Talk about a total fail...

Not sure if the dremel would be more accurate or not.
Coarsest stone you can get and the highest speed and very light touch might work.
You can use a pencil to mark the inside of the collet instead of dykem to avoid loading the small stone up.
 
The Dremel is all I have, I'll give it a go and see how it works. Anything is an improvement. And I left enough meat on the collet to do redo if I screw up. I have about an inch I could potentially take off before I get too close to the spindle threads. Not that I'd need to take nearly that off...
 
The Dremel is not very rigid. Make sure you are only cutting on the side you want to. That takes very light cuts with a flexible tool shank.
 
You mean a 3/32" shaft won't take abom strength?!?
I'd only be kissing the surface, just enough to smooth, really. I'll try, if it doesn't work, then I'm back to square one.
 
I ground it with the Dremel. Not an amazing set up, but it was rigid. I maybe took off .001. That's all I needed. It took off the tool marks and lines. I put a 3/8" collet with a newer end mill and ran the lathe with the DTI. The needle was swinging alllllll over the place. Annoyed, I shut the lathe off and spun by hand. The needle barely moved...
The vibration from the crummy 1hp motor (with blown bearings) is transfering through everything into the indicator holder into the DTI. If I ran the lathe, then shut it off and let the spindle spin down, the most run out was less than .0005" it wiggled between the two .0005 lines.
I think I'd call that a successful rebuild, and the elephant in the room is the need to swap out this motor for the 2hp sitting under my bench... Would be real nice to put a VFD on here and do away with the pulleys... They're just noisy anyways.

IMG_20171102_232823.jpg
 
Sounds like a WIN!!!
.0005 TIR.....better than most you can buy..Excellent!
That will be a very handy tool to have.
 
The vibration from the crummy 1hp motor (with blown bearings) is transfering through everything into the indicator holder into the DTI. .........and the elephant in the room is the need to swap out this motor for the 2hp sitting under my bench... Would be real nice to put a VFD on here and do away with the pulleys... They're just noisy anyways.

Wow! 0.0005" is a great result. Congrats!

You might also consider a DC treadmill motor conversion.
You can often find them free if your willing to move them.

-brino
 
I saw a write-up that showed that tightening tecnique had a measurable influence on runout it was in Model Engineers Workshop magazine if I recall correctly.
 
I did notice that. I noticed a considerable difference between snuggled and torqued. I've also read before certain ER sizes require X torque. Somewhere in the 100 inch or foot pounds. Don't remember which or if that's accurate.
 
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