is not a very strong material and also not very heat resistant.

Now, what would be extremely interesting is if you could 3D print with multiple metals.

The "Term" 3D Printing is misunderstood.   Dozens of new toolsets fall under the term 3D printing.

I know. I've used a 5 axis mill, a CNC lathe, a plasma pantograph and own a CNC micromill and I've used my brother's Makerbot. I understand the difference between SLS and EBS. What I'm thinking off is making embedded strengthening component of a different material. Imagine a turbine blade with an exterior of copper that has radiator inserts inside the blade, with an internal part made out of Inconel with Tungten reinforcements.

And I've always wondered about fiber wrapping the MCC and Nozzle with kevlar or such. But we're far from that technology yet.

What your talking about is composite materials.   The toolsets are available now from the high end to DIY home market because of the Reprap driving.

Of course that you could fibre wrap it with a CNC machine. I'm talking about an embedded fibre wrapping inside the solid. There's not current technology to mix fibres and metals.

[Prober]

I understand rocket engines are usually made of copper because it can easily  be machined with the cooling channels and also has good heat conduction properties. However copper is not a very strong material and also not very heat resistant.

Now, what would be extremely interesting is if you could 3D print with multiple metals.

The "Term" 3D Printing is misunderstood.   Dozens of new toolsets fall under the term 3D printing.

I know. I've used a 5 axis mill, a CNC lathe, a plasma pantograph and own a CNC micromill and I've used my brother's Makerbot. I understand the difference between SLS and EBS. What I'm thinking off is making embedded strengthening component of a different material. Imagine a turbine blade with an exterior of copper that has radiator inserts inside the blade, with an internal part made out of Inconel with Tungten reinforcements.

And I've always wondered about fiber wrapping the MCC and Nozzle with kevlar or such. But we're far from that technology yet.

What your talking about is composite materials.   The toolsets are available now from the high end to DIY home market because of the Reprap driving.

Of course that you could fibre wrap it with a CNC machine. I'm talking about an embedded fibre wrapping inside the solid. There's not current technology to mix fibres and metals.

A) One Auto firm has been in production for a couple of years making a new metal finished part. Comes out of two different alloys combined.

B) some old technology can do it, and some new ways can also mix it.

[Blackstar]

With the exception of either a post or platform to start from, I think 3d printing of rocket engines in microgravity might be the most effecient way of building a rocket motor, bar none.differing layers of metals could be added and alloys that aren't possible in a 1 gravity environment could be mixed and used in ways that are difficult to imagine.

You might want to look up the power requirements for metal additive manufacturing.

You might also think about how the technology might actually work (or not work) in microgravity.

[docmordrid]

With the exception of either a post or platform to start from, I think 3d printing of rocket engines in microgravity might be the most effecient way of building a rocket motor, bar none.differing layers of metals could be added and alloys that aren't possible in a 1 gravity environment could be mixed and used in ways that are difficult to imagine.

You might want to look up the power requirements for metal additive manufacturing.

You might also think about how the technology might actually work (or not work) in microgravity.

ESA seems to think it'll work on ISS,

http://www.esa.int/Our_Activities/Human_Spaceflight/Research/3D_printing_for_space_the_additive_revolution

and at the last Makers Faire there was a liquid metal jet deposition printer that only used 400w. Aluminum now, more later.

http://3dprintingindustry.com/2013/09/30/potential-home-metal-3d-printer-vader/

[bubbagret]

"Build Speed: 20 mL/h"
It takes about 20 drops (from a standard eye dropper) to make one mL

[sanman]

You might want to look up the power requirements for metal additive manufacturing.

You might also think about how the technology might actually work (or not work) in microgravity.

Depends on the method. You might find that electroplating or electroforming could achieve strong parts without the same high power requirements, because it's not using heat as the basis for mass deposition.

[baldusi]

I understand rocket engines are usually made of copper because it can easily  be machined with the cooling channels and also has good heat conduction properties. However copper is not a very strong material and also not very heat resistant.

Now, what would be extremely interesting is if you could 3D print with multiple metals.

The "Term" 3D Printing is misunderstood.   Dozens of new toolsets fall under the term 3D printing.

I know. I've used a 5 axis mill, a CNC lathe, a plasma pantograph and own a CNC micromill and I've used my brother's Makerbot. I understand the difference between SLS and EBS. What I'm thinking off is making embedded strengthening component of a different material. Imagine a turbine blade with an exterior of copper that has radiator inserts inside the blade, with an internal part made out of Inconel with Tungten reinforcements.

And I've always wondered about fiber wrapping the MCC and Nozzle with kevlar or such. But we're far from that technology yet.

What your talking about is composite materials.   The toolsets are available now from the high end to DIY home market because of the Reprap driving.

Of course that you could fibre wrap it with a CNC machine. I'm talking about an embedded fibre wrapping inside the solid. There's not current technology to mix fibres and metals.

A) One Auto firm has been in production for a couple of years making a new metal finished part. Comes out of two different alloys combined.

Can you tell me what part it is? Copper is extremely difficult for additive processes due to heat transfer properties, for example. And mixing two complementary solids is something I haven't heard of.

B) some old technology can do it, and some new ways can also mix it.

What sort of technologies are you referring to? Embedding fibers wrapping within a metallic solid is not something I've heard of. Of course things like glass reinforced acetal is common place. I'm talking more of something akin reinforced concrete. Where you have continuous fibers embedded with direction and continuity passing through specific parts of the solid for specific reinforcement.

[Adaptation]

Can you tell me what part it is? Copper is extremely difficult for additive processes due to heat transfer properties, for example. And mixing two complementary solids is something I haven't heard of.

You can plate them but this often has very poor bonding strength. 
You could possibly friction stir weld them. 

You could certainly arc spray (thermal spray) or supersonic cold spray it. 
These are additive processes and can be considered a rough printing method.  They have excellent bonding because the metals are embedded within oneanother, it can even create regions of traditionally impossible alloys.  A major drawback is that micro voids are impossible to prevent. 

You can codeposit physical vapors (two or more gaseous metals in a vacuum chamber simultaneously being deposited) this will also make non traditional alloys which will have good bonding.  But in order to get a good transition it will take a very long time.

If all else fails you can always explosively weld it. 

[R7]

Maybe one could make "Copper-Inconel" by depositing mixed copper-Inconel dust? Heat enough for Inconel particles to sinter, copper will melt briefly but remain locked in Inconel "sponge".

If above doesn't work the print porous Inconel piece and let molten copper seep in like in the making of Copper-Tungsten ?

and at the last Makers Faire there was a liquid metal jet deposition printer that only used 400w. Aluminum now, more later.

http://3dprintingindustry.com/2013/09/30/potential-home-metal-3d-printer-vader/

Just when I was asking for something like this... some day shops will have "Aluminium, Copper, Silver etc" cartridges next to Cyan, Magenta, Yellow and Black

[Prober]

With the exception of either a post or platform to start from, I think 3d printing of rocket engines in microgravity might be the most effecient way of building a rocket motor, bar none.differing layers of metals could be added and alloys that aren't possible in a 1 gravity environment could be mixed and used in ways that are difficult to imagine.

You might want to look up the power requirements for metal additive manufacturing.

You might also think about how the technology might actually work (or not work) in microgravity.

and at the last Makers Faire there was a liquid metal jet deposition printer that only used 400w. Aluminum now, more later.

http://3dprintingindustry.com/2013/09/30/potential-home-metal-3d-printer-vader/

Its an interesting technology but would have to pass many loops for use in microgravity.   

"The first step in the printer process sees an on-board cuboid electric furnace melt metal ingot for the extrusion material. A conventional 400-watt power supply powers the device – energy efficiency is not a problem here. The furnace is seen in the feature image as encased in a glossy-black cube."

Linkage for updates:  http://forum.nasaspaceflight.com/index.php?topic=33141.msg1181050#msg1181050

Edit: add link

[Blackstar]

With the exception of either a post or platform to start from, I think 3d printing of rocket engines in microgravity might be the most effecient way of building a rocket motor, bar none.differing layers of metals could be added and alloys that aren't possible in a 1 gravity environment could be mixed and used in ways that are difficult to imagine.

You might want to look up the power requirements for metal additive manufacturing.

You might also think about how the technology might actually work (or not work) in microgravity.

ESA seems to think it'll work on ISS,

http://www.esa.int/Our_Activities/Human_Spaceflight/Research/3D_printing_for_space_the_additive_revolution

and at the last Makers Faire there was a liquid metal jet deposition printer that only used 400w. Aluminum now, more later.

http://3dprintingindustry.com/2013/09/30/potential-home-metal-3d-printer-vader/

Dig a little deeper.

[catdlr]

a video of how 3D printing was used to create the engines for this acoustic testing of SLS.

NASA Using 3D Parts for Testing on Mini Model of World's Largest Rocket

Engineers at NASA's Marshall Space Flight Center in Huntsville, Ala., are using the latest technology -- 3D printing -- to make parts for a scale model of NASA's new rocket, the Space Launch System (SLS). The model is being used for acoustic testing, which will show how the powerful noise generated by the engines and boosters may affect the rocket and crew, especially during liftoff. The data will then be used to verify the design of the rocket's sound suppression system. (NASA/MSFC)

[JasonAW3]

It occurs to me that we seem to keep thinking about an inkjet type of 3d printing.

Another approach would be more of an extrusion method where a wire or bar of metal is heated in a vacuum to a nearly moltant level, then extruded onto a platform, (which is also used to start the cooling process) in a continiously layered pattern, building up the particular part that one is trying to print.  Using a nearly moltant metal, extruded like toothpaste in a vacuum allows the metal to not only adhear to itself, but to also do so without contamination.  As this is not being reduced to a vapor, or being used in a sintering technique, the energy costs should be far lower than most other 3d metal printing techniques.

[baldusi]

It occurs to me that we seem to keep thinking about an inkjet type of 3d printing.

Another approach would be more of an extrusion method where a wire or bar of metal is heated in a vacuum to a nearly moltant level, then extruded onto a platform, (which is also used to start the cooling process) in a continiously layered pattern, building up the particular part that one is trying to print.  Using a nearly moltant metal, extruded like toothpaste in a vacuum allows the metal to not only adhear to itself, but to also do so without contamination.  As this is not being reduced to a vapor, or being used in a sintering technique, the energy costs should be far lower than most other 3d metal printing techniques.

Heat transfer would be the critical issue. The cold plate would need some serious cooling loop. And the speed would be constrained by the cooling of the metal. And you'd need a very efficient airlock. Each vacuum cycling is pretty expensive, as I understand it. Both in actual gas and wear and tear.

[JasonAW3]

It occurs to me that we seem to keep thinking about an inkjet type of 3d printing.

