I won't be posting finished pictures just yet, on the off chance the recipients are on here (unlikely, but you never know), but the Jan Ridders Stirling Bas I made last year was very well received, so I made another Ridders design for a present this year. I modified the design just a little to fit materials and skills on-hand.
Here's some in-process photos. More tomorrow I think
Trepanning out a nice circular slot to fit the displacer cylinder. You can see my makeshift chuck spider behind (a chunk of stock of appropriate length, faced off and trimmed to fit the chuck through-hole behind)
Displacer rod parts. To avoid threading each end #2-56, they are tapped and short lengths of screw are glued in with Loctite 620
The design has the fork going into the bushing, so the fork has to be flush with the rod (you are probably better making the connecting rod a tiny bit short versus long). Chucked up in an ER-20 collet holder and stuck in the 3-jaw, this isn't ideal, but worked for the task at hand.
All done
Loctite #620.. as long as the parts are clean, once it sets, they're together forever unless you apply serious heat and torque. Most of this engine is stuck together with this. The crankshaft has taken a few whacks and drops and wobbles a bit, but is still tight.
The crankshaft jigged up, waiting for the 620 to set up.
Here's some in-process photos. More tomorrow I think
Trepanning out a nice circular slot to fit the displacer cylinder. You can see my makeshift chuck spider behind (a chunk of stock of appropriate length, faced off and trimmed to fit the chuck through-hole behind)
Displacer rod parts. To avoid threading each end #2-56, they are tapped and short lengths of screw are glued in with Loctite 620
The design has the fork going into the bushing, so the fork has to be flush with the rod (you are probably better making the connecting rod a tiny bit short versus long). Chucked up in an ER-20 collet holder and stuck in the 3-jaw, this isn't ideal, but worked for the task at hand.
All done
Loctite #620.. as long as the parts are clean, once it sets, they're together forever unless you apply serious heat and torque. Most of this engine is stuck together with this. The crankshaft has taken a few whacks and drops and wobbles a bit, but is still tight.
The crankshaft jigged up, waiting for the 620 to set up.