I had very little time to work on the device but finally made some progress last week.
2 fundamental problems were identified.
The engine is mounted to the frame via springs. As vibration is important to the entire device, we realized that this connection via the springs needed to be firm & tight. That was fixed.
The second problem is with the hot cap & displacer. The gap between the two should be small. However, our gap is far too small. The way we fabricated the devices was also poor. With a bit of online shopping, we discovered we can buy ideal cans off the shelf to use as the hot cap & displacer.
Now, we just have to wait for the parts to arrive. We will try to do a bit of work on the magnet assy to go on top of the device while we wait for the parts. Fixing these 2 basic things should tell us if the hard things we make like the planar spring & beryllium copper plate are good or bad.
This thing is simultaneously amazingly simple & deeply complex. I will be very happy if we ever get it to function.
This note is just to say the project is ongoing