Shawyer made an explanation years ago about how the thruster would develop less and less thrust the faster it was going, but the mechanism made no sense, and it still proposed to violate conservation, and the whole notion of velocity changing thrust is again, a violation of relativity. Velocity relative to what exactly? Made no sense and that was just before they cut his funding in Great Britain, IIRC.
To explain the impulse part of the response,I need to have an independent estimate of the copper thickness in these devices.could anyone please provide a guesstimate or a range for what the thickness of the copper in these EM drives maybe ?
I'm trying to scrap the data from the graphs of anomalous thrust... into a clean data format for the sheer enjoyment of all. Problem with the vertical scale : page 15 fig. 19 we see that the calibration pulses of purported 30µN (29.1 precisely) span very close to 1 µm deviation on the vertical scale. Page 16 fig. upper left picture is more like 1.6 or 1.7 µm for the same purported 30µN, lower 2 pictures almost exactly 2 µm (always for 30µm or so). Page 17 fig.21 between 1.8 and 1.9 µN (to the naked eye). Page 18 fig. 22 no explicit vertical scale in µm.How comes ? Am I to trust the cal. pulses amplitudes as an (approximate) way to scale µm to µN, therefore discarding the vertical left axis scale µm readings as irrelevant display feature (but those values otherwise look perfectly sensible as to the rest position) ? Is it possible that "variations" in stiffness of flexure bearings could change that much the µN/µm ratio ?? Could it be that the calibration pulses are, well, not that much calibrated ? Any indication in the reported that I missed that could explain this huge disparity ? What should be the torque/angle spring constant of the flexure bearings ? Or the calibration gizmo where moved along the beam's axis and that changed the torque at constant force ?
Displacement of the pendulum arm is measured via a Linear Displacement Sensor (LDS). The primary LDS components consist of a combined laser and optical sensor on the fixed structure and a mirror on the pendulum arm. The LDS laser emits a beam which is reflected by the mirror and subsequently detected by the optical sensor. The LDS software calculates the displacement (down to the sub-micrometer level) based upon the beam reflection time. Prior to a test run data take, the LDS is positioned to a known displacement datum (usually 500 micrometers) via mechanical adjustments to its mounting platform. Gross adjustments are performed via set screws. Fine adjustments are performed using manually-operated calibrated screw mechanisms and a remotely controlled motorized mechanism that can be operated with the chamber door closed and the chamber at vacuum. The remote adjustment capability is necessary since the LDS datum will change whenever a change to the test facility environment affects the roll-out table or the chamber – e.g., whenever the chamber door is closed or latched and whenever the chamber is evacuated. Once the LDS displacement is adjusted in the final test environment, further adjustment between test run data takes is usually not required.Immediately prior to a test run data take, the displacement/force relationship is verified by inducing a known force onto the pendulum arm and measuring the displacement. This is done via the electrostatic fins calibration mechanism. This mechanism uses two sets of aluminum fins, one set on the fixed structure and one set on the pendulum arm. The fins overlap without touching. A calibration voltage is applied to the fixed structure fins, which induces a force upon the pendulum arm fins and an associated displacement that is measured by the LDS. The electrostatic fins design provides a constant force over a reasonably large range (between 30-70% overlap), so adjustments to the calibration mechanism between test run data takes and even between test article reconfiguration are usually not required. Calibration of the overlap/force relationship was accomplished using a Scientech SA 210 precision weighing balance (resolution to one micronewton).
In regards to force calibration we used a set of NIST traceable, pre-calibrated meshed electrostatic fins that provided a constant attractive force between the fin pair for a given applied calibration voltage over a 25% to 75% meshed fins range. This feature allows us to generate the same calibration force independent of the loading of the torque pendulum's C-flex torsional bearings or how much the fin set is meshed within the noted fin mesh range.
Quote from: Rodal on 10/31/2014 06:08 pmTo explain the impulse part of the response,I need to have an independent estimate of the copper thickness in these devices.could anyone please provide a guesstimate or a range for what the thickness of the copper in these EM drives maybe ?I am also interested in the thickness of the NASA test article. Shawyer and the Chinese I don't care about because of my lack of confidence in their reporting. It is important to my evanescent wave coupling hypothesis; in the quest for yet another plausible artifact to explain away reports of thrust from an empty copper can under high power. I've been getting indications and warnings of 1/8" thickness, but I cannot confirm with high confidence.
