MTFCA Forum

I saw this lathe post grinder in a museum last week and have a few questions I'm hoping someone can answer.
I'm not a machinist, so I was wondering what would the application be for a lathe post grinder with such a small diameter shank?
Also, is it oriented correctly for grinding/polishing? I was thinking the axis of the post grinder should be parallel to the lathe axis like the valve grinder in the last 2 pictures.

The shank appears to be missing a stone. The grinder can be turned and moved to different orientations relative to the work. That one may be suited for inside grinding.

Could be missing a cutter then it would used for cutting mica on armatures. Jim

Could be missing a cutter then it would used for cutting mica on armatures. You might want to re-cord it before use. Jim

As Tfan mentions, it's for undercutting mica in electric motor/generator armatures. It would have a tiny little saw blade in the end of its spindle.

That makes sense.
I was having a hard time picturing how that small diameter shaft and that tiny screw was going to hold a grinding stone.
It is positioned correctly for that application too.
Learned something new.
Thanks.

Hope this is OK Ken. I really like the shop you toured and your two pics of the HUGE engine valve in the lathe with another grinder are really neat!
Last night I watched a tube video of the same shop! About 10 minutes.
https://www.youtube.com/watch?v=cXDbH5pzagc
Not affiliated other than subscribing to the man's great channel.

Cool video Duane!
I spent most of the day at that museum and got to pet a sting ray there.

The other thing that caught my eye in the machine shop was the drums on the planer.
They reminded me of the drums in a model T transmission.
2 drums turn one way and the other 1 turns the other way.
The lever automatically slides the belt to the other drum at the end of the stroke.
This is the first planer that I have seen in a museum that was working.
The other ones I have seen were missing parts and hard to visualize exactly how it worked.

One last question, they refer to it as a planer.
Years ago, when I toured Giddings and Lewis, they called them shapers.
Is that like a soda vs pop thing?

Ken Lefeber wrote: ↑

Tue Sep 26, 2023 1:15 pm

One last question, they refer to it as a planer.
Years ago, when I toured Giddings and Lewis, they called them shapers.
Is that like a soda vs pop thing?
planer.JPG
planer drums.JPG

That's a planer. Shapers are a little different.

https://www.youtube.com/watch?v=7b81kWIhjPQ

Among other differences, a planer moves the workpiece under the cutter and a shaper moves the cutter over the workpiece.

Great video!
I learned something new again.
Thanks