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#360
by
rfmwguy
on 18 Mar, 2016 22:42
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Couldn't I fabricate a board with some duroid based on the DXF?
I'd recommend BeO or Alumina...be very careful with the BeO. Duroid might have trouble with the temp. The expansion coefficient of duroid versus aluminum (heat sink) might be an issue, not sure (?). Also, be sure to enclose it like another user said. No mountain oysters! 
Edit - here's stuff similar to what I used to work with, a test fixture for VNAs type design might be a good way to go, just build an enclosure. Note the copper heatsink on the bottom. Lots of places to find either copper or aluminum, finned stuff.
Why re-invent the wheel? The manufacturer of the device provides the artwork to manufacture the board, including the material used. Sure, you could create a huge hassle and expense for yourself by using a ceramic substrate, but if it were necessary don't you think the manufacturer would have done it, too?
If you do decide to go with a ceramic substrate, you'll need a complete re-design of the board layout. Different substrate dielectric constants require different strip-line dimensions.
50 Ohm ceramic transmission lines on a substrate are a commodity. Here's one: http://www.usmicrowaves.com/microstrip/50_ohm_impedance_microstrip_microwave_transmission_line_z50-25-171xxx.htm there are many more. Ceramic provides a better thermal conductivity and frequency response. Its not a huge expense nor reinvention of the wheel. Alumina Nitride is a safe ceramic. A little indium solder on the ground plane and your good to go.
Dave, I'm thinking you didn't even take a cursory glance at the manufacturer provided artwork? It has rectangular cutouts, ground vias, mounting holes, cap/ind tuning stubs, impedance transistion strips, etc. Not trivial in ceramic. The last item I had made in alumina of similar size and complexity cost ~$5K.
Telling monomorphic to basically buy some pre-printed 50 ohm stripline on alumina (with the stripline being WAY too thin anyway), tack it to a heatsink with indium solder, and Bob's your uncle is a bit...weird.
Of course I did not tell him to buy ceramic, but think about the possibility. I also did not say tack it. There is a reflow process I'm sure you're familiar with. He is a big boy, he's smart enough to make his own decisions without people lobbying for one methodology or another. His design, his budget and his decision. Simple as that.
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#361
by
zen-in
on 19 Mar, 2016 01:33
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Nor is the RF board in the pic ceramic. I'm unclear why Dave thought it necessary to gainsay the manufacturer of the device and recommend a very expensive alternative to the material actually recommended by the device manufacturer. His reasoning got so circular it was a waste of time trying to follow it. Good luck, monomorphic!
It does have 4 holes drilled through the Copper heat spreader for attaching an Aluminum heat sink. Most of the HF through UHF power amplifiers I have seen use this same construction; just different transistors and matching techniques. I have several 1.9 - 2.2 GHz 10 Watt amps that are all ceramic inside. It's difficult to see what is going on inside but they do put out the rated class C power.
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#362
by
Carl G
on 19 Mar, 2016 17:04
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Small blog sites will often leech comments made on this site and overblow them in an attempt to get linked by larger sites like this. The one in question does it often, and as usual misrepresents it. Removed the reference as it provides no value to the thread.
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#363
by
wallofwolfstreet
on 20 Mar, 2016 15:20
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Just as an FYI, a letter written to New Scientist on why EADS Astrium didn't pursue the emdrive was recently posted by a helpful redditor. It's short so I will post it here:
Published 18 October 2006
Emdrive? No thanks
The article about Roger Shawyer implies that EADS Astrium suppressed this miracle drive for nefarious business reasons (9 September, p 30). The truth (sorry, conspiracy theorists!) is rather different. As the then technical director of Astrium, I reviewed Roger’s work and concluded that both theory and experiment were fatally flawed. Roger was advised that the company had no interest in the device, did not wish to seek patent coverage, and in fact did not wish to be associated with it in any way. The letters you have published point out some of the issues (7 October, p 24).
I was also surprised by the “end of wings and wheels?” tagline on the cover. Even if the device did work, the thrust/power ratio claimed by Roger would make it impractical for any terrestrial transport application.
https://www.newscientist.com/letter/mg19225740-300-emdrive-no-thanks/
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#364
by
TheTraveller
on 20 Mar, 2016 17:20
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Just as an FYI, a letter written to New Scientist on why EADS Astrium didn't pursue the emdrive was recently posted by a helpful redditor. It's short so I will post it here:
Published 18 October 2006
Emdrive? No thanks
The article about Roger Shawyer implies that EADS Astrium suppressed this miracle drive for nefarious business reasons (9 September, p 30). The truth (sorry, conspiracy theorists!) is rather different. As the then technical director of Astrium, I reviewed Roger’s work and concluded that both theory and experiment were fatally flawed. Roger was advised that the company had no interest in the device, did not wish to seek patent coverage, and in fact did not wish to be associated with it in any way. The letters you have published point out some of the issues (7 October, p 24).
