A number of our DIYers do have an own setup or are in the process of building it. I proposed this ad-hoc method to have a way to create a very good testing vacuum without any expensive vacuum pumps. This method does not really have anything to do with Mr. Shawyer's or anyone else's device. I'm just going by the principle that what's not there cannot influence the measurements. Why compensate for something, if there is a way to get rid of that something altogether? What plagues EM-drive research is really having to account for a number of annoying effects that hide the mostly miniscule effects. And I still find it worrysome that almost no experiments were performed under vacuum conditions. BTW, if Mr. Shawyer's device is as powerful as you state, I think we would all appreciate a public demonstration with multi-Newton performance anytime soon. As far as I can see, it's just talk talk talk about how wonderful Mr. Shawyer's device is. It's PowerPoint level credibility. That's why I esteem our DIYers so highly on this forum - they actually show their stuff. Quite the opposite of PowerPoint level 'discussions'.Best regards
A few pages back the conversation bounced around Dark Matter.Dark Matter and Dark Energy are invented to explain the facts that various astronomical bodies have the wrong velocity and/or acceleration. So far they are completely undetectable.In the spirit of Occam's Razor, I would suggest that a nicely parsimonious 'explanation' for these phenomena would simply be that Momentum is not conserved in the way we expect under certain circumstances, and that the undetectable stuff really isn't there.I don't think I've seen this idea put like this before, and obviously occurs here because thoughts of breaking CoM are central to the EM Drive discussion.Of course, 'explanation' is in quotes because the immediate step is to start figuring out exactly where momentum might not be conserved. But it makes a change from looking for 'floobie dust'.R.
Quote from: rfmwguy on 10/26/2015 01:58 amQuote from: SeeShells on 10/26/2015 01:51 amThoughts??? I'm considering on putting a top cap to deflect hot air 900 away from the frustum. The beryllium gasket seal between the ceramic top plate and tuning chamber will leak hot air.Forcing hot air horizontally will eventually find an edge and rise. But..if it could be cooled enough before edge was reached...hmmmmThis WEB page gives formula to make estimate of the air velocity in the center of a convective flow : http://www.engineeringtoolbox.com/convective-air-flow-d_1006.htmlThe study of the sensitivity of the formula to its parameters can help to chose a design which reduces the velocity of the convective flow.
Quote from: SeeShells on 10/26/2015 01:51 amThoughts??? I'm considering on putting a top cap to deflect hot air 900 away from the frustum. The beryllium gasket seal between the ceramic top plate and tuning chamber will leak hot air.Forcing hot air horizontally will eventually find an edge and rise. But..if it could be cooled enough before edge was reached...hmmmm
Thoughts??? I'm considering on putting a top cap to deflect hot air 900 away from the frustum. The beryllium gasket seal between the ceramic top plate and tuning chamber will leak hot air.
Perhaps it makes more sense to create a bad vacuum (e.g. one tenth of atmospheric pressure) with a simple and cheap pump in an enclosure with the test article in it? We just want to increase SNR considerably, right? I don't think that a hard vacuum is needed. We just want to get rid of most of the buoyancy for now. My 2 cents .Edit: Actually, it should easily be possible to create a pretty hard vacuum the cheap way:1) 3D-print a metallic enclosure with cooling channels for liquid nitrogen in the walls, perhaps even just the bottom/floor of the enclosure.2) Put an automated, complete test article in it (sorta like a space probe)3) Shut the enclosure and fill it with pure CO2, so that all other gases are pushed out of the enclosure4) Seal the enclosure and start pumping liquid nitrogen through the wall channels. The CO2 freezes out, until there's only solid dry ice left (maybe best only on bottom/floor of enclosure)5) You got vacuum What do you guys think about this method?
Quote from: Mezzenile on 10/26/2015 07:55 amQuote from: rfmwguy on 10/26/2015 01:58 amQuote from: SeeShells on 10/26/2015 01:51 amThoughts??? I'm considering on putting a top cap to deflect hot air 900 away from the frustum. The beryllium gasket seal between the ceramic top plate and tuning chamber will leak hot air.Forcing hot air horizontally will eventually find an edge and rise. But..if it could be cooled enough before edge was reached...hmmmmThis WEB page gives formula to make estimate of the air velocity in the center of a convective flow : http://www.engineeringtoolbox.com/convective-air-flow-d_1006.htmlThe study of the sensitivity of the formula to its parameters can help to chose a design which reduces the velocity of the convective flow.6. Thinking I'll forgo the wrapping of the frustum in copper shavings for now and simply wrap it in reflective insulating lightweight foil that reflects back +95% of the thermal heat from the frustum. NASA would love this. http://www.geek.com/wp-content/uploads/2013/08/gold-1-590x330.jpgWould love to have input on these ideas.
