a few remarks concerning the idea of 3dprinting :-printing in quarter parts is not a good idea, because of the increased warping, due to not being a full circular object. The thermal tension in a fully circular object cancel each other out (more or less). Printing only a quarter will make it difficult to get all piece join up nicely.-secondly, you might want the outside of the part designed as a flat part, so you can print it without the need for supports. You want to print this with the inside upwards. -You'll need to pay special attention to where you put your seams (the points your printhead moves from layer to layer)-with FDM fillament printing, always expect a small hick-up or imperfection somewhere, so you'll need to think about post processing too. -I'm worried about the thermal stability when the EMdrive is operational as most thermoplastics tend to deform easily when they reach 100° C. -As last hint , regardless my above concern, I'd suggest printing with PETG to minimize thermal warping. PLA tends to be brittle (fastening bolts might crack it) and ABS is notorious for thermal warping...-to get a good surface finish, I suggest using a spray car putty and some fine sanding paper. then coat it with a conductive paint, then copper plate it...
Harbin Institute of Technology has applied for two emdrive patents.
Quote from: oyzw on 06/05/2017 12:35 amHarbin Institute of Technology has applied for two emdrive patents.I did try to convert the PDFs to English by uploading them to google translate. It didn't do it. If anyone else has other means of doing it ...
Quote from: Flyby on 06/05/2017 07:01 ama few remarks concerning the idea of 3dprinting :-printing in quarter parts is not a good idea, because of the increased warping, due to not being a full circular object. The thermal tension in a fully circular object cancel each other out (more or less). Printing only a quarter will make it difficult to get all piece join up nicely.-secondly, you might want the outside of the part designed as a flat part, so you can print it without the need for supports. You want to print this with the inside upwards. -You'll need to pay special attention to where you put your seams (the points your printhead moves from layer to layer)-with FDM fillament printing, always expect a small hick-up or imperfection somewhere, so you'll need to think about post processing too. -I'm worried about the thermal stability when the EMdrive is operational as most thermoplastics tend to deform easily when they reach 100° C. -As last hint , regardless my above concern, I'd suggest printing with PETG to minimize thermal warping. PLA tends to be brittle (fastening bolts might crack it) and ABS is notorious for thermal warping...-to get a good surface finish, I suggest using a spray car putty and some fine sanding paper. then coat it with a conductive paint, then copper plate it...These are all very good points. Thank you. The way I see it, this can go several ways. The most obvious route is to 3D print the parts and simply cover them with EMI shielding copper conductive adhesive tape. Alternatively, one could 3D print, sand, and then copper plate. Yet another option is to 3D print and then use a process like the Virtual Foundry (http://www.thevirtualfoundry.com/) to make solid copper parts. The last option, and the best route in my opinion, is to 3D print wax copies of the end plates and then use the lost wax process to create parts which are then machined to exact specifications.
I'm pretty deep "in the weeds" right now. I will conduct a series of low powered tests (2.5W) this week. Then I will work on incorporating the new 30W amplifier. I have also been working on STL files for 3D printing the spherical endplates. Due to the large size and tight tolerances, I have had to cut the end plates into fourths so that it can be printed using the prusa i3 mk2 platform.
CN105775171A Propelling system assisting in reducing weight of propelling system and changing degree and direction of thrust
Quote from: AnalogMan on 06/05/2017 01:06 pmCN105775171A Propelling system assisting in reducing weight of propelling system and changing degree and direction of thrustThis looks like an emdrive based reaction control system.
...These are all very good points. Thank you. The way I see it, this can go several ways. The most obvious route is to 3D print the parts and simply cover them with EMI shielding copper conductive adhesive tape. Alternatively, one could 3D print, sand, and then copper plate. Yet another option is to 3D print and then use a process like the Virtual Foundry (http://www.thevirtualfoundry.com/) to make solid copper parts. The last option, and the best route in my opinion, is to 3D print wax copies of the end plates and then use the lost wax process to create parts which are then machined to exact specifications.
These are all very good points. Thank you. The way I see it, this can go several ways. The most obvious route is to 3D print the parts and simply cover them with EMI shielding copper conductive adhesive tape. Alternatively, one could 3D print, sand, and then copper plate. Yet another option is to 3D print and then use a process like the Virtual Foundry (http://www.thevirtualfoundry.com/) to make solid copper parts. The last option, and the best route in my opinion, is to 3D print wax copies of the end plates and then use the lost wax process to create parts which are then machined to exact specifications.
