This is not going to be a productive night in the shop. The girls have left me for the evening and I have to deal with the little extortionists at the door. Before I gave up and went upstairs, I was trying to figure out how to get the spindle lock assembly off. Presently the knob can be pushed in a small amount, but not far enough to slide the dog into the spindle. Any hints?
Kevin Gallimore
Thanks, I found the setscrew hole under five generations of paint. Pulled the bolt out to find the reason it does not engage is that the holes in the bolt slide and spindle drive sleeve don't line up by about ~.075. I can find a single setscrew in the spindle drive sleeve. My guess at the moment is that the fix is to loosen the setscrew and tap the spindle drive sleeve into position. Is there a better procedure?
Kevin Gallimore
Then something's wrong. That spindle sleeve is in compression between the rear bearing and front bearing races, and transfers the preload from the clamp nut to the front bearings. Messing with the preload is a big no-no if you have good bearings. Removing the pulley screw would only allow you to shift the pulley and possibly pull the spindle, which wouldn't help your alignment issue.
I'd check the spindle front cap. That's the only place you could adjust the spindle front to back location in the column, probably with shims.
One other uglier possibility is that someone backed off the clamp nut on the back of the spindle, and the spindle shifted. If that's the case, google "Gunner Hardinge spindle" for tips on proper procedure for replacing the bearings, etc.
Oh, and if you need the manual and drawings, look in the files section of the Yahoo Hardinge-Mill group.
Good luck.
Pete Keillor
Hmm. A puzzler. It's been some time since I had the spindle out of my UM but I'm here perusing the exploded diagram. Looks like the setscrew holds the three belt pulley to the spindle sleeve, or maybe it holds it right to the spindle itself. Can't tell from the diagram.
The sleeve is indeed under compression from the rear clamp nut. Further it looks like the sleeve itself has the sheave for the power feed belt cut into its surface so there's no way that somebody could have put it on the spindle backwards. (might be worth a double check, to be sure that there's no V-belt groove on the sleeve, near the triple pulley section. I think that one can put that sleeve on the wrong way round...)
I would be interested to know which way the lock pin hole has been offset - is the hole in the sleeve too close to the front, or to the rear of the machine?
If for some reason somebody has put an incorrect part in the machine, the spindle could be easily removed - the sleeve has to come off to do this - and two new lockpin holes could be machined into it, at 90 degrees to the other ones.
But I don't think Hardinge ever made that dimension (the location of the locking pin) as a variable in their various designs. That's the puzzler.
I would tend to dismiss out of hand the thought that the spindle has been shifted. 0.075 inch of offset would make the nose of the spindle behave wrong in some fashion.
Jim
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