I was also surprised by the “end of wings and wheels?” tagline on the cover. Even if the device did work, the thrust/power ratio claimed by Roger would make it impractical for any terrestrial transport application.
https://www.newscientist.com/letter/mg19225740-300-emdrive-no-thanks/
Surprising EADS (Alvin Wilby) didn't visit Roger (just a short flight across the channel) and view the Demonstrator EmDrive spinning on the rotary table? Then again it seems EADS / AirBus has their own propellantless drive tech patent application:
7,571N/kW!
http://tinyurl.com/hksu5reWonder if they were working on this when they told Roger "No Thanks"?
As a side note James Woodward has been granted a US patent on his propellantless drive tech:
http://tinyurl.com/jmdbdheSo it seems we now have at least 3 propellantless drive techs in existence:
Roger Shawyer, Satellite Propulsion Research
Jean-Francois Geneste, EADS / AirBus
James Woodward, Space Studies Institute
May the best tech win.
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#365
by
Rodal
on 20 Mar, 2016 17:48
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The US patent application prosecution history for the Geneste ( US 20150260168 Assignee: EADS) application does not bode well for its future: readers please note that the broader, first 13 claims have already been cancelled.
(A patent is literally infringed only when the accused action or device meets all of the elements of the invention as defined by the patent claims.)
As to why EADS did not pursue Shawyer's ideas, the letter to New Scientist by Alvin Wilby answers this completely:
The article about Roger Shawyer implies that EADS Astrium suppressed this miracle drive for nefarious business reasons (9 September, p 30). The truth (sorry, conspiracy theorists!) is rather different. As the then technical director of Astrium, I reviewed Roger’s work and concluded that both theory and experiment were fatally flawed. Roger was advised that the company had no interest in the device, did not wish to seek patent coverage, and in fact did not wish to be associated with it in any way. The letters you have published point out some of the issues (7 October, p 24).
I was also surprised by the “end of wings and wheels?” tagline on the cover. Even if the device did work, the thrust/power ratio claimed by Roger would make it impractical for any terrestrial transport application.
That is a very potent statement: <<both theory and experiment were fatally flawed.>>
As Meberbs recently pointed out, even something as simple as a force balance is incorrectly addressed by Shawyer. (*)
It is noteworthy that Wilby just doesn't say that they decided not to pursue Shawyer's ideas, but he goes as far as stating:
in fact did not wish to be associated with it in any way.
It is difficult to conceive what else could a Technical Director of a major aerospace company have stated to make it clear that he thinks that there is something very wrong and to distance himself.
________
(*) I still don't understand why Mr. Shawyer, upon the negative reception to his "theoretical explanation" and his NewScientist article, didn't seek cooperation from British Universities. The UK has some outstanding universities: why doesn't he go to Cambridge University for example, and tell them: I have an experiment that shows a force, but my explanation is not well received in the scientific/engineering community, can you help me with a better explanation and to show that my experimental results are valid?
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#366
by
chavv
on 20 Mar, 2016 18:44
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That patents like those can be received is simply a prove how dumb is the US patent service.
At least in Em Drive there is some hope that the effect is real & explainable by science
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#367
by
TheTraveller
on 20 Mar, 2016 18:53
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(*) I still don't understand why Mr. Shawyer, upon the negative reception to his "theoretical explanation" and his NewScientist article, didn't seek cooperation from British Universities. The UK has some outstanding universities: why doesn't he go to Cambridge University for example, and tell them: I have an experiment that shows a force, but my explanation is not well received in the scientific/engineering community, can you help me with a better explanation and to show that my experimental results are valid?
Just maybe that has been done.
Ah to hell with the games. Roger told me that has been done. In fact several universities have been involved. That said I believe Roger may be holding some of the theory stuff very close to his chest. Which I perfectly understand. I mean it is, in the end, about $$.
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#368
by
wallofwolfstreet
on 20 Mar, 2016 19:32
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Ah to hell with the games. Roger told me that has been done. In fact several universities have been involved. That said I believe Roger may be holding some of the theory stuff very close to his chest. Which I perfectly understand. I mean it is, in the end, about $$.
