This is a 100mm diameter stator and diaphragm pair.
It took me a while to figure out how to make the PCB software generate gerbers and drill files to do this job since it is not really what the software is intended to do. I can get the diaphragm supports (spacers) in 0.6mm. The stator can be 1.6mm, this is cheapest. The stator can be covered with solder resist, except where there are pads. The mounting pad holes are M2, intended to accommodate Nylon bolts, the custom pads are just slightly larger than the holes which are M3. Total cost for 20 (5 sets) would be ~$110 delivered. $22 per set before postage. I still need to figure out some connection points on the edge.
These are not large capsules, but they fit into board dimensions which are available under the very best deal from China. I could go for 100*150mm rectangular or oval. This would increase the cost to $190 or $38 dollars a set.
This would relieve constructors of the need for a CNC mill, and access to different thicknesses of PCB, plus the stators could be resist-coated, one less process.
Edited by wakibaki - 7/8/14 at 8:01pm