Another approach would be more of an extrusion method where a wire or bar of metal is heated in a vacuum to a nearly moltant level, then extruded onto a platform, (which is also used to start the cooling process) in a continiously layered pattern, building up the particular part that one is trying to print.  Using a nearly moltant metal, extruded like toothpaste in a vacuum allows the metal to not only adhear to itself, but to also do so without contamination.  As this is not being reduced to a vapor, or being used in a sintering technique, the energy costs should be fa6r lower than most other 3d metal printing techniques.

Heat transfer would be the critical issue. The cold plate would need some serious cooling loop. And the speed would be constrained by the cooling of the metal. And you'd need a very efficient airlock. Each vacuum cycling is pretty expensive, as I understand it. Both in actual gas and wear and tear.

Well, you could put it trailing behind a plate outside of the ISS, to improve the vacuum and actually do the printing outside.

While we're not talking a perfect vacuum, it would be significantly better than any we could generate on Earth.

[docmordrid]

Although it's only using aluminum now (perhaps useful for the ORBITEC Vortex engine) Liquid Metal Jet Printing is pretty close to 3D extrusion, which BTW is already done with melted polymers.

Design News Blog post about LMJP....

[baldusi]

Interesting. Microgravity has the advantage on making cantilever features. But at the same time, on direct deposition methods, you sort of depend on gravity to keep it smoothly over a layer. And un even PLA surface is no problem to a 140C hot metallic print head. But metal to ceramics is a different matter. If you didn't left a smooth surface, once you try the next pass your head might interfere with excess material. And it's very difficult to assure flow will make a practically continuous surface.
Then you have the thermal issues. Air does carry heat away. Once in vacuum your only cooling methods are radiation, which is excruciatingly slow, or implementing a cold plate into the printer bed. In which case your cooling is a gradient in the z axis. What are the consequences for material deposition? I'm pretty sure a lot of thought will have to go into the G-Code regarding metal cooling, smoothing and plasticity.

[JasonAW3]

Interesting. Microgravity has the advantage on making cantilever features. But at the same time, on direct deposition methods, you sort of depend on gravity to keep it smoothly over a layer. And un even PLA surface is no problem to a 140C hot metallic print head. But metal to ceramics is a different matter. If you didn't left a smooth surface, once you try the next pass your head might interfere with excess material. And it's very difficult to assure flow will make a practically continuous surface.
Then you have the thermal issues. Air does carry heat away. Once in vacuum your only cooling methods are radiation, which is excruciatingly slow, or implementing a cold plate into the printer bed. In which case your cooling is a gradient in the z axis. What are the consequences for material deposition? I'm pretty sure a lot of thought will have to go into the G-Code regarding metal cooling, smoothing and plasticity.

The thermal issue is pretty simple as the base plate that the part is extruded to is also used as a coolant panel.  The heat would travel down (relative to the base plate) to the coolest part of the extrusion.  As the part will be in a near moltant state, outer smoothing should be pretty much as simple as having a smoothing tool traveling along behind the print head, spreading the metal into the groves created in the extrusion process.

It occurs to me that this COULD have the advantage of being able to first print the outside of a bell nozzle, allowing a web of cooling channels to be placed within the bell, and then, another print run could be done, sealing the cooling piping,(or fuel preheating piping, as you will) within the structure as an inner layer of metal is printed, bonded and smoothed to both the piping and outer bell, simultainiously.

This is an example of a potential multipass metal extrusion 3d print job that could, possibly, be done in orbit.

[baldusi]

You're forgetting to account for thermal expansion. Once you cool it contracts and stops being "stick" to the cool plate. And the contraction might curve the piece, separating the center of the plate, for example.

[JasonAW3]

You're forgetting to account for thermal expansion. Once you cool it contracts and stops being "stick" to the cool plate. And the contraction might curve the piece, separating the center of the plate, for example.

Not necessesarily.  The plate itself helps to control the cooling process allowing a regulated cooling process thus controlling heat differentials.  Attachment to the plate could be controlled by using a set of magnetic clamps that could hold the lower part of the item being fabricated against the plate.  The clamps would likewise be used to control heat flow to allow even cooling.parts that would need "quenching" as part of the initial heat treatment would require a specialized chamber into which the item would be placed, and the chamber would be partially flooded with whatever quenching solution is required.  As the solution would be sprayed directly onto and into the particular part, repressurization of the quenching chamber would not only not be required, but would in fact be inadvisable, as the solution would suddenly turn to vapor upon contact with the hot metal.  This would not only allow for the quenching process, but allow for the even dissipation of heat from the item.

[Robotbeat]

Nanfang Ventilator Co. of China has one that can print a diameter of 2.1 x 6.0 meters up to a mass of 300 tonnes. Mainly steels, including stainless, but it seems size is becoming less of a factor almost weekly.

That's not entirely accurate. The Nanfang machine is not a net-shape process, only NEAR-net shape. You still have to do a heck of a lot of post-process machining. Its only real advantages are you have a little less material wastage and a little less tool wear. It's no different than the electron beam free form fabrication that NASA Langley (which kind of pioneered the process) has been doing since at least 2000:


I mean, it has its uses, but it's nothing like the sort of 3d printing that, for instance, SpaceX is using for their SuperDracos (of course, SpaceX is merely using the process, not developing it). It can't do intricate parts (without extensive post-machining), just a basic blobby outline. However, you CAN do it in microgravity.

Still cool to watch, but the Chinese machine is by no means ground-breaking. Net-shape metal 3d printing is still incredibly limited in size (40cm cubed is the biggest machine that EOS has). But, of course, it's still useful.

All the net-shape metal 3d printers are pretty much from a bunch of German guys who used to be friends.

3d printing has a LOOOOOOOOOOOOTTTT of hype surrounding it. It is a very, very powerful tool, but a lot of the hype is kind of dumb. For instance, it will never compete in mass-production in the same way as traditional manufacturing. The per-part build time is several orders of magnitude greater. But for aerospace parts, that's just fine since you're doing relatively low-volume. And in a research environment, the technology is WAY faster than traditional manufacturing for making crude prototypes. Since you don't have to set up the tooling separately each time, you can go from idea in your head to part in your hands in an afternoon. For traditional manufacturing, that could take weeks. This allows you to iterate much, much faster with new ideas for designs. Time is very, very expensive, so in a research and development environment, this can make a HUGE difference.

Another thing: Generally, traditional type manufacturing can make you a part with much better material properties. Tolerances are way better, strength is higher, defects are lower, and stuff like surface finish and porosity is way lower for traditional manufacturing techniques. 3d printing is not usually a way to make a better, higher performance part, but to get a newly designed part made WAY faster and easier and with less fuss (and oftentimes, less red tape if you're at a place like NASA). Changes can be made very quickly, and you're generally less geometrically constrained than you are for traditional manufacturing.

[luinil]

For instance, it will never compete in mass-production in the same way as traditional manufacturing. The per-part build time is several orders of magnitude greater.

While I mostly agree with your post, in science and technology, never is a very very long time.

[Robotbeat]

For instance, it will never compete in mass-production in the same way as traditional manufacturing. The per-part build time is several orders of magnitude greater.

While I mostly agree with your post, in science and technology, never is a very very long time.

"In the same way" is also a cop-out. And granted, if you're talking 10^10000000 years or so, then yeah, maybe at that point.

But fundamentally, this statement is true. Tradition manufacturing set up in a factory line has unbeatable per-part speeds. I mean, you can have stamped parts flying out in just a few seconds while a good print of a functionally similar part would take hours. That's 3 and a half orders of magnitude different.

[KelvinZero]

Just wait until your 3D printers start printing more 3D printers out of moon dust.. Then when the moon is one big clanking replicator we will see who builds stuff faster.

[Robotbeat]

Living things are basically self replicators as you describe, but 9 women can't make a baby in 1 month.

[baldusi]

It's important to understand that Robobeat has correctly stated about single piece output per machine. Scalability, that's a whole different issue. Would 10,000 3D printers cost (acquisition and operation) than a big traditional factory? Today most certainly, in the future, probably on a case by cases basis.

[RDMM2081]

I just happened to run across this article describing a new class of 3d printed metamaterials being developed at MIT:
http://newsoffice.mit.edu/2014/new-ultrastiff-ultralight-material-developed-0619

It doesn't sound like the specific materials they are working with in this research would have any application in rocket engines, but it sounds like the process (projection microstereolithography) holds a lot of promise.  It's also a 3d printing process I'm not familiar with, does anyone know if it could be adapted to other materials which may be more applicable to rocket engines? (I.E. any metals)

[Prober]

It's important to understand that Robobeat has correctly stated about single piece output per machine. Scalability, that's a whole different issue. Would 10,000 3D printers cost (acquisition and operation) than a big traditional factory? Today most certainly, in the future, probably on a case by cases basis.

your talking about a "bot farm"

 http://forum.nasaspaceflight.com/index.php?topic=33141.msg1179912#msg1179912

Many firms have started this way (dirt cheap). 

Some firms use a finished printer to be sold to print out several parts for the next printer being built.  Many ways this is being done.

[guckyfan]

Living things are basically self replicators as you describe, but 9 women can't make a baby in 1 month.

Yes but a printer with 9 printheads may make a baby in 1 month instead of nine, depending on the geometry of the baby.

Say the baby has the shape of a rocket nozzle. 9 printheads can work at the diameter of the nozzle for most of the time until towards the top the available space cannot accomodate that number of printheads.

[KelvinZero]

And I thought I was getting hypothetical

[baldusi]

Current 3D printing methods for rocket parts use lasers and layers o nano particles. You'd need extra laser beams. But the limiting factor is more layer deposition than the sinthering part. While direct deposition is nice, it's the layers that actually allow you to do any form. With direct deposition you're limited to mostly concave when looked from below.

[JasonAW3]

Living things are basically self replicators as you describe, but 9 women can't make a baby in 1 month.

Yes but a printer with 9 printheads may make a baby in 1 month instead of nine, depending on the geometry of the baby.

Say the baby has the shape of a rocket nozzle. 9 printheads can work at the diameter of the nozzle for most of the time until towards the top the available space cannot accomodate that number of printheads.

I prefer to old fashioned way of making a baby myself.  More of a hands on operation anyway.

[john smith 19]

One of the scenarios in KE Drexlers "Engines of Creation" was construction of a rocket engine using nano assemblers.

The assemblers link together, construct "dumb" materials atom by atom then gradually "flush out" leaving honeycomb walls.

His point was that nanoassembly (like 3D printing) is additive, it excels at creating voids,  either holes or pockets inside structures.

Those FEA stress plots that show how you could lighten the structure (if you could afford the time to machine out the metal)? No problem. Don't deposit it in the first place.