Quote from: Mezzenile on 10/26/2015 07:55 amQuote from: rfmwguy on 10/26/2015 01:58 amQuote from: SeeShells on 10/26/2015 01:51 amThoughts??? I'm considering on putting a top cap to deflect hot air 900 away from the frustum. The beryllium gasket seal between the ceramic top plate and tuning chamber will leak hot air.Forcing hot air horizontally will eventually find an edge and rise. But..if it could be cooled enough before edge was reached...hmmmmThis WEB page gives formula to make estimate of the air velocity in the center of a convective flow : http://www.engineeringtoolbox.com/convective-air-flow-d_1006.htmlThe study of the sensitivity of the formula to its parameters can help to chose a design which reduces the velocity of the convective flow.I just love The Engineeringtoolbox.com. It's one of the top links on my computer. Remember when your desk and a close wall was covered in reference materials? I was up later than I should have been playing around with the idea of wrapping the frustum in copper shavings That lead me to conclude it 1. Would be a pain to do.2. Add weight3. Effect any IR videos looking for mode generation4. Give me maybe 30-60 seconds of run time with out thermal convection issues as the copper absorbed the heat from the frustum. 5. Wrap the frustum in copper shavings creating a 2-3 inch layer all around and over the top add a reflective insulating lightweight blanket. Now I have extended run times. 6. Thinking I'll forgo the wrapping of the frustum in copper shavings for now and simply wrap it in reflective insulating lightweight foil that reflects back +95% of the thermal heat from the frustum. NASA would love this. http://www.geek.com/wp-content/uploads/2013/08/gold-1-590x330.jpgWould love to have input on these ideas.
Quote from: SeeShells on 10/26/2015 12:33 pmQuote from: Mezzenile on 10/26/2015 07:55 amQuote from: rfmwguy on 10/26/2015 01:58 amQuote from: SeeShells on 10/26/2015 01:51 amThoughts??? I'm considering on putting a top cap to deflect hot air 900 away from the frustum. The beryllium gasket seal between the ceramic top plate and tuning chamber will leak hot air.Forcing hot air horizontally will eventually find an edge and rise. But..if it could be cooled enough before edge was reached...hmmmmThis WEB page gives formula to make estimate of the air velocity in the center of a convective flow : http://www.engineeringtoolbox.com/convective-air-flow-d_1006.htmlThe study of the sensitivity of the formula to its parameters can help to chose a design which reduces the velocity of the convective flow.6. Thinking I'll forgo the wrapping of the frustum in copper shavings for now and simply wrap it in reflective insulating lightweight foil that reflects back +95% of the thermal heat from the frustum. NASA would love this. http://www.geek.com/wp-content/uploads/2013/08/gold-1-590x330.jpgWould love to have input on these ideas.IR reflective duct tape might work, too - high temp env specs (so it can work in adverse HVAC environments). Used in a radiant heating project.For example - only good to 149 C, but still ...http://www.venturetape.com/pdfs/datasheets/1581A%20-%20TDS.pdfMight be easier to work with than bubble-wrap IR insulation - which certainly doesn't seem like it would take high contact heat all that well - I understand the IR reflective bubble wrap is a great heat transfer system with contact.
Well now...double coffee can, inner and outer walls. Inner wall covers magnetron. Fill area between inner and outer walls with copper shavings. I might have to steal borrow this idea myself https://www.etsy.com/listing/242690941/bright-shiny-copper-high-quality-very?ga_order=most_relevant&ga_search_type=all&ga_view_type=gallery&ga_search_query=copper%20shavings&ref=sr_gallery_220 bucks, not bad.
Quote from: SeeShells on 10/26/2015 02:23 pmWell now...double coffee can, inner and outer walls. Inner wall covers magnetron. Fill area between inner and outer walls with copper shavings. I might have to steal borrow this idea myself https://www.etsy.com/listing/242690941/bright-shiny-copper-high-quality-very?ga_order=most_relevant&ga_search_type=all&ga_view_type=gallery&ga_search_query=copper%20shavings&ref=sr_gallery_220 bucks, not bad.Try these guys: http://www.recycle.net/specs/gr050109.html?affilid=100029Google "copper turnings".
Out to the lab...Today I'm going to bond the sections of the cavity together using PC7 epoxy. This stuff is great, used it on a crack in the bottom of the hot tub. I had tried to fix this crack (cracks are bad for hot tubs) using about everything else I could find and nothing worked. PC7 sealed it up and is a hard as a rock and has lasted for over a year. Also going to work on the chicken wire cage for the frustum to contain the thermal heating effect.Shell
It is appropriate to be concerned about the force effects of heating .It is also appropriate to be concerned about reproducibility of the heat compensation system so that other Citizen Scientists can follow in your footsteps.When using a balance beam, seemingly one of the more simple methods to measure any effect in air, it seems that there have been proposed three general approaches:1) Minimize system heating in the design and attempt to remove residual heat effects, post processing.2) Capture the heat that is not removed by design, and attempt to remove residual effects post processing.3) Balance the heat effect with an equal and opposite source, removing residual effects post processing.So no matter what approach is used, residual effects will be removed by post processing.Of the above, 3) has been proposed but gained no traction. Why is that? A Google search on "common mode error rejection in physical systems" will return more information than can be absorbed, but a lot of good guidance, too. The common mode error compensation technique proposed previously is:Make two, not just one, frustum, near identical. Mount two frustums on opposite sides of the balance beam pivot.Run the system normally and remove residual effects by post processing.Questions. a) How expensive is it to make a second, near identical frustum?b) How hard is it to make and mount the second frustum safely on the test stand?c) How difficult will it be to take meaningful data with two 2 EM Drive effect sources?But the $64 question is, "How difficult would it be for others to accurately duplicate this system and use the same post processing techniques developed by predecessor DYI'ers?"It is important to step back out of the weeds for a moment and look at the overall objective. It is not simply to make a device for the fun of it and see if there is an effect.IMO, the objective of the efforts pulled together on this forum is to determine if there is in fact a REPRODUCIBLE EM Drive effect and then try to explain it. So using a reproducible system is crucial to that objective.