For monomorphic's test, I am especially interested in the direction-relative-to-Earth-magnetic-field null test. It's a pity monomorphic did not carry out this albeit easy test.
I'm about to have access to a 3D printer that has a 12" (40cm) square build area and can print higher temp materials like PETG and Nylon.
Quote from: Mark7777777 on 06/05/2017 12:45 pmQuote from: oyzw on 06/05/2017 12:35 amHarbin Institute of Technology has applied for two emdrive patents.I did try to convert the PDFs to English by uploading them to google translate. It didn't do it. If anyone else has other means of doing it ...Managed to find machine translations for both patents:CN 105790717 A A microwave-based adaptive tuning system for a non-working microwave thruster and a microwave source adaptive tuning method using the systemhttp://www.google.com/patents/CN105790717ACN105775171A Propelling system assisting in reducing weight of propelling system and changing degree and direction of thrusthttp://www.google.com/patents/CN105775171A[Edit: added second patent link]
Would people not think it's a lot of effort to go through and author and file those patents if Harbin Institute of Technology hadn't seen real-life evidence of thrust themselves? Maybe in their own labs?https://en.m.wikipedia.org/wiki/Harbin_Institute_of_Technology"HIT is consistently ranked as one of the top universities in the country [3] with a focus on science and engineering.[4][5][6] HIT was ranked 7th in the Best Global Universities for Engineering by U.S. News in 2016.[7] HIT is one of only a handful of universities in the world that have designed, built, and launched their own satellites (in 2004, 2008 and 2013)."
Quote from: VAXHeadroom on 06/05/2017 04:11 pmI'm about to have access to a 3D printer that has a 12" (40cm) square build area and can print higher temp materials like PETG and Nylon. The big end, with 3.5cm flanges, is 14.5" (36.5cm) in diameter. 12" is 30cm not 40cm, so I don't think it could be printed even with that printer.
Quote from: qraal on 06/02/2017 09:26 amHiI seem to remember that preprint too...The quantum vacuum as the origin of the speed of lightQuoteWe show that the vacuum permeability and permittivity may originate from the magnetization and the polarization of continuously appearing and disappearing fermion pairs. We then show that if we simply model the propagation of the photon in vacuum as a series of transient captures within these ephemeral pairs, we can derive a finite photon velocity. Requiring that this velocity is equal to the speed of light constrains our model of vacuum. Within this approach, the propagation of a photon is a statistical process at scales much larger than the Planck scale. Therefore we expect its time of flight to fluctuate. We propose an experimental test of this prediction.Thanks for the lead. Will have a read too.Quote from: WarpTech on 06/01/2017 11:13 pmQuote from: qraal on 06/01/2017 11:01 amHi GuysNormally I lurk and enjoy the show, but I spotted this pertinent preprint on the arXiv today:Theoretical calculation of the fine-structure constant and the permittivity of the vacuumAn intriguing suggestion at the end is that considering the vacuum in this manner allows for a variable speed of light in the very early universe. But the fact that the Fine Structure Constant can be computed from assuming the vacuum is filled with virtual positronium (some ~10^39 per cubic metre) does lend some credence to Harold White's suggestions about how EM-Drives and kin *might* work.I haven't sat down and compared them yet, but this sounds very similar to Marcel Urban, et. al.'s paper:The quantum vacuum as the origin of the speed of light - 2013https://link.springer.com/article/10.1140%2Fepjd%2Fe2013-30578-7If anyone has the time to compare them, please keep me in the loop.Thanks!I wrote to the authors regarding their work vs the work of Dr Fern and Prof. Woodward, recently published in JBIS. Because their claim that there are 1.11 x 1039 parapositronium "on mass shell" atoms per cubic meter, results in a cubic meter of empty spacing having an instantaneous rest mass of over 2 million metric tons. I'm looking forward to a response.