I'd dispute that such systems have worse inclusions or porosity than conventionally cast or machined objects but I would say the actual crystalline quality may well be poorer. That may (or may not) be a problem.

IRL the question is more in the nature is the quality good enough to get the job done, be it prototype, or short production run (or F1 gear box gears, which were being laser depo'd in 2004).

[JasonAW3]

Do you think biological deposition could work as well as nanotech?  It occurs to me that there are a number of metal eating bacteria that, properly tweaked genetically, could be spread upon a basic form, and then start building up a metallic structure, much the same as coral deposits are formed.  Controlled growth could great some fairly complex forms, which could then be flushed out in much the same way as the lost wax technique of metal casting, except in this case, the mold IS the casting.

Such a technique should be a whole lot easier to produce than development of nanotech.

In retrospect, putting small asteroids in a warm, moist atmosphere and allowing an extractive variety of the Sam sort of bacteria could make mining of asteroids a WHOLE lot simpler.

[Asteroza]

Bionanotech sorta runs with that concept, using biologically based molecular engines and assemblers, for secreting stuff and working with certain "self assembling" types of composites. Synthetic organisms or tweaked existing organisms (particularly heat/metal tolerant extremophile bacteria) appear to be one path towards this, particular for surface coatings. For the cores of structural materials, the lack of fine control might be an issue though depending on the properties desired.

[JasonAW3]

Bionanotech sorta runs with that concept, using biologically based molecular engines and assemblers, for secreting stuff and working with certain "self assembling" types of composites. Synthetic organisms or tweaked existing organisms (particularly heat/metal tolerant extremophile bacteria) appear to be one path towards this, particular for surface coatings. For the cores of structural materials, the lack of fine control might be an issue though depending on the properties desired.

I think that this might be the superior method of 3d printing.  Spray on a bacterial coating to a base form, present a steady feedstock, (granulated or powdered metals) and allow the bacteria to build up the structure much like coral would.  In those areas where the build up is uneven, simply add more bacteria and feedstock.

[Prober]

My report on 3D printing in space will be out next month. It will discuss some of these issues.

Don't believe the hype. The hype is crazy. People who use and design these machines will tell you to not believe the hype.
Agrees 100%

As for increasing manufacturing speed, it can be done with a lot of caveats. Keep in mind that up to now, there has not been much effort to increase 3D printing speeds. But it could be done in certain ways for certain kinds of materials and parts. For instance, multiple print heads that are all on the same movement device. That way you could build up multiple versions at once. For some objects and with some materials, that may be a solution.

But 3D printing is never going to replace all aspects of production. It is likely to replace a few things in the overall process. But there are production processes that have been refined to very high degrees over many many decades, and 3D printing isn't going to leap ahead of them. It's a manufacturing technique, not magic. And in fact, for some things it is difficult to see how 3D printing could replace parts of the production process. For example, 3D printing just is not very high resolution, so for something like optics, where you want high precision, you're never going to get it out of a 3D printer.

I showed you the way on Optics its being done.   Nano 3D Printers are coming along, and a low cost version will be out sooner rather than later.  If you wish a review of your info let me know I'm game.

[Ronsmytheiii]

But fundamentally, this statement is true. Tradition manufacturing set up in a factory line has unbeatable per-part speeds. I mean, you can have stamped parts flying out in just a few seconds while a good print of a functionally similar part would take hours. That's 3 and a half orders of magnitude different.

Or you can use a 3D printer to create a cast for traditional casting, so the line between traditional manufacturing and 3D printing blurs.

[docmordrid]

http://www.3ders.org/articles/20140110-epson-to-launch-industrial-3d-printers-within-five-years.html

Jan.10, 2014

Epson is developing industrial, multi-material 3D printers, said president Minoru Usui recently when he attended Epson's 30th anniversary celebration in Sydney, Australia.

Usui said the company would be focused on developing 3D printers for commercial applications – such as in large-scale production environments – and not for consumers.
>
>
So what kind of printer is Epson working on? "We are developing our own printers, but our aim is to change everything. When it comes to 3D printing... we want our machines to make anything." Usui told Engadget at CES 2014. This "anything" could mean "cars" - Usui believes cars or its parts can be printed using additive manufacturing. It will take time to improve the technology and materials, but Usui expects Epson will launch its first industrial 3D printer within 5 years.

[TrevorMonty]

But fundamentally, this statement is true. Tradition manufacturing set up in a factory line has unbeatable per-part speeds. I mean, you can have stamped parts flying out in just a few seconds while a good print of a functionally similar part would take hours. That's 3 and a half orders of magnitude different.

Or you can use a 3D printer to create a cast for traditional casting, so the line between traditional manufacturing and 3D printing blurs.

Creating tooling for mass production is normally very expensive, this is one area 3D printing comes into it own. We had to spend $10,000 on the injection mould for a simply plastic item 10 years ago. If this can be reduced to $1-2,000 suddenly small production runs become viable.

[Prober]

But fundamentally, this statement is true. Tradition manufacturing set up in a factory line has unbeatable per-part speeds. I mean, you can have stamped parts flying out in just a few seconds while a good print of a functionally similar part would take hours. That's 3 and a half orders of magnitude different.

Or you can use a 3D printer to create a cast for traditional casting, so the line between traditional manufacturing and 3D printing blurs.

yes, recently saw a utube video where they automated the small parts casting.....it opened a lot of doors.

[Prober]

http://www.3ders.org/articles/20140110-epson-to-launch-industrial-3d-printers-within-five-years.html

Jan.10, 2014

Epson is developing industrial, multi-material 3D printers, said president Minoru Usui recently when he attended Epson's 30th anniversary celebration in Sydney, Australia.

Usui said the company would be focused on developing 3D printers for commercial applications – such as in large-scale production environments – and not for consumers.
>
>
So what kind of printer is Epson working on? "We are developing our own printers, but our aim is to change everything. When it comes to 3D printing... we want our machines to make anything." Usui told Engadget at CES 2014. This "anything" could mean "cars" - Usui believes cars or its parts can be printed using additive manufacturing. It will take time to improve the technology and materials, but Usui expects Epson will launch its first industrial 3D printer within 5 years.

Yeah, Epson is a great company and has many technologies that can be transferred over.   Many don't know that one of Epson's sister companies is Seko Epson that manufactures inexpensive assembly robots.   

The real amazing driver is the Reprap "open source" community.  As an example the Delta platform has been perfected for the most part now.   www.seemecnc.com (great guys).   Those deltas are dirt cheap and can be used for assembly.  Over a year ago a home grown chip shooter for pcb board assembly, was made out of a delta. It cost next to nothing to build.

[Scylla]

Aerojet Rocketdyne Awarded Large-Scale 3-D Printing Defense Contract to Develop Liquid Rocket Engine Applications
http://www.americaspace.com/?p=66087
http://www.rocket.com/article/aerojet-rocketdyne-awarded-defense-contract-large-scale-additive-manufacturing

SACRAMENTO, Calif., Aug 18, 2014 – Aerojet Rocketdyne, a GenCorp (NYSE: GY) company, was recently awarded a contract by Wright-Patterson Air Force Base through the Defense Production Act Title III Office for large-scale additive manufacturing development and demonstration. The contract will secure multiple large selective laser melting machines to develop liquid rocket engine applications for national security space launch services. Aerojet Rocketdyne and its subcontractors will design and develop larger scale parts to be converted from conventional manufacturing to additive manufacturing (3D printing).

[docmordrid]

http://www.nasaspaceflight.com/2014/08/spacex-dragon-iss-spacewalk-save/

L2 sources also note that parts for SpaceX’s next generation engine, the Raptor, are currently being 3D printed at the company’s Hawthorne base in California.

[Vultur]

Do you think biological deposition could work as well as nanotech?  It occurs to me that there are a number of metal eating bacteria that, properly tweaked genetically, could be spread upon a basic form, and then start building up a metallic structure, much the same as coral deposits are formed.

IIRC biological production of metal in metallic form (as opposed to metal ions in solution, which are ubiquitous, or metal-containing "rock" or minerals like calcium phosphate - in our bones , calcium carbonate -- in shells, iron sulfide -- which I believe some deep sea organism uses for plating/shells) is extremely rare.

There are some bacteria that produce tiny metal nanoparticles. There was some recent news about some wasps apparently having metal of some sort in their stings and/or ovipositors, but the things I've seen never quite come out and say that it's actually in metallic form, just that it contains metal (some even say 'ionized').

So I'm kind of skeptical of any vaguely near term use of biology to produce metal structures of significant size.

I think you could do quite a lot with biological manipulation of materials -- it deserves a lot of study, there's some interesting stuff like microbes that make inorganic nanotubes that are a semiconductor -- but this specific application seems like a stretch.

[docmordrid]

Some guys at Michigan State used Cupriavidus metallidurans to extract 24ct gold from gold chloride.

[Vultur]

Some guys at Michigan State used Cupriavidus metallidurans to extract 24ct gold from gold chloride.

Ah, OK, cool, I hadn't heard of that particular one.  I'd heard of Shewanella bacteria producing silver nanoparticles:
http://www.ncbi.nlm.nih.gov/pubmed/20509652

 These abstracts
http://www.ncbi.nlm.nih.gov/pubmed/23405956
http://www.ncbi.nlm.nih.gov/pubmed/19815503
say that Cupriavidus also produces nanoparticles (which can then aggregate into micrometer sized particles)

It's extremely interesting, yes... but it seems like it would take a huge amount of engineering to get something like a rocket engine out of this. It's probably hypothetically possible... there are plenty of complex inorganic/mineral structures produced by living things...  but it seems far off at best (and would it really be faster/better than other methods even if you could get it? Maybe if you wanted to do it with minimal-to-no infrastructure for some reason, just feed the minerals to a self-replicating living mass of the organism...)

[jongoff]

When I first started at Masten in 2004, we were working on a GOX/GH2 catalytic igniter, and were looking at doing a metal 3d printed part as a way to get the intimate mixing you need to make that type of system work. While I agree wholeheartedly that our change to just doing spark torch igniters was the right call, I almost wish we had gone through with it, because we probably could've claimed to be the first company using 3d printing for rocket engine parts... Oh well. :-)

~Jon

[docmordrid]

http://www.spacenews.com/article/launch-report/41626aerojet-rocketdyne-to-3-d-print-rocket-engine-parts-under-air-force-demo

Aerojet Rocketdyne To 3-D Print Rocket Engine Parts under Air Force Demo

WASHINGTON — Aerojet Rocketdyne will demonstrate the use of additive manufacturing techniques to produce selected, full-scale rocket engine components under a Defense Production Act (DPA) Title 3 contract awarded by the U.S. Air Force Research Laboratory, the company announced Aug. 20.
>

[TrevorMonty]

A 3D printed propulsion system for cubesats from Aerojet.

http://www.parabolicarc.com/2014/12/16/aerojet-completes-hot-fire-3d-printed-cubesat-propulsion-system/#more-54182

[A_M_Swallow]

A 3D printed propulsion system for cubesats from Aerojet.

http://www.parabolicarc.com/2014/12/16/aerojet-completes-hot-fire-3d-printed-cubesat-propulsion-system/#more-54182

It costs about $100,000 to launch a 1U cubesat.  It may be worthwhile Aerojet building its own cubesat to take the propulsion system to TRL 9.

