Jan Ridders Stirling Bas underway

[dgjessing]

Not a lot to show yet, but I'm making some progress:

Obviously, I'm doing some things a bit different.

I didn't have a piece of brass big enough to do the flywheel so instead I've used some of this odd, very soft aluminum I've got laying around. Since aluminum is lighter than brass I figured leaving out the spokes would be prudent. It does have a brass hub pressed in :

I tried making the crank throws out of steel, but broke a 4/40 tap in one and switched to brass instead.

Cutting the Pyrex test tubes has proven to be fairly easy. I made a gizmo to hold my Dremel tool in the lathe tool post, and cut them with a little cut-off wheel (with the tube spinning in the chuck). I've experienced about an 80% success rate.

I'm taking a bit of work out of the central "hub" by making it somewhat less curvaceous than the plans show. I'm also doing away with the flats on the cylinder retention plates and the cold cylinder.

It's not going to be anywhere near as pretty as some other examples of the same posted here recently, but with any luck it will run. My Mom will certainly be impressed with it ;D

 

[steamin]

Looking great ! Your detail to surface finishing is awesome. Just a note on future tapping holes. Most drill charts we refer to suggest a drill that gives 75% thread contact. It holds true for small taps as well as large taps. I have always gone 1 to 2 sizes larger on the tap drill to eliminate what happened to you. This puts the thread contact in the 45% - 55% contact, which is more than enough for our model work. Looking forward to the finished product.

 

[dgjessing]

Progress!

steamin -good advise about tap drill sizes - I gotta remember to do that...

 

[shred]

looking good.. Mine has an aluminum flywheel as well-- I made the rim a little thicker to compensate and it's been fine with spokes, so don't worry if you decide to put some in.

 

[dgjessing]

Moving right along...

Once I get it running I'll treat myself to the brass trim pieces the plans show under the candle and the central pedestal ;D

I did the final curve on the pedestal with a wood turning gouge, with a blank turning tool held in the tool post as a rest. Worked surprisingly well!

Now onto the frame and all the little tiny bits.

 

[dgjessing]

More:

... the brass frame and the main shaft. I'm planning a bit more cleaning & polishing on the frame - will try to get rid of the solder fillet.

I did the 5mm steel main shaft with my Dremel tool as a tool post grinder in the lathe. I'm impressed - did a real nice job! Ya just have to take it slow & be patient. I predict that I'll make a new displacer shaft with the same technique by the time the thing starts running.

Friction in the main shaft/flywheel is certainly not going to be a problem - that sucker will spin for close to five minutes with a good flick of the wrist

 

[dgjessing]

Three more little parts to make! Pretty sure it's going to run - the power piston shuttles back & forth nicely when the flywheel is spun (thus moving the displacer). Just have to do the "little end" bearing thing for inside the piston, the wrist pin, and the connecting rod ;D

 

[b.lindsey]

Sounds like you are really close now Dave. Can't wait to see it running!!

Bill

 

[dgjessing]

It lives!

[ame]http://www.youtube.com/watch?v=ZPMqwaJ6n5U[/ame]

 

[lazylathe]

Awesome work!!!
I too would be very happy with it!!! ;D

Would be great if you could get it to run on a tea light candle, maybe it would not be so noisy if it ran a bit slower??

Excellent finish!!!

Andrew

 

[MatiR]

Nicely done!

Wow, it sure clips along - makes mine seem like a Model T ;D

Best regards, Mati

 

[dgjessing]

Progress!

[ame]http://www.youtube.com/watch?v=yfr8EuUM8rQ[/ame]

Made a new displacer shaft that's a much tighter fit, and the process involved getting a tiny bit of taper out of my lathe (adjusted the tail stock alignment). I also made a new displacer, because the original had cracked when it became unscrewed from the shaft whilst running... the new one is epoxied to the shaft's threads :. Also made a new displacer cylinder because the old one had a crack in it (that crack was there for yesterday's video - didn't seem to hurt anything, but made a new one anyway). Finally, I sealed the cold end parts with a thin film of silicone when assembling them.

I'm cheating a bit in that the tea candle it's running on has two wicks. It almost runs on a stock candle, but not quite. Must have some friction in there somewhere that I haven't found yet. I'll take it though ;D

Also need to do some balancing...

 

[dgjessing]

OK, another new displacer shaft, and a new bushing, and it's running on a proper single-wick tea candle ;D

I'll do a "finished project" thread soon