LTD Stirling

[Cogsy]

Hah! I put it in an electric skillet set to 350F (probably way hotter than necessary, and only as I write this do the words "temper" and "draw" zip through my brain), and it popped right out. Next time I won't get it so warm, if there even needs to be a next time.

Although it's unlikely to make much of a difference on a tiny bearing like that, most bearings are only dimensionally stable to around 110 Celsius (230 ish Fahrenheit) and shouldn't be heated above that or they may permanently deform. SKF 'Explorer' bearings can handle a bit more (about 150 C from memory) but in general you don't want your precision bearings getting too warm.

 

[Tim Wescott]

After I did the above, I decided that I wanted the groove to fit entirely inside my 1/2" square bar. This entailed not just making the diameter smaller, but reworking my tool because it was not clearing the 0.44" OD of the trepan. But the test cut came out pretty good; I feel confident in doing it for real.

One lesson I think I should learn here is "don't take pictures of your work under a microscope". Clearly, it isn't sticking.

 

[Tim Wescott]

Gaah! I just mucked up my bearing block! I should have used blocks to keep the chuck from digging into the ends. Next one I'll do the mount ring first (when the ends are solid!) then bore it out and do the bearing holes. Which I have to get right again, after sweating bullets the first time over them.