[Prober]

Story from the 3D Printer section

Aerojet Rocketdyne Successfully Test Fires CubeSat Rocket with 3D Printed Piston       http://tinyurl.com/lbaa6sg

[cordwainer]

Makes me wonder how far away we are from 3D printing solid fuel rocket boosters for small payload launches?

[Stormbringer]

http://www.spacedaily.com/reports/Australia_researchers_create_world_first_3D-printed_jet_engines_999.html

printed jet engines.

[Asteroza]

http://www.spacedaily.com/reports/Australia_researchers_create_world_first_3D-printed_jet_engines_999.html

printed jet engines.

By appearances, it looks like they took apart an old jet turbine APU that Safran didn't mind being shown disassembled, 3D scanned the components, then 3D printed copies of the components in roughly appropriate materials. There is no mention of a full fit check or actual operation of the printed components fully assembled and running as an APU. Spinning turbine parts would likely need some final balance machining at the least, unless one has grossly high resolution 3D metal printers.

[john smith 19]

Note that although "3D printing" is fairly new you should keep in mind that additive techniques are at least half a century old.

Quite a lot of Aerojet designs used a combination of photoetched foils diffusion bonded into stacks.

The technology is also used by Velocisys and Meggit to build "printed circuit" heat exchangers and chemical reactors to deliver so called "process intensification."

Personally I always thought Aerojet could have pushed it much harder. They tended to do the stuff flat and then press (or use high pressure gas) to get it to shape.

Obvious extensions that came to mind were :-

Constructing parts as blocks but with either the final part inside the block, or internal cavities, defined by "perforations" around the outline. The little segments left holding parts inside the block would be quick to etch away, freeing the component.

Stretching or bending the unbonded foils should be much easier than doing it to the finished product, provided layer alignment can be preserved. It would mean that once the layers were bonded together they would need to have their edges trimmed to give the right size.

A technique in MEMS mfg is the use of "sacrificial" layers that can be preferentially etched to release objects.

Making structures that are curved as you go down the layers smoothly is probably too difficult. However by using a smaller number of masks could give a more viable "stepped" structure. Those steps should be preferentially etched, giving a (relatively) smooth result.

OTOH curves in the plane are relatively simple. Generally curves give smoother fluid flow.

It should be possible to fabricate in situ sensors based on fluids effects on the resonance frequencies of various structures, being driven and read by various acoustic transducers. Embedded electrical sensors are likely to more difficult due to the need to create insulating and encapsulating layers inside the structures.

By combining sub units split along different planes it would be possible to make more complex structures. this is relevant because of the difficulty of putting curves through layers.

Layer thickness can also be varied. Historically they have been foils the same thickness, but they could be substantially thicker, from a few 0.002" up to say 1 or 2 mm thick.

It should be possible to dispense with a photo resistant and go with a "direct write" exposure of the foils in a liquid, with the laser activating the liquid to etch the foil.

While these methods don't have the total flexibility of metal deposition of 3D printing they are likely to be much faster to produce a large unit quickly (or many small units as a block).

Just some possibilities which are also additive but not 3D printing.

[HMXHMX]

Note that although "3D printing" is fairly new you should keep in mind that additive techniques are at least half a century old.

Quite a lot of Aerojet designs used a combination of photoetched foils diffusion bonded into stacks.

The technology is also used by Velocisys and Meggit to build "printed circuit" heat exchangers and chemical reactors to deliver so called "process intensification."

Personally I always thought Aerojet could have pushed it much harder. They tended to do the stuff flat and then press (or use high pressure gas) to get it to shape.

Obvious extensions that came to mind were :-

Constructing parts as blocks but with either the final part inside the block, or internal cavities, defined by "perforations" around the outline. The little segments left holding parts inside the block would be quick to etch away, freeing the component.

Stretching or bending the unbonded foils should be much easier than doing it to the finished product, provided layer alignment can be preserved. It would mean that once the layers were bonded together they would need to have their edges trimmed to give the right size.

A technique in MEMS mfg is the use of "sacrificial" layers that can be preferentially etched to release objects.

Making structures that are curved as you go down the layers smoothly is probably too difficult. However by using a smaller number of masks could give a more viable "stepped" structure. Those steps should be preferentially etched, giving a (relatively) smooth result.

OTOH curves in the plane are relatively simple. Generally curves give smoother fluid flow.

It should be possible to fabricate in situ sensors based on fluids effects on the resonance frequencies of various structures, being driven and read by various acoustic transducers. Embedded electrical sensors are likely to more difficult due to the need to create insulating and encapsulating layers inside the structures.

By combining sub units split along different planes it would be possible to make more complex structures. this is relevant because of the difficulty of putting curves through layers.

Layer thickness can also be varied. Historically they have been foils the same thickness, but they could be substantially thicker, from a few 0.002" up to say 1 or 2 mm thick.

It should be possible to dispense with a photo resistant and go with a "direct write" exposure of the foils in a liquid, with the laser activating the liquid to etch the foil.

While these methods don't have the total flexibility of metal deposition of 3D printing they are likely to be much faster to produce a large unit quickly (or many small units as a block).

Just some possibilities which are also additive but not 3D printing.

I got the chance to try "platelet" fabrication technology in 1998-99 when we built this engine, which was LOX cooled, 2400 psia Pc design pressure, 6.6K-lbf.  As can be seen from the photos, individual copper foils were assembled in a stack and then diffusion bonded together.  It wasn't cheap at the time costing about $80K, but we fired it 40 times and it worked well.

Edit: spelling

[john smith 19]

I got the chance to try "platelet" fabrication technology in 1998-99 when we built this engine, which was LOX cooled, 2400 psia Pc design pressure, 6.6K-lbf.  As can be seen from the photos, individual copper foils where assembled in a stack and then diffusion bonded together.  It wasn't cheap at the time costing about $80K, but we fired it 40 times and it worked well.

Wow. 

That is a really nice piece of hardware. Beautiful surface finish.  Nice flame (are those shock diamonds?) . What was the fuel?

I'd seen references to a LOX cooled engine (was not sure it was pressure fed) but did not realize it was also a platelet and at such a high pressure (given the troubles of the SSME I'd guessed people would have preferred to keep the chamber pressure below say 1500 psi).

Just to be clear this is a LOX cooled engine in Copper. The common belief is such a thing would burn out at the slightest imperfection as the hot pure O2  hits the equally hot Copper.

Except it didn't.   

Am I right in thinking the stack was not inside a heated press but the pressure was applied by bolts? Putting the stack in a furnace and using the expansion differential between the bolts and the stack to generate the pressure?

The other question would be did this stack include the nozzle section or did this run nozzleless?

[HMXHMX]

I got the chance to try "platelet" fabrication technology in 1998-99 when we built this engine, which was LOX cooled, 2400 psia Pc design pressure, 6.6K-lbf.  As can be seen from the photos, individual copper foils where assembled in a stack and then diffusion bonded together.  It wasn't cheap at the time costing about $80K, but we fired it 40 times and it worked well.

Wow. 

That is a really nice piece of hardware. Beautiful surface finish.  Nice flame (are those shock diamonds?) . What was the fuel?

I'd seen references to a LOX cooled engine (was not sure it was pressure fed) but did not realize it was also a platelet and at such a high pressure (given the troubles of the SSME I'd guessed people would have preferred to keep the chamber pressure below say 1500 psi).

Just to be clear this is a LOX cooled engine in Copper. The common belief is such a thing would burn out at the slightest imperfection as the hot pure O2  hits the equally hot Copper.

Except it didn't.   

Am I right in thinking the stack was not inside a heated press but the pressure was applied by bolts? Putting the stack in a furnace and using the expansion differential between the bolts and the stack to generate the pressure?

The other question would be did this stack include the nozzle section or did this run nozzleless?

I don't want to take us too far off-topic, but the quick answers are:

The chamber was designed for 2400 psia at a 2.7:1 o/f mix ratio using LOX-Jet A, but I believe we never tested above about half pressure, though there was no indication it wouldn't have operated at full design pressure w/o incident.  I can't recall all the details.

The throat that was used wasn't flight-weight, and was transpiration-water-cooled.  Yes, those are shock diamonds.

I'm not conversant with all the manufacturing details, beyond knowing it was diffusion bonded, but I do believe the bolts provided the pressure under the expansion induced loading, as you suggest.

One side note about LOX cooling.  Much nonsense has been written about it.  Of course, GOX and hot metal don't mix.  But we inadvertently ran the "LOX-leak-into-the-chamber" experiment with this TCA.  The part was delivered with a hairline flaw – there was a microscopic failure to bond between two foils, about 1/3 of the way down the chamber and running maybe 5% of the circumference.  So LOX leaked out of that tiny gap and into the chamber.

Contrary to popular belief, not only didn't it catch on fire, there was absolutely no difference in the coloration or surface finish after dozens of firings.  The reason is obvious: the local o/f ratio goes significantly LOX "rich" at the crack, and thus the surface cools rather than heats.  Several years before NASA Lewis engineers saw the same thing when they deliberately induced flaws into a LOX-regen test article.

[john smith 19]

<chamber description removed for brevity>

Thank you, that was very interesting to me. Pressure feeding a 2400psi chamber for any significant length of time is going to need a very substantial test set up. Was the nozzle added after chamber fabrication? It's getting a smooth interior contour I'm having trouble with working it out. 

One side note about LOX cooling.  Much nonsense has been written about it.  Of course, GOX and hot metal don't mix.  But we inadvertently ran the "LOX-leak-into-the-chamber" experiment with this TCA.  The part was delivered with a hairline flaw – there was a microscopic failure to bond between two foils, about 1/3 of the way down the chamber and running maybe 5% of the circumference.  So LOX leaked out of that tiny gap and into the chamber.

Contrary to popular belief, not only didn't it catch on fire, there was absolutely no difference in the coloration or surface finish after dozens of firings.  The reason is obvious: the local o/f ratio goes significantly LOX "rich" at the crack, and thus the surface cools rather than heats.  Several years before NASA Lewis engineers saw the same thing when they deliberately induced flaws into a LOX-regen test article.

This really needs to be more widely known.