Quote from: Mulletron on 10/31/2014 08:26 pmQuote from: Rodal on 10/31/2014 06:08 pmTo explain the impulse part of the response,I need to have an independent estimate of the copper thickness in these devices.could anyone please provide a guesstimate or a range for what the thickness of the copper in these EM drives maybe ?I am also interested in the thickness of the NASA test article. Shawyer and the Chinese I don't care about because of my lack of confidence in their reporting. It is important to my evanescent wave coupling hypothesis; in the quest for yet another plausible artifact to explain away reports of thrust from an empty copper can under high power. I've been getting indications and warnings of 1/8" thickness, but I cannot confirm with high confidence.I expect the cavities were made of some commonly available copper sheet. I doubt that Eagleworks did anything more difficult than go to the hardware store and buy a sheet of copper. Here is a web site that sells copper sheet. Look at the choices and take your pick. Or find your own favorite copper sheet retailer. Or call your local hardware store and ask them what thicknesses they have in stock. But from looking at the photo I can't tell, the resolution isn't good enough.
Sorry for asking, but -as the discussion is getting very technical- could someone of you make a quick update for the non-physicists among us (like myself)? is there any tangible progress, or has the device been demistified once for all?thanks!
Quote from: aero on 10/31/2014 08:42 pmQuote from: Mulletron on 10/31/2014 08:26 pmQuote from: Rodal on 10/31/2014 06:08 pmTo explain the impulse part of the response,I need to have an independent estimate of the copper thickness in these devices.could anyone please provide a guesstimate or a range for what the thickness of the copper in these EM drives maybe ?I am also interested in the thickness of the NASA test article. Shawyer and the Chinese I don't care about because of my lack of confidence in their reporting. It is important to my evanescent wave coupling hypothesis; in the quest for yet another plausible artifact to explain away reports of thrust from an empty copper can under high power. I've been getting indications and warnings of 1/8" thickness, but I cannot confirm with high confidence.I expect the cavities were made of some commonly available copper sheet. I doubt that Eagleworks did anything more difficult than go to the hardware store and buy a sheet of copper. Here is a web site that sells copper sheet. Look at the choices and take your pick. Or find your own favorite copper sheet retailer. Or call your local hardware store and ask them what thicknesses they have in stock. But from looking at the photo I can't tell, the resolution isn't good enough.aero, although you wrote "Here is a web site that sells copper sheet" I do not see any web site information in your message. Could you please indicate what website you have in mind?Mlltrn suggested copper 1/8" thick, that is thicker than the copper sheet readily available at my local hardware store. Do you think that they likely used thinner copper than 1/8? (I think that 1/16" would have been easier to work with. All these sheets are already smooth and shiny)
.... Well, I lost the site I was looking at earlier. Here's one that includes a thickness guide for choosing copper for a project. That might help but you'll have to convert the thickness to metric.http://basiccopper.com/copper-sheet--rolls.html
...A proper spectrum analysis would be more elegant but since I don't have those tools at hand I went through crest detection. ...
First attempt to scrap the data and infer some parameter of the balance. From the top picture of figure 19 only, median natural period of oscillation would be 4.8s. ...
The natural oscillation period of the pendulum arm when loaded with the RF amplifier, its RF plumbing and the test article was around 4.5 seconds.
Quote from: aero on 10/31/2014 11:01 pm.... Well, I lost the site I was looking at earlier. Here's one that includes a thickness guide for choosing copper for a project. That might help but you'll have to convert the thickness to metric.http://basiccopper.com/copper-sheet--rolls.htmlThey show at the site you included thicknesses that range between 0.001 to 0.022 inches, while Mlltrn suggested 0.125 inches (125 times to 6 times thicker). In other words, you think that NASA used much thinner copper than him
Quote from: Rodal on 10/31/2014 11:15 pmQuote from: aero on 10/31/2014 11:01 pm.... Well, I lost the site I was looking at earlier. Here's one that includes a thickness guide for choosing copper for a project. That might help but you'll have to convert the thickness to metric.http://basiccopper.com/copper-sheet--rolls.htmlThey show at the site you included thicknesses that range between 0.001 to 0.022 inches, while Mlltrn suggested 0.125 inches (125 times to 6 times thicker). In other words, you think that NASA used much thinner copper than himSorry, I looked some more. The site I lost sold 1/8 copper sheet. But copper sheet is available from film to 1 inch plate so looking for a common thickness of sheet isn't going to help us. I would guess it is 1/8-th inch sheet but I've nothing to base that on except having seen it around here and there and it looks like 1/8-th inch. Of course it could be 1/16-th inch sheet and I wouldn't know the difference. For the application it needs to be thin enough to roll into a cone and crimp right angle bends at both ends to attach the end plates. Then it also needs to be thick enough to hold its shape or pop back into shape when/if it is dented. Will 1/16 inch verses 1/8 inch make a difference in your calculations?Looking at my ruler, I'd go with the thinner sheet. One-eighth inch is 0.3175 cm and we might be able to see that on the photos.Add: In fact, the photo resolution is 0.11 cm/pixel, so 1/8 inch would be about 3 pixels which we would certainly be able to see. Is there a rule about resolution of a photo? We might even see 1/16 inch, at 1.5 pixels.