Rogers first patent on an emdrive like technology was in 1989. He's had almost thirty years to come up with a more coherent theoretical explanation for the emdrive, and yet in his latest paper from July of 2015 (
see here), he offers up the exact same nonsense theoretical explanation he has offered up since day one.
So if Roger is "holding some theory stuff very close to his chest", then are we to believe that in your opinion the most recent paper contains an intentionally incorrect theoretical explanation? Because I can guarantee you no one from any of these collaborating universities would have let him use such a trivially incorrect explanation. So how to reconcile this issue? If he knows his theoretical explanation is bogus, why is he still using it in his published works?
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#369
by
TheTraveller
on 20 Mar, 2016 19:39
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Ah to hell with the games. Roger told me that has been done. In fact several universities have been involved. That said I believe Roger may be holding some of the theory stuff very close to his chest. Which I perfectly understand. I mean it is, in the end, about $$.
Rogers first patent on an emdrive like technology was in 1989. He's had almost thirty years to come up with a more coherent theoretical explanation for the emdrive, and yet in his latest paper from July of 2015 (see here), he offers up the exact same nonsense theoretical explanation he has offered up since day one.
So if Roger is "holding some theory stuff very close to his chest", then are we to believe that in your opinion the most recent paper contains an intentionally incorrect theoretical explanation? Because I can guarantee you no one from any of these collaborating universities would have let him use such a trivially incorrect explanation. So how to reconcile this issue? If he knows his theoretical explanation is bogus, why is he still using it in his published works?
You never heard of Industrial Secrets?
Roger is not a Publish or Die academic. Why should he give away the combination to the vault?
BTW I have advised him to get on his skates and open the commercial propellantless drive market NOW as there are 2 other propellantless drive techs coming on stream.
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#370
by
wallofwolfstreet
on 20 Mar, 2016 19:58
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You never heard of Industrial Secrets?
Roger is not a Publish or Die academic. Why should he give away the combination to the vault?
BTW I have advised him to get on his skates and open the commercial propellantless drive market as there are now 2 other propellantless drive techs coming on stream.
Because he is publishing works in conferences and in patents and in at least one academic journal? Is he or is he not intentionally using an incorrect physical explanation in his published works? If he is, than what else might be left intentionally incorrect?
If someone publishes articles pretending to give a theoretical explanation, but it's only a smoke screen for your "industrial secret", then they're lying. Simple as that.
BTW I have advised him to get on his skates and open the commercial propellantless drive market as there are now 2 other propellantless drive techs coming on stream.
You can't be serious. There have been propellantless drive technologies "coming on stream" since the 1920's when T. T. Brown first started the whole "asymmetric capacitor" concept. The patent literature is absolutely replete with propellantless drive applications, ranging from countless gyroscopic propulsion designs to more esoteric magic superconductor designs.
Ever hear of Sandy Kidd or Eric Laithwaite? Dr. Laithwaite was actually a successful electrical engineer (major role in inventing the mag lev train) who was bestowed the honour of giving a lecture to the Royal Institution. Unfortunately, he was already off the deep end and started claiming gyroscopes could be used in propulsion applications (P.S. they can't).
Hell, Dr. Laithwaite even had the same dubious honor of getting to do a BBC doc on the subject as well!
I don't know who said it, but it was someone on this forum:
propellantless propulsion is just perpetual motion for space nerds
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#371
by
rfmwguy
on 21 Mar, 2016 01:47
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The time and expense needed to create a patent plus allowing the company's name on it for the world to see makes me wonder...was a working prototype built? Airbus doesn't strike me as a company that would engage in frivolous patents on non-working concepts. If they do, shame on them...its setting a poor example for the world to see. There is only one other possibility, they have something. The 2006 article in newscientist should have discredited the patent app...yet it was published in 2015. Boeing once had an emdrive and silence since then except for a quote they aren't working with shawyer. 2 of the worlds largest aerospace companies have been evaluating peopellantless propulsion...perpetual motion machines for space nerds...why would they have even tried? And why is there a 2015 patent on the books? Dismissing this as "nothing to see here" is either naive or wishful opinion. A simple interest in a propellantless engine should not have lead to a patent, yet it did. Perhaps airbus can clarify.
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#372
by
meberbs
on 21 Mar, 2016 02:26
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Dismissing this as "nothing to see here" is either naive or wishful opinion.
You apparently didn't read the patent, you can go look at my summary on the other thread, but this concept is trivially nonsensical.