TBH I'd expected some signs of a leak but none at is even better. I'd also note that the results with NASA (which ran LH2/LO2) are even better, given the very wide combustion range of H₂

Something I've never understood about SpaceX is that if you're interested in engine reuse and avoiding coking issues logically you need to run on LOX for the coolant, but they don't, which seems odd.

[Prober]

I got the chance to try "platelet" fabrication technology in 1998-99 when we built this engine, which was LOX cooled, 2400 psia Pc design pressure, 6.6K-lbf.  As can be seen from the photos, individual copper foils where assembled in a stack and then diffusion bonded together.  It wasn't cheap at the time costing about $80K, but we fired it 40 times and it worked well.

Got to love it

Excellent examples of additive thinking.  This engine would translate perfect in todays environment. 

As is the design could be duplicated by laser cutting or plasma jet cutting.  Know many 17-21 year olds who have built lasers that could do the job.  One guy I know built a plasma cutter he has installed in his dad's garage.

Might take some effort but the design would also translate very well into additive printing methods, just about all methods.

HMX if sometime in the future you wish to have some real fun.  Put the design out there on a blog and let one of the colleges pick it up as a project.  Would be fascinating to see it further developed.

[Prober]

When I first started at Masten in 2004, we were working on a GOX/GH2 catalytic igniter, and were looking at doing a metal 3d printed part as a way to get the intimate mixing you need to make that type of system work. While I agree wholeheartedly that our change to just doing spark torch igniters was the right call, I almost wish we had gone through with it, because we probably could've claimed to be the first company using 3d printing for rocket engine parts... Oh well. :-)

~Jon

you might find this interesting

3D printed hot gas, film cooled thrusters.

 

[HMXHMX]

<chamber description removed for brevity>

Thank you, that was very interesting to me. Pressure feeding a 2400psi chamber for any significant length of time is going to need a very substantial test set up. Was the nozzle added after chamber fabrication? It's getting a smooth interior contour I'm having trouble with working it out. 

One side note about LOX cooling.  Much nonsense has been written about it.  Of course, GOX and hot metal don't mix.  But we inadvertently ran the "LOX-leak-into-the-chamber" experiment with this TCA.  The part was delivered with a hairline flaw – there was a microscopic failure to bond between two foils, about 1/3 of the way down the chamber and running maybe 5% of the circumference.  So LOX leaked out of that tiny gap and into the chamber.

Contrary to popular belief, not only didn't it catch on fire, there was absolutely no difference in the coloration or surface finish after dozens of firings.  The reason is obvious: the local o/f ratio goes significantly LOX "rich" at the crack, and thus the surface cools rather than heats.  Several years before NASA Lewis engineers saw the same thing when they deliberately induced flaws into a LOX-regen test article.

This really needs to be more widely known.

TBH I'd expected some signs of a leak but none at is even better. I'd also note that the results with NASA (which ran LH2/LO2) are even better, given the very wide combustion range of H₂

Something I've never understood about SpaceX is that if you're interested in engine reuse and avoiding coking issues logically you need to run on LOX for the coolant, but they don't, which seems odd.

Yes, the nozzle was added to the flight-weight chamber.  There was no particular problem with tolerances or seams.

[john smith 19]

Yes, the nozzle was added to the flight-weight chamber.  There was no particular problem with tolerances or seams.

Yes I suspected the nozzle would be added after the chamber was built. I didn't think tolerances would a problem as long as the foils did not slip relative to each other.

Thank you for that detailed description. While 3D printing (especially of metals) is quite new it's important to remember that "additive" mfg has a long history and includes both these platelet methods and "electroforming" (which has also been used to make TCA's in the past).

When I first started at Masten in 2004, we were working on a GOX/GH2 catalytic igniter, and were looking at doing a metal 3d printed part as a way to get the intimate mixing you need to make that type of system work. While I agree wholeheartedly that our change to just doing spark torch igniters was the right call, I almost wish we had gone through with it, because we probably could've claimed to be the first company using 3d printing for rocket engine parts... Oh well. :-)

Interestingly it was Aerojet (using platelets) that got this project to work in the first place, after an earlier attempt (IIRC without premixing before injection into the bed) produced poor results.

This was on the NTRS and was done sometime in the early 1970's.

[Prober]

NJ Engineer 3D Prints Entire Open Source Liquid Fueled Rocket Engine  http://3dprint.com/48179/3d-printed-rocket-engine/

"Sortino used a binary mixture of stainless steel and bronze to 3D print the engine components because of its hardness and high heat transfer. The total cost to have the parts 3D print was rather low. The 3D printed igniter ran Sortino $60, the injector $80, and the Engine $260, for a total of just $400 for the entire setup."

“While others (SpaceX/NASA) have 3D printed rocket engines recently, I’m pretty sure that I’m one of the first (or only) people to open source a rocket engine design,” explained Sortino. “A big reason for this is that there was traditionally a lot concern about releasing rocket engine information online due to ITAR requirements."

[john smith 19]

NJ Engineer 3D Prints Entire Open Source Liquid Fueled Rocket Engine  http://3dprint.com/48179/3d-printed-rocket-engine/

"Sortino used a binary mixture of stainless steel and bronze to 3D print the engine components because of its hardness and high heat transfer. The total cost to have the parts 3D print was rather low. The 3D printed igniter ran Sortino $60, the injector $80, and the Engine $260, for a total of just $400 for the entire setup."

“While others (SpaceX/NASA) have 3D printed rocket engines recently, I’m pretty sure that I’m one of the first (or only) people to open source a rocket engine design,” explained Sortino. “A big reason for this is that there was traditionally a lot concern about releasing rocket engine information online due to ITAR requirements."

keep in mind that (like HMX's package) this is also a pressure fed "Thrust chamber" Assembly"

Like HMX's TCA it's not clear that this unit had a nozzle (although in principle) that should be possible.

But for the price it's impressive.

This leaves the challenge of some kind of pump.

A couple of options exist for this. Doing a turbo pump is going to be very demanding. Probably easier to do individual blades and assemble afterward. SOP for gas turbines.

Option B is to do a positive displacement pump like John whiteheads team at Livermore, or the work at XCOR or flometrtrics. Flow metrics is (was, I'm not sure they are still around) the simplest, using a high pressure tank to pump low pressure fluids.

Whitehead believes a pump fed SSTO design small enough to put on the back of a pickup truck is possible. 

[Asteroza]

NJ Engineer 3D Prints Entire Open Source Liquid Fueled Rocket Engine  http://3dprint.com/48179/3d-printed-rocket-engine/

"Sortino used a binary mixture of stainless steel and bronze to 3D print the engine components because of its hardness and high heat transfer. The total cost to have the parts 3D print was rather low. The 3D printed igniter ran Sortino $60, the injector $80, and the Engine $260, for a total of just $400 for the entire setup."

“While others (SpaceX/NASA) have 3D printed rocket engines recently, I’m pretty sure that I’m one of the first (or only) people to open source a rocket engine design,” explained Sortino. “A big reason for this is that there was traditionally a lot concern about releasing rocket engine information online due to ITAR requirements."

I fail to see how opensourcing the design will absolve him of ITAR duties...

[Paul451]

Doing a turbo pump is going to be very demanding. Probably easier to do individual blades and assemble afterward. SOP for gas turbines

The trend for pumps and turbines is towards all-in-one printing. Specifically because 3d printing allows you to produce all the fiddly bits at the same time, drastically reducing time/labour in subsequent assembly.

Either directly sintered:


Or using 3d-printed sand-casting moulds:

[docmordrid]

More on impellers

http://www.calraminc.com/newsletters/Impeller_Paper.pdf

Discussion

This limited study of the electron-beam, layer-build process produced three impellers with all required drawing details. It also demonstrated that surface finishing techniques presently available are capable of producing finishes sufficiently smooth for operational use. Work planned for the coming year will include a detailed dimensional capabilities analysis; however, preliminary findings are favorable.  The mechanical properties results indicate that tensile and yield strengths are comparable to wrought product, such as forgings, while the ductility and toughness at cryogenic temperatures are superior. The very good ductility and notched toughness obtained are due undoubtedly to the very fine grain size resulting from the rapid solidification pattern of this particular process. Even without an oxygen content meeting that specified for ELI grade, the elongation and reduction in area values obtained at liquid hydrogen temperatures are over twice those typical for wrought Titanium-6Al-4V ELI and the notched-to-unnotched ratio is nearly equivalent to the more ductile, but less producible Titanium-5Al-2.5Sn ELI alloy. (Note that the minimum -253C notched tensile ratio for AMS 4930 Ti-6Al-4V ELI was 0.75 before this requirement was dropped from the latest versions of the specification). Although more work needs to be done, it would appear that the electron beam, layer-build process is viable for the production of complex hardware. The only limitation is one of size, as the working bed of present machines is a 12” diameter x 8” high.

Also,

http://www.esmats.eu/amspapers/pastpapers/pdfs/2014/merriam.pdf

[Prober]

Aerojet Rocketdyne Hot-Fire Tests Additive Manufactured Components for the AR1 Engine to Maintain 2019 Delivery   http://finance.yahoo.com/news/aerojet-rocketdyne-hot-fire-tests-130000241.html


Aerojet Rocketdyne Successfully Completes Hot-Fire Tests of 3D Printed Rocket Engine Injectors
 http://3dprint.com/51525/3d-printed-rocket-engine-injectors

A lot more info in this 2nd article including a video (not working atm)


Edit: add 2nd article

[john smith 19]

More on impellers

http://www.calraminc.com/newsletters/Impeller_Paper.pdf

This was a very interesting paper, showing both the (current) capabilities of the technology and the limitations.

Note that while the core materials being laid down certainly seem up to the job you need "post processing" to produce a finished part. 350 micro inches is about 8.9 micro metres, whereas machined blades (IIRC) run about 1/2 to 1/4 of that surface roughness, hence the need for "liquid honing" to polish the part. This is a nice process as it's fairly close to room temperature and pressure, as opposed to the highly specialized equipment for HIP.

An interesting idea (which I think has been done in plastic) is to switch to a finer grade of metal powder to give the surface finish. The downside is a more complicated feed mechanism.

I was quite surprised at size limit however. I'm sure I recalled someone printing Titanium like this in a chamber 19 feet long. 

 

[docmordrid]

http://www.mmsonline.com/blog/post/metal-additive-manufacturing-for-parts-up-to-7-feet-tall

>
One of the constraints on additive manufacturing machines that make metal parts from powder has been the relatively small build envelope of these machines. Rapid City, South Dakota-based RPM Innovations is now prepared to challenge that constraint with laser deposition additive manufacturing machines that have a build envelope of 5 ×5 ×7 feet. An 83-inch-tall rocket-like part made from Inconel 625 that was grown in one of this company’s machines will be on display in the Advanced Manufacturing Center at IMTS.
>
Nearly 80 percent of its applications have been related to aerospace or defense, including aircraft engine components and aircraft structural components for “companies whose names you’d recognize,” he says. Inconel 625, Inconel 718 and titanium 6-4 are among the alloys that the machines apply routinely.

