'60' Sterling engine questions

[nautilus29]

What do you think of the gap? My displacer diameter is 1.8mm smaller then the glass I.D. Does that sound about right? I made that to what the print said.

 

[minh-thanh]

Nautilus29 !
If you do everything right according to the drawing, everything is ok
You just need to check:
1 / Friction - everything must move gently
2 / Air tight

 

[fcheslop]

The gap I was muttering on about is when the displacor is fully forward There should only be a small gap between it and the hot cap end.
As already mentioned try it on a spirit burner to get it running for a little while then switch back to a candle. I didnt need to do this but maybe I was just lucky
I no longer have the drawings so cannot check sizes
If theres very little friction then there must be an air leak either at the displacor bushing or the hot cap seal or maybe the power piston. Another killer is if the displacor is rubbing on the hot cap .
Dead space can have a marked effect on performance and I try to keep it to an absolute minimum
I reworked Rudys tractor reducing dead space and altering the mains and the performance is vastly improved as you can see here https://youtu.be/hpUQXHAX1Dw
Good luck its nearly there
cheers
frazer

 

[nautilus29]

I got it to run with a paraffin candle! Started up within seconds of lighting it. Hopefully the picture uploads. I may try to make a YouTube video of it starting up so you guys can see if you notice any problems.

 

[fcheslop]

Congratulations its always nice to have a runner
Whats next

 

[nautilus29]

https://youtu.be/OUZj_3eb44k here is a video I took.

 

[minh-thanh]

very nice, Congratulations !!:thumbup:

 

[ShopShoe]

That looks good. Great job with some nice bling.

It looks to be running very smoothly.

Thank You for posting.

--ShopShoe

 

[nautilus29]

Engine now runs on a cheapo tea candle. I will probs my do some more tinkering with it, but I'm happy to get it running ad it was intended!

I ended up pressing the flywheel off and giving myself a little more gap between the spindle and flywheel/crank assembly. I figured that would give it some sideways play if needed. I then took the joints off of the upper arm and lapped them again with lapping compound. This time I made sure I lapped with the arm right side up, up side down and flipped both directions. That really seemed to smooth it out. I think I was getting some drag from the center pivot point because when I flipped the arm upside down in that slot it bound up.