Romanian electrical engineer Iulian Berca began EmDrive experiments in May, 2015. After the invention of the EM Drive by Roger Shawyer, Iulan Berca was the first independent engineer to fabricate a working EmDrive and successfully record force from the device.
Iulian Berca built a copper frustum with dimensions similar to the device tested by NASA Eagleworks in 2014 and 2015. He powered this device with a 800-1200W magnetron directly inserted into the frustum. He originally tested this in a horizontal orientation suspended from fishing line, hoping to visually detect thrust. He then changed his testing setup to hang the frustum from a balance arm resting on a microgram scale. Thrust was then detected based on changes in the weight measured by the scale.
Berca's first two tests were inconclusive, as thrust was not visually detectable. In test #3, thrust was detected with the frustum's direction of motion oriented up (small end up). In test 3.1 he reversed the orientation (small end down) and again detected thrust.
On the forum a number of possible error sources have been mentioned, that could affect these results. They include:
- Material ablation/ejection
- Thermal convection outside of the cavity from heated walls
- The force of the spring on Iulian's torque arm
- Accumulating errors in the digital scale from rf exposure
- Thermal buckling causing a shift in the COM
- Forces between wires connected to the frustum and wires that are not
Also see Possible_Error_Sources for general EM Drive discussion of error sources, not specific to this particular setup.
Berca is currently modifying the frustum to include an adjustable plate on the small end similar to Shawyer's demonstration unit (though without the motor; adjustments will be made manually). He will then retest multiple times to find what length provides optimal thrust.