The rocket-like part took around 340 hours to build is approximately 7,000 layers, he says. And to the RPM staff, that is not all that long. “We have had big parts—not as tall as this, but broader and a lot more complex—that took us 1,800 hours to build,” Mr. Mudge says.
>

[john smith 19]

http://www.mmsonline.com/blog/post/metal-additive-manufacturing-for-parts-up-to-7-feet-tall

>
One of the constraints on additive manufacturing machines that make metal parts from powder has been the relatively small build envelope of these machines. Rapid City, South Dakota-based RPM Innovations is now prepared to challenge that constraint with laser deposition additive manufacturing machines that have a build envelope of 5 ×5 ×7 feet. An 83-inch-tall rocket-like part made from Inconel 625 that was grown in one of this company’s machines will be on display in the Advanced Manufacturing Center at IMTS.
>
Nearly 80 percent of its applications have been related to aerospace or defense, including aircraft engine components and aircraft structural components for “companies whose names you’d recognize,” he says. Inconel 625, Inconel 718 and titanium 6-4 are among the alloys that the machines apply routinely.

The rocket-like part took around 340 hours to build is approximately 7,000 layers, he says. And to the RPM staff, that is not all that long. “We have had big parts—not as tall as this, but broader and a lot more complex—that took us 1,800 hours to build,” Mr. Mudge says.
>

That's impressive given these are high temperature Nickel based alloys but the one I'm thinking of is another electron beam in a vacuum system outfit.

Can't for the life of me think who they are. 

[Prober]

http://www.mmsonline.com/blog/post/metal-additive-manufacturing-for-parts-up-to-7-feet-tall

>
One of the constraints on additive manufacturing machines that make metal parts from powder has been the relatively small build envelope of these machines. Rapid City, South Dakota-based RPM Innovations is now prepared to challenge that constraint with laser deposition additive manufacturing machines that have a build envelope of 5 ×5 ×7 feet. An 83-inch-tall rocket-like part made from Inconel 625 that was grown in one of this company’s machines will be on display in the Advanced Manufacturing Center at IMTS.
>
Nearly 80 percent of its applications have been related to aerospace or defense, including aircraft engine components and aircraft structural components for “companies whose names you’d recognize,” he says. Inconel 625, Inconel 718 and titanium 6-4 are among the alloys that the machines apply routinely.

The rocket-like part took around 340 hours to build is approximately 7,000 layers, he says. And to the RPM staff, that is not all that long. “We have had big parts—not as tall as this, but broader and a lot more complex—that took us 1,800 hours to build,” Mr. Mudge says.
>

That's impressive given these are high temperature Nickel based alloys but the one I'm thinking of is another electron beam in a vacuum system outfit.

Can't for the life of me think who they are. 

does LM use it?

[docmordrid]

Well find out in May at AeroMat

https://asm.confex.com/asm/aero15/webprogram/Paper39823.html

Test program for adoption of Powder Bed Fusion EBM Ti-6Al-4V at Lockheed Martin Space Systems Co.

Tuesday, May 12, 2015: 11:00 AM
Room 201A (Long Beach Convention and Entertainment Center)
>

[john smith 19]

does LM use it?

I think they do.

[Prober]

might be some errors in this article, haven't sifted into all the details....Enjoy!

 Built Almost Entirely of 3D Printed Parts, the World’s First Battery-Powered Rocket is Unveiled

http://3dprint.com/58203/rocket-lab-electron-rutherford/

"The launch system, which is used to launch small satellites into orbit, features the electric Rutherford engine, which is the first oxygen/hydrocarbon engine to use 3D printing for all of its primary components, including everything from its engine chamber, to its pumps, main propellant valves, and injector."

[john smith 19]

might be some errors in this article, haven't sifted into all the details....Enjoy!

 Built Almost Entirely of 3D Printed Parts, the World’s First Battery-Powered Rocket is Unveiled

"The launch system, which is used to launch small satellites into orbit, features the electric Rutherford engine, which is the first oxygen/hydrocarbon engine to use 3D printing for all of its primary components, including everything from its engine chamber, to its pumps, main propellant valves, and injector."

I wonder how many people realize how radical this concept is.

They are saying that the total mass of batteries and motors is less than the total weight of propellant and gas generator.

This is a phenomenal  claim.

I wish them every success but realize this is very bold.

[R7]

I wonder how many people realize how radical this concept is.

They are saying that the total mass of batteries and motors is less than the total weight of propellant and gas generator.

This is a phenomenal  claim.

I wish them every success but realize this is very bold.

Must remember that GG propellant mass at the end of the ride is zero while depleted battery weighs the same as full.

Some W/kg and Wh/kg figures would be nice to go with that claim.

[ArbitraryConstant]

They are saying that the total mass of batteries and motors is less than the total weight of propellant and gas generator.

I'm gobsmacked too but the more I think about it the less trouble I have with it.

I'm not sure it's claimed to outperform gas generator. Rutherford is less thrust than Kestral. The alternative is probably pressure fed, and pressurized gas is even lower energy density than batteries and has other mass penalties.

Where the new electric pumping cycle lives in the trade space is probably closer to pressure fed and expander, not larger gas generator or staged combustion engines.

[TrevorMonty]

I don't how far these electric pumps would scale but for low cost small engines they seem ideal.

In theory they could dump spent batteries part way through the flight, would be way to go on 2nd stage as it needs to burn for a lot longer.

[john smith 19]

Must remember that GG propellant mass at the end of the ride is zero while depleted battery weighs the same as full.

Some W/kg and Wh/kg figures would be nice to go with that claim.

Good point.

[Prober]

This Is NASA's First 3D-Printed Full-Scale Copper Rocket Engine Part   http://gizmodo.com/this-is-nasas-first-3d-printed-full-scale-copper-rocket-1699394241

http://www.nasa.gov/marshall/news/nasa-3-D-prints-first-full-scale-copper-rocket-engine-part.html

[Asteroza]

As pointed out by others elsewhere, first full scale copper print is a great first step, but this particular print appears to have deformities, probably some slumping involved.

[john smith 19]

This Is NASA's First 3D-Printed Full-Scale Copper Rocket Engine Part   

A couple of points.

Glenn actually printed in a Copper alloy called GRo84. I can't recall if this is what the SSME combustion chamber was built from or was the next generation alloy they wanted to build the next gen SSME out of.

Historically those chambers were (IIRC) either forged or cast then the channels machined in to the outside but the channels were left open. Sealing them was done by wax filling them then electroforming a Nickel jacket around them. The chamber in the picture also has the close out done in GRo84, which should make it more resistant to issues around expansion mismatch between Nickel and Copper alloys.

IIRC the SSME chambers took something like 18-24 months to make.

One upgrade NASA looked at for SSME was to use wide channels for bulk of the chamber then as you got toward the hottest (throat) section splitting them into pairs. Depending on how and where you did this could save 50% of the turbopump power needed for this task. It would be interesting to see if this chamber incorporates this.

It may not be perfect but given its size a pretty good first effort.

I wonder if they will go the whole hog and hot fire it as well?

[AnalogMan]

This Is NASA's First 3D-Printed Full-Scale Copper Rocket Engine Part   

I wonder if they will go the whole hog and hot fire it as well?

From the linked article:

"The next step in this project is for Marshall engineers to ship the copper liner to NASA’s Langley Research Center in Hampton, Virginia, where an electron beam freedom fabrication facility will direct deposit a nickel super-alloy structural jacket onto the outside of the copper liner. Later this summer, the engine component will be hot-fire tested at Marshall to determine how the engine performs under extreme temperatures and pressures simulating the conditions inside the engine as it burns propellant during a rocket flight."

[mvpel]

I got the chance to try "platelet" fabrication technology in 1998-99 when we built this engine, which was LOX cooled, 2400 psia Pc design pressure, 6.6K-lbf.  As can be seen from the photos, individual copper foils were assembled in a stack and then diffusion bonded together.  It wasn't cheap at the time costing about $80K, but we fired it 40 times and it worked well.

Given my employer, and that I work in a building named after him, this immediately brings to mind the work of Raytheon's Percy L. Spencer, who devised the technique of brazing stamped copper plates together to build a multi-cavity microwave magnetron (patent #2458802), rather than machining it from a solid block of copper, in response to an urgent plea from Great Britain for help with air defense radars during WW-II. Additive manufacturing in 1940, in other words.

According to Raytheon: The First Sixty Years, the company bet the farm on this innovation and went on to dominate the radar market during the war to the tune of 80% share, producing up to an unprecedented 2,600 magnetrons a day.

[john smith 19]

Given my employer, and that I work in a building named after him, this immediately brings to mind the work of Raytheon's Percy L. Spencer, who devised the technique of brazing stamped copper plates together to build a multi-cavity microwave magnetron (patent #2458802), rather than machining it from a solid block of copper, in response to an urgent plea from Great Britain for help with air defense radars during WW-II. Additive manufacturing in 1940, in other words.

Correct. People sometimes underestimate how well developed some techniques are because they are only used in quite niche applications. Diffusion bonding of Aluminum is a routine process, but only in some parts of the automotive radiator business, for example.

According to Raytheon: The First Sixty Years, the company bet the farm on this innovation and went on to dominate the radar market during the war to the tune of 80% share, producing up to an unprecedented 2,600 magnetrons a day.

Note 1 key difference between this approach and others.

Brazing implies a separate layer of lower melting point alloy (the braze) between the shims. Sectioning the finished article would therefor show distinct bond lines between them.

However things like Diffusion bonding and (molten drop based) 3d printing won't have this. This means the structure can operate to the full temperature range of the parent alloys, not the braze layer. . Not important to the Magnetron application. Might be in others. YMMV

[Prober]

Students to Make History with 3D Printed Rocket Engine   http://tinyurl.com/o5bvhpt

"Late in 2013, Students for the Exploration and Development of Space (SEDS) at UCSD grabbed headlines by hot-fire testing a 3D printed rocket. Mentored and assisted by faculty at UCSD and advisers at NASA, the students designed the Tri-D rocket in just eight months and developed with only $6,800."

"They 3D printed the 8-in diameter engine using direct metal laser sintering of Iconel 718 (a nickel chromium alloy) with help from GPI Prototype Inc and NASA, and successfully hot fire tested it in the Mojave Desert in California. "

[Stormbringer]

I read something in an article on the upcoming SpaceX manned dragon launch abort system test that the lift vehicle in the test will have 3D printed rocket engines.

http://phys.org/news/2015-05-spacex-mile-high-feature-buster-dummy.html

Called SuperDracos, the engines were made from 3-D printing. It will be the first time that SpaceX fires all eight of them at the same time.