Quote from: Mezzenile on 10/26/2015 07:55 amQuote from: rfmwguy on 10/26/2015 01:58 amQuote from: SeeShells on 10/26/2015 01:51 amThoughts??? I'm considering on putting a top cap to deflect hot air 900 away from the frustum. The beryllium gasket seal between the ceramic top plate and tuning chamber will leak hot air.Forcing hot air horizontally will eventually find an edge and rise. But..if it could be cooled enough before edge was reached...hmmmmThis WEB page gives formula to make estimate of the air velocity in the center of a convective flow : http://www.engineeringtoolbox.com/convective-air-flow-d_1006.htmlThe study of the sensitivity of the formula to its parameters can help to chose a design which reduces the velocity of the convective flow.I just love The Engineeringtoolbox.com. It's one of the top links on my computer. Remember when your desk and a close wall was covered in reference materials? I was up later than I should have been playing around with the idea of wrapping the frustum in copper shavingsThat lead me to conclude it 1. Would be a pain to do.2. Add weight3. Effect any IR videos looking for mode generation4. Give me maybe 30-60 seconds of run time with out thermal convection issues as the copper absorbed the heat from the frustum. 5. Wrap the frustum in copper shavings creating a 2-3 inch layer all around and over the top add a reflective insulating lightweight blanket. Now I have extended run times. 6. Thinking I'll forgo the wrapping of the frustum in copper shavings for now and simply wrap it in reflective insulating lightweight foil that reflects back +95% of the thermal heat from the frustum. NASA would love this. http://www.geek.com/wp-content/uploads/2013/08/gold-1-590x330.jpgWould love to have input on these ideas.
Quote from: aero on 10/26/2015 03:41 pmIt is appropriate to be concerned about the force effects of heating .It is also appropriate to be concerned about reproducibility of the heat compensation system so that other Citizen Scientists can follow in your footsteps.When using a balance beam, seemingly one of the more simple methods to measure any effect in air, it seems that there have been proposed three general approaches:1) Minimize system heating in the design and attempt to remove residual heat effects, post processing.2) Capture the heat that is not removed by design, and attempt to remove residual effects post processing.3) Balance the heat effect with an equal and opposite source, removing residual effects post processing.So no matter what approach is used, residual effects will be removed by post processing.Of the above, 3) has been proposed but gained no traction. Why is that? A Google search on "common mode error rejection in physical systems" will return more information than can be absorbed, but a lot of good guidance, too. The common mode error compensation technique proposed previously is:Make two, not just one, frustum, near identical. Mount two frustums on opposite sides of the balance beam pivot.Run the system normally and remove residual effects by post processing.Questions. a) How expensive is it to make a second, near identical frustum?b) How hard is it to make and mount the second frustum safely on the test stand?c) How difficult will it be to take meaningful data with two 2 EM Drive effect sources?But the $64 question is, "How difficult would it be for others to accurately duplicate this system and use the same post processing techniques developed by predecessor DYI'ers?"It is important to step back out of the weeds for a moment and look at the overall objective. It is not simply to make a device for the fun of it and see if there is an effect.IMO, the objective of the efforts pulled together on this forum is to determine if there is in fact a REPRODUCIBLE EM Drive effect and then try to explain it. So using a reproducible system is crucial to that objective.
a) How expensive is it to make a second, near identical frustum? Several hundred $$ plus time.
[/b]b) How hard is it to make and mount the second frustum safely on the test stand? Not hard at all
c) How difficult will it be to take meaningful data with two 2 EM Drive effect sources? Are you suggesting 2 separate, powered magnetrons? If so, add some more $$ for a power supply, plus a controller to make them fire at the exact same time. Even with that, an imbalance will occur as air masses several feet apart are not identical, meaning there will still be residual thermals with one end versus the other. While its a good idea in theory, practical experience tell me that one could not guaranteed each side would heat and lift identically.
My take is ambient air perturbations are best left to only one source, the primary frustum. Delta displacement versus mag on/off times is extractable as has been demonstrated with earlier flight tests. As long as we're not in a vacuum, rotary or fulcrum is what we have to deal with in home lab testing.