Two steps forward, one step back.
I spent more time working on the 3D printable liquid piston Stirling engine tonight and implemented several improvements. The model self-destructed, but I still learned some things. What worked well? Sealant elimination: Using a formed TPU gasket of sealant looks promising. The gasket, in purple, is printed in SainSmart TPU. It is a separate component, not a multi-material print. The filament fed well through my MMU so I may attempt a Multi-material print with it in the future. I threaded two stainless steel M3 fasteners into the liquid chamber as electrical feedthroughs. This worked very well. The resistor/heater leads are held in place with a second nut on the same fastener. As a side effect, this stopped the resistor from flopping around under the pressure of the test leads. What didn't work? The holes printed significantly undersize. This is probably a modeling error. Also, there isn't enough material around the holes for screwing on the cover. I could see the hous