The More I Learn The Worse Things Seem To Be. Spindle Binding.

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jbmauser

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I watched a video online and saw how to check for play in the spindle of my SB 9C lathe. I put a bar in the chuck end and got over 4 thou of movement. I put a wrench on the the single bolt on the chuck side to remove it and pull the shims as instructed. The bolt was not very tight so I first torqued it down snugly and checked it again and the play closed to 2 thou but the spindle had a little resistance when turned by hand. I backed it off a tad and it spins by hand. But not free wheeling. I moved to the tail which runs a lot of oil and I found that bolt as not snugged down hard. I took a reading of over 4 thou and snugged it down and it binds on a high spot like the shaft is egg shaped backed it off and it spins free. I have ordered a needle bearing and two hard washers as recommended to replace the fiber bearing. This should cut down on the oil leaking.

I know it is more than likely the headstock opening that is egg shaped and not the spindle but the fact remains it only binds on a small area as the spindle is turned by hand. So I backed off both front and back bolts till the spindle spins freely with a bit of overtravel when spun by home. When the needle bearing comes in it may hopefully remedy the oil leakage. I do not work in high tolerances (yet) so it is what it is.
 
Pull the spindle and go looking for problems. Measure the spindle at multiple points around the dia and see if you have high spot/s. Alternatively, if you didnt know you had a problem before checking, and it wasnt causing you problems, is it something you dont need to be concerned about?

Cheers Phil
 
You are aware that plain spindle bearings run on an oil/surface interface, indicate it with the spindle warm and running, it is not bad practice to place an indicator on a part under power regardless of what some people will tell you.

It is difficult to measure a dynamic system at rest, measure it when it is running.

Good luck
 
The spindle bearings on the 9" South Bend Lathes are notorious for galling from improper lubrication in it's lifetime. I've seen a few over the years that were very bad, some slightly scored. Like 12bolts said, need to pull the spindle out and see what is going on. Very good chance some has already been into it and did not re-assemble properly. It is easy to screw up. Most people don't know the proper way to reinstall the spring loaded felt pads in the lubrication pocket. The other thing is getting the bull gear installed or uninstalled properly without damaging the journals in the housing.
 
4gsr, I posted this question on the South Bend forum as well, I posted pics of my original spindle because someone suggested that my spindle may be bent. I will pull the spindle today and try and check it for a bend. I may just put the original spindle in and see how that measures up. Also, my lathe is a top oiler with a simple press in ribbon felt that was not a problem with reinsertion.

I apologize for posting this in two locations but I had intended on posting it on the South Bend forum but I returned to this form without thinking as I have been posting and lurking here because of all of the great info I have received.
 
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