HiI seem to remember that preprint too...The quantum vacuum as the origin of the speed of lightQuoteWe show that the vacuum permeability and permittivity may originate from the magnetization and the polarization of continuously appearing and disappearing fermion pairs. We then show that if we simply model the propagation of the photon in vacuum as a series of transient captures within these ephemeral pairs, we can derive a finite photon velocity. Requiring that this velocity is equal to the speed of light constrains our model of vacuum. Within this approach, the propagation of a photon is a statistical process at scales much larger than the Planck scale. Therefore we expect its time of flight to fluctuate. We propose an experimental test of this prediction.Thanks for the lead. Will have a read too.Quote from: WarpTech on 06/01/2017 11:13 pmQuote from: qraal on 06/01/2017 11:01 amHi GuysNormally I lurk and enjoy the show, but I spotted this pertinent preprint on the arXiv today:Theoretical calculation of the fine-structure constant and the permittivity of the vacuumAn intriguing suggestion at the end is that considering the vacuum in this manner allows for a variable speed of light in the very early universe. But the fact that the Fine Structure Constant can be computed from assuming the vacuum is filled with virtual positronium (some ~10^39 per cubic metre) does lend some credence to Harold White's suggestions about how EM-Drives and kin *might* work.I haven't sat down and compared them yet, but this sounds very similar to Marcel Urban, et. al.'s paper:The quantum vacuum as the origin of the speed of light - 2013https://link.springer.com/article/10.1140%2Fepjd%2Fe2013-30578-7If anyone has the time to compare them, please keep me in the loop.Thanks!
We show that the vacuum permeability and permittivity may originate from the magnetization and the polarization of continuously appearing and disappearing fermion pairs. We then show that if we simply model the propagation of the photon in vacuum as a series of transient captures within these ephemeral pairs, we can derive a finite photon velocity. Requiring that this velocity is equal to the speed of light constrains our model of vacuum. Within this approach, the propagation of a photon is a statistical process at scales much larger than the Planck scale. Therefore we expect its time of flight to fluctuate. We propose an experimental test of this prediction.
Quote from: qraal on 06/01/2017 11:01 amHi GuysNormally I lurk and enjoy the show, but I spotted this pertinent preprint on the arXiv today:Theoretical calculation of the fine-structure constant and the permittivity of the vacuumAn intriguing suggestion at the end is that considering the vacuum in this manner allows for a variable speed of light in the very early universe. But the fact that the Fine Structure Constant can be computed from assuming the vacuum is filled with virtual positronium (some ~10^39 per cubic metre) does lend some credence to Harold White's suggestions about how EM-Drives and kin *might* work.I haven't sat down and compared them yet, but this sounds very similar to Marcel Urban, et. al.'s paper:The quantum vacuum as the origin of the speed of light - 2013https://link.springer.com/article/10.1140%2Fepjd%2Fe2013-30578-7If anyone has the time to compare them, please keep me in the loop.Thanks!
Hi GuysNormally I lurk and enjoy the show, but I spotted this pertinent preprint on the arXiv today:Theoretical calculation of the fine-structure constant and the permittivity of the vacuumAn intriguing suggestion at the end is that considering the vacuum in this manner allows for a variable speed of light in the very early universe. But the fact that the Fine Structure Constant can be computed from assuming the vacuum is filled with virtual positronium (some ~10^39 per cubic metre) does lend some credence to Harold White's suggestions about how EM-Drives and kin *might* work.
Quote from: AnalogMan on 06/05/2017 01:06 pmQuote from: Mark7777777 on 06/05/2017 12:45 pmQuote from: oyzw on 06/05/2017 12:35 amHarbin Institute of Technology has applied for two emdrive patents.I did try to convert the PDFs to English by uploading them to google translate. It didn't do it. If anyone else has other means of doing it ...Managed to find machine translations for both patents:CN 105790717 A A microwave-based adaptive tuning system for a non-working microwave thruster and a microwave source adaptive tuning method using the systemhttp://www.google.com/patents/CN105790717ACN105775171A Propelling system assisting in reducing weight of propelling system and changing degree and direction of thrusthttp://www.google.com/patents/CN105775171A[Edit: added second patent link]Would people not think it's a lot of effort to go through and author and file those patents if Harbin Institute of Technology hadn't seen real-life evidence of thrust themselves? Maybe in their own labs?https://en.m.wikipedia.org/wiki/Harbin_Institute_of_Technology"HIT is consistently ranked as one of the top universities in the country [3] with a focus on science and engineering.[4][5][6] HIT was ranked 7th in the Best Global Universities for Engineering by U.S. News in 2016.[7] HIT is one of only a handful of universities in the world that have designed, built, and launched their own satellites (in 2004, 2008 and 2013)."
https://physics.stackexchange.com/questions/236/how-does-positronium-existIt appears while positronium can exist, it has a half-life from .125ns to 142ns if the last poster is correct. What is interesting is depending on the local available energy these positronium can pop in and out of existence. To me that suggest something similar to phantom particles with zero rest mass but some transient mass depending on the local available energy.