The cost of a patent is fairly trivial for even a moderate sized company. Big defense contractors will patent basically anything that they think can get through the patent process.
Also, the amount of dysfunction inside these companies can be surprisingly large. It is not worth reading into why did they investigate this or make that decision. (Go check out some of the ULA threads on this site for people trying to pick apart their strategy and arguing about why they make decisions that leave them with limited ability to compete). Silence from Boeing most likely means that they looked into it, realized there was no way it would ever work and have dropped it. If it did work, they might classify some specifics (if the government started funding it, since only the government can classify info), but are unlikely to have taken it completely dark.
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#373
by
Monomorphic
on 21 Mar, 2016 02:33
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Build Update: "NSF-TE311" is well underway. I worked most of the day on the frustum. By far, the side-walls are the most difficult part of the emdrive to fabricate!
Also shown is the first-surface mirror attached to the emdrive that is part of the interferometer.
Pro-tip. If you order your copper from onlinemetals.com, it comes attached to a cardboard honeycomb. Leave it attached and tape it down to make it easier to cut the 1mm copper.
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#374
by
FattyLumpkin
on 21 Mar, 2016 04:22
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Is there a prevailing consensus Emdrive theory of function here on NSF forum? (not rhetorical) Thank you , FL
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#375
by
FattyLumpkin
on 21 Mar, 2016 04:25
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BTW Monomorphic, beautiful work!!! , F L
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#376
by
Chrochne
on 21 Mar, 2016 05:10
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The time and expense needed to create a patent plus allowing the company's name on it for the world to see makes me wonder...was a working prototype built? Airbus doesn't strike me as a company that would engage in frivolous patents on non-working concepts. If they do, shame on them...its setting a poor example for the world to see. There is only one other possibility, they have something. The 2006 article in newscientist should have discredited the patent app...yet it was published in 2015. Boeing once had an emdrive and silence since then except for a quote they aren't working with shawyer. 2 of the worlds largest aerospace companies have been evaluating peopellantless propulsion...perpetual motion machines for space nerds...why would they have even tried? And why is there a 2015 patent on the books? Dismissing this as "nothing to see here" is either naive or wishful opinion. A simple interest in a propellantless engine should not have lead to a patent, yet it did. Perhaps airbus can clarify.
I believe you are right there. I saw this happen in companies I worked for. They discredited the inventors in order to take over their patents later. Zen-In do well to believe in the numbers, but there is always more than that. That is where Trallever is right. It is about the $$.
I would not be suprised if Airbus intention was to discredit him. They done their research well and know that just s little push will damage his reputation even more... I do not have any idealistic visions about the american companies. Money is first motivator for them.
Also I do not think this dabate have any meaning here. Zen-In may I ask you why do you repeatedly bring this subject here? I know you are very sceptical to Em-Drive and that is understatement, but damaging Mr. Shawyer reputation any further do not bring us any closer to solving this anomalous device.
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#377
by
RotoSequence
on 21 Mar, 2016 05:33
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I believe you are right there. I saw this happen in companies I worked for. They discredited the inventors in order to take over their patents later. Zen-In do well to believe in the numbers, but there is always more than that. That is where Trallever is right. It is about the $$.
To play the devil's advocate, can you give an example of the invention, discrediting, and subsequent usage of technology cycle?
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#378
by
Chrochne
on 21 Mar, 2016 05:43
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I believe you are right there. I saw this happen in companies I worked for. They discredited the inventors in order to take over their patents later. Zen-In do well to believe in the numbers, but there is always more than that. That is where Trallever is right. It is about the $$.
To play the devil's advocate, can you give an example of the invention, discrediting, and subsequent usage of technology cycle?
Only on the example from the company where I worked for as I said before. First ever kind of flexible sander that is able to sand concave and convex surface. It is manily used on larger surface as are the yachts for example. It is a different debate than concerning that of the EmDrive. PM me if you want details Mr. Devil.
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#379
by
Stormbringer
on 21 Mar, 2016 09:00
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I believe you are right there. I saw this happen in companies I worked for. They discredited the inventors in order to take over their patents later. Zen-In do well to believe in the numbers, but there is always more than that. That is where Trallever is right. It is about the $$.
To play the devil's advocate, can you give an example of the invention, discrediting, and subsequent usage of technology cycle?
perhaps the windshield wiper and then in a separate example; the interval windshield wiper? There were some corporate vs inventor shenanigins there but i don't remember the precise details.