[john smith 19]

I read something in an article on the upcoming SpaceX manned dragon launch abort system test that the lift vehicle in the test will have 3D printed rocket engines.

http://phys.org/news/2015-05-spacex-mile-high-feature-buster-dummy.html

Yes. It's somewhat old news. Musk mentioned it during the unveiling of the Dragon 2.0 capsule. Interestingly he said they didn't start by looking at this technology. They were having trouble getting the conventional approaches to work and someone suggested it.

[TrevorMonty]

http://www.esa.int/Our_Activities/Space_Engineering_Technology/Hot_firing_of_world_s_first_3D-printed_platinum_thruster_chamber

[TrevorMonty]

Blue Origin New Shepard has 400 3d printed parts in it.  From tweet the just posted.
I guessing these parts cover both LV and engine.

[Prober]

http://www.esa.int/Our_Activities/Space_Engineering_Technology/Hot_firing_of_world_s_first_3D-printed_platinum_thruster_chamber

Stories in the 3D materials as well
http://3dprint.com/73961/esa-3d-printed-thruster/

[john smith 19]

Stories in the 3D materials as well
http://3dprint.com/73961/esa-3d-printed-thruster/

Note while a Platinum alloy sounds expensive Iridium is in the same class.

OTOH the fairly small number of units a year they are talking about suggests they could savemoney as laser deposition is basically a near net shape mfg process.

[john smith 19]

Reaction Engines have also been using 3D printing

News update on the website: Rocket Testing Underway

- PRESS RELEASE -

Monday 15 June 2015

Reaction Engines Ltd. have begun their latest round of rocket engine testing in Westcott, UK.

The SABRE engine requires a novel design of the rocket engine’s thrust chamber and nozzle to allow operation in both air-breathing and rocket modes, as well as a smooth transition between the two. The Advanced Nozzle project is demonstrating the feasibility of this concept and represents a significant technology development effort towards the SABRE demonstrator engine.

The test engine, which has been successfully fired 15 times during its initial commissioning phase in spring 2015, incorporates several new technologies including a 3D printed, actively cooled propellant injector system. Aerodynamic data collected from the firings is being used to validate in-house computational modelling and advance the nozzle design. The test campaign is being operated by Airborne Engineering Ltd in Westcott, Buckinghamshire. Operations are planned to continue throughout 2015, including long duration burns and tests investigating the transition between air- breathing and rocket operation planned for later in the year.
[/quote]

I think that makes it the first air/H2/O2 thrust chamber to be tested anywhere.

While I think this could have been CNC made I suspect 3DP let them tweak the injector design faster and cheaper, although I doubt the whole TC was made this way.

If successful this will give proof a single design can burn air and O2 with H2 and switch between the two during a test run long enough to simulate the full ground-to-space trajectory.

O2/H2 also runs hotter than O2/RP1, so it's a significant feat in terms of temperature.

[Prober]

NASA & Aerojet Rocketdyne Use 3D Printing to Expedite Independence from Russia

http://tinyurl.com/pdx9k7k

"Julie Van Kleeck, Aerojet Rocketdyne vice president of Advanced Space & Launch says, “This is another example of Aerojet Rocketdyne’s focus to maintain schedule for the United States to be able to have AR1 ready to fly in 2019, to keep our country on track to end dependence on Russian engines.”"

[Prober]

3D Printed Guided Missiles are Now a Reality Thanks to Raytheon

http://3dprint.com/81850/3d-printed-guided-missiles/

"Raytheon has been using and experimenting with the technology for years now, especially in the prototyping process. Now, however, the company says that they have 3D printed just about every component needed for a guided weapon. This includes the 3D printing of the rocket engines, the parts for the guidance and control systems, the fins on the missiles themselves, and more."

[docmordrid]

From a 3D printed .45 automatic to guided missiles in <2 years. PROGRESS!!

/s

[Prober]

The 3D Printed story (article) of this:
http://forum.nasaspaceflight.com/index.php?topic=33141.msg1419875#msg1419875

NASA Conducts Successful Tests on New 3D Printed Turbopump for Rocket Engines
http://3dprint.com/92121/nasa-3d-print-turbopump/

“is a propellant pump with two main components: a rotodynamic pump and a driving gas turbine, usually both mounted on the same shaft, or sometimes geared together. The purpose of a turbopump is to produce a high pressure fluid for feeding a combustion chamber or other use.”

Now, this isn’t the kind of thing you can just casually toss off the block and hope that it works. Its creation took a total of two years, but if that seems like a lot, without the availability of 3D printing, it is estimated that it would have taken at least four. So, if you’re doing the math, that’s 55% fewer parts in 50% of the time…and that’s a pretty big improvement.

[ArbitraryConstant]

Now, this isn’t the kind of thing you can just casually toss off the block and hope that it works. Its creation took a total of two years, but if that seems like a lot, without the availability of 3D printing, it is estimated that it would have taken at least four. So, if you’re doing the math, that’s 55% fewer parts in 50% of the time…and that’s a pretty big improvement.

We've heard in the past about impact of build/test/modify cycles, it's hard to imagine how printing could fail to accelerate that.

[Prober]

NASA Successfully Tests 3D Printed F-1 Rocket Engine Component
http://3dprint.com/95914/nasa-3d-print-f1-rocket-engine/

“This test gave NASA the rare opportunity to test a 3D-printed rocket engine part, an engine part for which we have lots of data, including a test done three years ago with modern instrumentation. This adds to the database we are creating by testing injectors, turbo pumps and other 3D-printed rocket engine parts of interest to both Nasa and industry,” said NASA Marshall Space Flight Center test requestor Chris Protz.

"The test series was conducted by NASA at the request of Dynetics and Aerojet Rocketdyne, which designed and manufactured the 3D printed gas generator. "

[catdlr]

NASA Tests Provide Rare Opportunity to Get 3-D Printed Part Comparison Data

Published on Sep 16, 2015
The gas generator to an F-1 engine is test-fired this September at NASA's Marshall Space Flight Center in Huntsville, Alabama. Although the engine was originally built to power the Saturn V rockets during America's missions to the moon, this test article had new parts created using additive manufacturing, or 3-D printing, to test the viability of the technology for building new engine designs.

[Prober]

The Power of 3D Printing to Accelerate NASA Plans for Manned Mars Trip
http://3dprint.com/98109/3d-print-for-manned-mars-trip/

"New breakthroughs have a lot to do with this optimism, as the team has broken new barriers a la 3D printing, due to the creation of a 3D printed turbo pump meant for the launch engine. It has been tested with success and Robertson points out that it functions in the launch engine as one of the most complex components."

“Moving from liquid hydrogen to methane on the turbo pump allows the hardware to be used as a springboard for a variety of missions,” she says, “including landing on Mars.”

[Prober]

Another SLS story.....

Metal 3D Printing is Helping NASA Blast Off into Space
http://3dprintingindustry.com/2015/10/19/metal-3d-printing-is-helping-nasa-blast-off-into-space/

"In order to evolve the hardware of their space engines, NASA is experimenting with the process of Direct Metal Laser Sintering (DMLS), a 3D printing method that utilizes space-grade metal materials such as titanium, stainless steel, cobalt chrome, and more. The Marshall team claims to be constantly pushing the envelope for potential 3D printing applications,

 The injectors, which traditionally take six to nine months to manufacture, were 3D printed and built within 10 days with DMLS, and, also, proved to be much sturdier than cast parts under stressful environments. "

[Prober]

Ready for Blast Off? SpaceX 3D Printed SuperDraco Thrusters Prove Themselves Further at Texas Rocket Facilityhttp://3dprint.com/105511/spacex-3d-printed-superdraco/

"Now, SpaceX has officially finished development testing of the four pairs of SuperDracos, at their McGregor, Texas facility. They report 27 test fires and evaluations with various cycles. Considering this is the system that would be used to save people on board in space, SpaceX–and NASA–are of course taking no chances and have been working on the design and refinements of these components and engines diligently."

[Prober]

MTI Partners with NASA Johnson on 3D Printed Engine -
http://www.parabolicarc.com/2015/11/21/mti-partners-nasa-johnson-3d-printed-engine/#sthash.stdL5h0d.dpuf

"MTI has produced two such components for the engineering team at NASA JSC out of Inconel 718. The material is robust enough to withstand extreme heat and corrosive environments without losing its rigidity or becoming brittle. “The Project provided amazing dialogue and collaboration between the NASA and MTI development teams and the results were excellent” said Gary Cosmer, Chief Executive Officer for Metal Technology (MTI) . - "

[Prober]

NASA Gives Aerojet Rocketdyne $1.6 Billion Contract for New, Improved, 3D Printed RS-25 Engines
http://3dprint.com/107454/nasa-aerojet-rocketdyne/

The new, sleeker engines, which Aerojet will be building for future SLS missions, will be more affordable and will require fewer parts and welds than the older ones, thanks in part to state-of-the-art manufacturing technologies including five-axis milling machines, digital X-rays… and, of course, 3D printing.

[Scylla]

Aerojet Rocketdyne Completes Build of 3-D Printed Parts for Orion Spacecraft

SACRAMENTO, Calif., Dec. 1, 2015 (GLOBE NEWSWIRE) -- Aerojet Rocketdyne, a subsidiary of Aerojet Rocketdyne Holdings, Inc. (NYSE:AJRD), has completed 12 additively manufactured production nozzle extensions for use aboard the Orion spacecraft. The nozzle extensions are part of Orion's crew module reaction control system that Aerojet Rocketdyne is building for Lockheed Martin and NASA.

"These components are the first additively manufactured parts we have provided for the Orion spacecraft," said Julie Van Kleeck, vice president of Advanced Space & Launch Programs at Aerojet Rocketdyne. "The reaction control system on the Orion crew module is critical for astronaut crew safety, which is why we have invested heavily in the development and testing of additively manufactured components."

The 12 nozzles were produced on a single additive manufacturing machine in just three weeks, which represents a roughly 40 percent reduction in production time when compared with using conventional manufacturing techniques. The company will next conduct a series of inspections and hot-fire tests to qualify the components for use aboard Orion's Exploration Mission-1 test flight in 2018.
http://www.rocket.com/article/aerojet-rocketdyne-completes-build-3-d-printed-parts-orion-spacecraft

[Prober]

US Air Force Taps Aerojet Rocketdyne to Set 3D Printed Rocket Engine Standards
http://3dprint.com/114114/aerojet-rocketdyne-standards/

"Aerojet Rocketdyne just received a $6 million contract from the US Air Force to define 3D printed rocket engine component standards. These new standards will be used to qualify any components used in liquid-fueled rocket engine applications created using additive manufacturing technology. The contract was awarded by the US Air Force Booster Propulsion Technology Maturation Broad Agency Announcement, which is part of an all-inclusive Air Force strategy to shift away from the Russian-made RD-180 engines that are currently being used on the Atlas V launch vehicle and towards new domestically produced options."

