This is a 3D model of the "Shawyer Demo". I built it as close as I can figure that it has to be and examining the several photographs that have been shared here. The dimensions are from published values.

rfFrequency=2.45*10^9;

cavityLength=0.345;

bigDiameter=0.28;

smallDiameter= 0.128853

power = 421 to 1200

Q = 45000

(measured force = 102.30 milliNewtons only reported for 421 watts, 243 milliNewtons/kW )

measured ForcePerPowerInput = 80 to 243

Force/PowerInput of a Photon Rocket =0.003337

measured ForcePerPowerInput to the one of a photon rocket =23,980 to 72,830

While this is a crude SketchUp model if anyone wants the model I'm happy to share it.

That is a really impressive job!

I have recalculated the small diameter, using Shawyer's paper http://www.emdrive.com/IAC-08-C4-4-7.pdf, see page 7, where Shawyer states

The engine was built to operate at 2.45 GHz, with** a design factor of 0.844** and has measured Q of 45,000 for an **overall diameter of 280 mm**.

(Unfortunately, Shawyer does not provide the small diameter or the cavity length in his paper)

I have used this information

bigDiameter = 0.28 m;

f = 2.45*10^9 Hz;

cst = 1.7062895542683174;

cM = 299705000 m/s (speed of light in air);

Design Factor = 0.844,

and inverted the equation for the Design Factor (see: http://forum.nasaspaceflight.com/index.php?topic=36313.msg1374110#msg1374110 ) to obtain the following correct dimension:

**small diameter = 0.09613 m**

Therefore, the dimensions should be corrected as follows

rfFrequency=2.45*10^9;

cavityLength=0.345; (ESTIMATED from Photographs)

bigDiameter=0.28 m; (provided by Shawyer)

smallDiameter= 0.09613 m; (obtained from the Design Factor, bigDiameter and frequency provided by Shawyer)

I believe the dimensions I used were published and copied here to the forum some time ago - I don't recall the source and I'm sure it would take awhile to find the original post - here are the dimensions as posted though (I had copied to a file)

Notice that the force per power input reported by Fearn, Zachar, Woodward & Wanser is several orders of magnitude lower than the "EM drives". Actually it is barely (3.5 times higher) more than the force per power input of a photon rocket:

reported measurement ForcePerPowerInput (milliNewtons/kW)

(* Cannae Superconducting *) 761.9 to 952.4

(* Shawyer Demo *) 80 to 243

(* Shawyer Experimental *) 18.82

(* Brady c TE mode *) 21.31

(* Brady a TM mode*) 5.396

(* Brady b TM mode*) 3.000

(*Fearn, Zachar, Woodward & Wanser*) 0.01176

lengths in meter

rfFrequency in 1/second (microwave frequency during test)

power in watts

force in milliNewtons

force per PowerInput in milliNewtons/kW

c= 299705000 m/s (speed of light in air)

c= 299792458 m/s (speed of light in vacuum) (for Cannae Superconducting)

(the difference between c in air compared to c in vacuum is negligible)

Note: SmallDiameter for Shawyer's EM Drives obtained from his reported ShawyerDesignFactor .

Force/PowerInput of a Photon Rocket = 1 / c

(* Cannae Superconducting *)

rfFrequency = 1.047*10^9;

cavityLength = 0.01+0.004+0.006+0.01 = 0.03;

bigDiameter =(22.86-2*(0.00430)) = 0.220;

smallDiameter = bigDiameter-2*0.01=0.200;

power = 10.5

Q = 1.1*(10^7)

measured force = 8 to 10

measured ForcePerPowerInput = 761.9 to 952.4

Force/PowerInput of a Photon Rocket =0.003336

measured ForcePerPowerInput to the one of a photon rocket = 228,400 to 285,500

(* Shawyer Experimental *)

rfFrequency=2.45*10^9;

cavityLength=0.156;

bigDiameter=0.16;

smallDiameter=0.127546;

power = 850

Q = 5900

measured force = 16

measured ForcePerPowerInput = 18.82

Force/PowerInput of a Photon Rocket =0.003337

measured ForcePerPowerInput to the one of a photon rocket =5,640

(* Shawyer Demo *)

rfFrequency=2.45*10^9;

cavityLength=0.345;

bigDiameter=0.28;

smallDiameter= 0.128853

power = 421 to 1200

Q = 45000

(measured force = 102.30 milliNewtons only reported for 421 watts, 243 milliNewtons/kW )

measured ForcePerPowerInput = 80 to 243

Force/PowerInput of a Photon Rocket =0.003337

measured ForcePerPowerInput to the one of a photon rocket =23,980 to 72,830

All Brady cases have the following dimensions:

cavityLength=0.332;

bigDiameter=0.397;

smallDiameter=0.244;

(* Brady a TM mode*)

rfFrequency=1.9326*10^9;

power = 16.9

Q = 7320

measured force = 0.0912

measured ForcePerPowerInput = 5.396

Force/PowerInput of a Photon Rocket =0.003337

measured ForcePerPowerInput to the one of a photon rocket =1,617.2

(* Brady b TM mode*)

rfFrequency=1.9367*10^9;

power = 16.7

Q = 18100

measured force = 0.0501

measured ForcePerPowerInput = 3.000

Force/PowerInput of a Photon Rocket =0.003337

measured ForcePerPowerInput to the one of a photon rocket =899.12

(* Brady c TE mode *)

rfFrequency = 1.8804*10^9;

power = 2.6

Q = 22000

measured force = 0.05541

measured ForcePerPowerInput = 21.31

Force/PowerInput of a Photon Rocket =0.003337

measured ForcePerPowerInput to the one of a photon rocket =6,386.7

(* Fearn, Zachar, Woodward & Wanser*)

rfFrequency = 39,300;

power = 170

measured force = 0.002

measured ForcePerPowerInput = 0.01176

Force/PowerInput of a Photon Rocket =0.003337

measured ForcePerPowerInput to the one of a photon rocket = 3.526

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As it is my intention to duplicate Shawyer's model first I need to go with his dimensions - though now I want to verify where these dimensions came from.