Not quite a micro micro turbine, but here is my latest homebuilt., since we are on the subject..... 73mm compressor. Roughly based on KJ, Wren style construction. Photo on test stand shows first test run, with prototype ECU, so far so good, although did have some turbine to shroud rubbing on cooldown. I have no idea what the thrust will be on this one, should be quite low, with hopefully low fuel consumption with a rather small throughput, hi pressure ratio compressor. Engine 4.75 inches in diameter, came out a little heavy. Built on all manual mill and lathe, no CNC whatsoever. Runs on $4.00 bearings, although I have a great source for gr 5 ceramic balls(they are modified for full 11 ball compliment). Hand ground Inco 718 turbine wheel(dont' ever want to do that again), believe it or not, even the diffuser was cut on a manual mill, with a lot of thinking and fixturing, did I mention thinking????
Andy

Oh yeah, runs on Diesel too!

{EDIT} I feel like I am postwhoring, sorry, I just get so excited when I see others that are homebuilding, as there are not many of us. In no way do I intent to one up anyone, I just thought I would share my latest work in a relevant post.

AP