[Prober]

Dude, Where’s My JetPack? Check Out Your 3D Printed JB-9 at CES 2016 via JetPack

"While in testing, the JetPack J-9 so far has only been able to stay in the air for ten minutes, but the creators do indeed see it as a viable type of transportation–and now entirely possible due to 3D printing. Its 3D printed components will be on display today at CES 2016 in Las Vegas. Attendees will be able to see what is making this new device possible, with a compact and lightweight construction that is still powerful enough to get someone off the ground with vertical takeoff and landing (VTOL). The JetPack can take you to 10,000 feet and go up to 100 mph–and after you’ve planted yourself safely on terra firma and are ready to head home, it packs easily in your trunk."

[Prober]

Project Orion: NASA’s Mission to Mars Relies on Designs of Past & Future, Powered by 3D Printing
http://3dprint.com/115954/orion-nasas-mars-3d-printing/

article written off the material in this article

http://www.theengineer.co.uk/project-orion-the-next-giant-leap/

[Prober]

Orbital ATK Successfully Tests 3D Printed Hypersonic Engine Combustor
http://3dprint.com/116380/orbital-atk-hypersonic-engine/

"A scramjet combustor needs to be able to maintain stable, steady combustion in extremely volatile conditions at speeds in excess of Mach 5 (3,800 mph), and the Orbital ATK combustor met or exceeded all requirements during the testing.

The engine combustor was manufactured at Orbital ATK’s headquarters in Ronkonkoma, New York, and at the Allegany Ballistics Laboratory in West Virginia. The part was produced via powder bed fusion, an additive manufacturing process that involves using laser beams to fuse together metal powders, one layer at a time. The use of 3D printing allowed for much construction to be completed much more quickly and inexpensively than other manufacturing techniques. It’s a very complex part, but 3D printing allows it to be built with fewer parts, and multiple prototypes can be churned out and tested quickly and cheaply."

[Prober]

The Dragon Can Hover: SpaceX and Their 3D Printed SuperDraco Thrusters Take the Next Step Towards Propulsive Landing
http://3dprint.com/116669/spacex-dragon-2-thrusters/

It takes a lot of work to launch something into space, but it takes just as much, if not more, work to bring it back down to the ground again. SpaceX has been working on new ways to do both....

https://www.youtube.com/watch?v=07Pm8ZY0XJI&feature=youtu.be

[Prober]

Note that although "3D printing" is fairly new you should keep in mind that additive techniques are at least half a century old.

Quite a lot of Aerojet designs used a combination of photoetched foils diffusion bonded into stacks.

The technology is also used by Velocisys and Meggit to build "printed circuit" heat exchangers and chemical reactors to deliver so called "process intensification."

Personally I always thought Aerojet could have pushed it much harder. They tended to do the stuff flat and then press (or use high pressure gas) to get it to shape.

Obvious extensions that came to mind were :-

Constructing parts as blocks but with either the final part inside the block, or internal cavities, defined by "perforations" around the outline. The little segments left holding parts inside the block would be quick to etch away, freeing the component.

Stretching or bending the unbonded foils should be much easier than doing it to the finished product, provided layer alignment can be preserved. It would mean that once the layers were bonded together they would need to have their edges trimmed to give the right size.

A technique in MEMS mfg is the use of "sacrificial" layers that can be preferentially etched to release objects.

Making structures that are curved as you go down the layers smoothly is probably too difficult. However by using a smaller number of masks could give a more viable "stepped" structure. Those steps should be preferentially etched, giving a (relatively) smooth result.

OTOH curves in the plane are relatively simple. Generally curves give smoother fluid flow.

It should be possible to fabricate in situ sensors based on fluids effects on the resonance frequencies of various structures, being driven and read by various acoustic transducers. Embedded electrical sensors are likely to more difficult due to the need to create insulating and encapsulating layers inside the structures.

By combining sub units split along different planes it would be possible to make more complex structures. this is relevant because of the difficulty of putting curves through layers.

Layer thickness can also be varied. Historically they have been foils the same thickness, but they could be substantially thicker, from a few 0.002" up to say 1 or 2 mm thick.

It should be possible to dispense with a photo resistant and go with a "direct write" exposure of the foils in a liquid, with the laser activating the liquid to etch the foil.

While these methods don't have the total flexibility of metal deposition of 3D printing they are likely to be much faster to produce a large unit quickly (or many small units as a block).

Just some possibilities which are also additive but not 3D printing.

I got the chance to try "platelet" fabrication technology in 1998-99 when we built this engine, which was LOX cooled, 2400 psia Pc design pressure, 6.6K-lbf.  As can be seen from the photos, individual copper foils were assembled in a stack and then diffusion bonded together.  It wasn't cheap at the time costing about $80K, but we fired it 40 times and it worked well.

Edit: spelling

http://forum.nasaspaceflight.com/index.php?topic=33141.msg1498154#msg1498154

[Prober]

AeroJet Rocketdyne Successfully Test-Fires 3D Printed Rocket Injector
http://tinyurl.com/zv4zctt


"Their latest hot-fire test has demonstrated that a core main injector, 3D printed for use in their RL10 development engine, is suited for use in large rocket engines.

The core main injector was 3D printed using Selective Laser Melting (SLM) technology, allowing the defense manufacturer to 3D print a detailed and complex part capable of withstanding the intense environment of a rocket engine. The part is the result of a $6 million contract with the U.S. Air Force, secured earlier this month, for the 3D printing of parts to be used in liquid-fueled engines. The deal is meant to help the USAF replace Russian-made RD-180 engines for the United Launch Alliance’s Atlas V launch vehicle. During a hot-fire test performed with the USAF and NASA’s Glenn Research Center as part of the RL10 Additive Manufacturing Study (RAMS) program, the team validated the injector’s use in the actual RD-180 engine. "

[Prober]

Finalists Announced for Additive Industries’ Metal 3D Printing Design Contest
http://3dprint.com/123866/additive-industries-finalists/

"In the Professional category, the Spanish team ATOS SE showed how to benefit from the additive manufacturing capabilities by creating a new integrated orientation system concept, which unifies a multiple parts solution into a one-part design named “Aerospace Integrated Bearing.” Germany-based TUHH – Liebherr (Technical University of Hamburg-Harburg) optimized the design of the bell crank for an Airbus Helicopter for weight and cost reduction. The third finalist in the Professional category, American firm Smith & Nephew, developed a regenerative liquid rocket engine and designed the light-weight, regenerative cooling liquid rocket nozzle and combustion chamber."

[Prober]

Update article on Rocketlabs

http://forum.nasaspaceflight.com/index.php?topic=34421.msg1359569#msg1359569

Rocket Lab Preps to Send 3D Printed Rocket into Space


http://3dprintingindustry.com/2016/03/25/rocket-lab-preps-to-send-3d-printed-rocket-into-space/?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+3dPrintingIndustry+%283D+Printing+Industry%29


"To create the thrust chamber, injector, turbopumps, and main propellant valves, Rocket Lab relied on Arcam’s electron beam melting technology, 3D printing the components from titanium alloys. Though most of the cost savings come from the use of the electric battery, altogether these innovations have reduced the cost of launching the rocket to just $4.9 million per launch (compared to SpaceX’s $54 million and ULA’s $225 million). These savings could potentially be passed onto the customer, making it less expensive to send small payloads into space.


On March 22, Rocket Lab announced that the Rutheford had completed its qualification tests, publishing the above video of a hot fire test in which the engine was fired for more than two and a half minutes. As a result, the company has planned to launch Electron from their site in New Zealand in the middle of this year. If all goes well, Electron will send satellites made by Spire into Earth orbit over the course of twelve missions from late 2016 to 2017."


Edit add linkage

[Prober]

Looks like something up in Colorado?


http://www.ursamajortechnologies.com/#home


https://www.instagram.com/ursamajortechnologies/[/size]

[Prober]

mostly a rehash story
Rocket engine completely 3D printed


http://3dprintingindustry.com/2016/05/23/rocket-engine-completely-3d-printed/?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+3dPrintingIndustry+%283D+Printing+Industry%29

[Alf Fass]

The article that Prober linked to above has been moved to here:
http://3dprintingindustry.com/news/rocket-engine-completely-3d-printed-79813/

[Prober]

The article that Prober linked to above has been moved to here:
http://3dprintingindustry.com/news/rocket-engine-completely-3d-printed-79813/

even better this one....


Rocket Lab’s Electron Rocket Launch System & 3D Printed Rutherford Engine to Blast Off Later This Year


https://3dprint.com/135721/rocket-labs-electron-rocket/

[Prober]

SKYLON Spaceplane inches closer to orbit thanks to 3D printed injector


http://3dprintingindustry.com/news/skylon-spaceplane-inches-closer-orbit-thanks-3d-printed-injector-88036/

[Prober]

Vector Space Systems Successfully Launches Sub-Orbital Satellite Prototype with 3D Printed Injector


https://3dprint.com/144895/vector-3d-printed-injector/


Vector Space Systems 3D printed a cheap mini rocket

https://3dprintingindustry.com/news/vector-space-systems-3d-printed-a-cheap-mini-rocket-91619/

Edit: add 2nd article & pics

[Prober]

Aerojet Rocketdyne to Mature 3D Printed MPS-130 CubeSat Propulsion System for NASA


https://3dprint.com/145962/aerojet-rocketdyne-nasa/

[Prober]

Linkage to this full story...




http://forum.nasaspaceflight.com/index.php?topic=33141.msg1571188#msg1571188

[Prober]

CubeCab Plans to Put Lots of CubeSats into Orbit with a Small 3D Printed Rocket and a Retired Fighter Jet


https://3dprint.com/147684/cubecab-cubesat-rocket-launch/

[Prober]

NASA Fires Up 3D Printed Rocket Engine for Latest Series of Tests
https://3dprint.com/160079/nasa-3d-printed-engine-tests/


"In the latest tests, the engine was fired for 30 seconds (although it could have gone longer), allowing the engineers at NASA’s Marshall Space Flight Center to obtain, for the first time, information about how the engine’s 3D printed components perform together during a longer-duration burn. With the exception of the new combustion chamber, all of the major components in the test engine were 3D printed, including the fuel injector, fuel turbopump, valves, and more."

[lars.lauritsen.1]

Wow this is so awesome stuff 😊 👍

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