Fixing Lathe Run-Out - Fixed!

[crokett]

Ok... long story but after replacing the head stock belt on a Delta 46-465, which as per the directions involved me whacking the spindle in a vain attempt to get it moved out of one side of the head stock to replace the belt, I put the chuck on the lathe last night and there was a noticeable wobble. Tonight I put a dial indicator on the headstock spindle and measured ~ 12 1/1000ths out of true. I can't swear it was always like this since I've mostly used the chuck at turning class. Turning between centers seems to be ok - a trued cylinder tonight didn't seem to have much runout. but I am certainly willing to concede I screwed it up. Is there a way to fix this? My Google-Fu is not strong tonight on finding suggestions for fixing it. Am I strong enough to have bent the spindle while it is still inside the stepped pulley? I used both a rubber mallet and a framing hammer with a wood block.


Learned today that the chuck could be installed on the outboard side of the lathe also, so put it there and no wobble. Next I put a 1" 8 tpi nut on the inboard side spaced off the spindle nut then jammed the chuck against that, no wobble. Next I took off the spindle nut and noticed a bit of munging around where a wrench slipped at one of the points. Turned it around, put the chuck against the wrong side, no wobble. filed down the munge, put the spindle nut back on and no wobble. :gar-Bi

 

[crokett]

Re: Fixing Lathe Run-Out

I was thinking about this more in the shower. I think the problem is the spindle lock nut, not the spindle. with runout at 15 1/1000ths that is 1.5 1/100ths. The chuck is wobbling a lot more than that, at least 1/8th out, probably more. 1/16th inches is around 6 1/100ths. So I'd have to have 6 times the runout to even get to something I could start to see.

 

[CaptnA]

Re: Fixing Lathe Run-Out

when I replaced the drive belt on mine, I wound up replacing the bearings in the head stock.
Think they didn't like my persuasion techniques.

 

[boxxmaker]

Re: Fixing Lathe Run-Out

I wouldn't think that you could have bent the spindle,but when folks start doing the whack attack on bearings,they seem to get upset, :kamahlituas all you have to do is hit the spingle at an angle and that can bend the bearing housing,so like said I thinks that may be the culprit :widea:

 

[crokett]

Re: Fixing Lathe Run-Out

Yeah, thought of that too...

I did find one reference this AM to a guy with a similar delta lathe and the same problem. He replaced the spindle nut. I also picked up some nuts today and will put a piece of ply between them and see what it does. It won't be backed up against the spindle nut like the chuck is. I am also going to talk to my instructor tonight.