Spindle bearing woes

Hi Izzy,

Yes a lot of lathes use a total loss lubrication system. My Myford is the same, oil comes out all over the place, the chip tray is swimming in the stuff.

I can't offer anything further. Good luck with your repairs.
 
Well I spent most of the day trying different shims out in different spots. The front bearing has no shim at all now and the back bearing has about .015 in shims left. I got the side to side play down to 2.5 thou and the up and down play to a half thou or less but unfortunately the bearings and shaft are so badly worn that I can't get it any better than that. I'm afraid I'm going to have to get the caps skimmed and the bearings line bored as previously suggested :(
 
Here's how the bearings and shaft turned out after some light polishing and honing. I put the shims between the cap headstock is that correct or should it be between the bearing halves themselves? Seems like alot of the oil is coming out from the split in the bearings.IMG_20180929_144104.jpgIMG_20180929_144123.jpgIMG_20180929_144225.jpgIMG_20180929_144246.jpgIMG_20180929_164344.jpg
 
The shims go between the saddle and cap. What's going on in that last photo? Is that a shim? If it is, I'd make sure to have crazy glue and plenty of sterile suture and gauze really close by. It might be in backwards.

(from mobile)
 
Hi Izzy,

Now that you have removed material from both the spindle and the bearings, you are going to have to get the cap and maybe the bearing mating surfaces machined to get back the clearance adjustment ! No shims means that you have got to the limit of how tight you can now get the fit.

I would suggest that 10 thou off the cap faces and a few thou off the bearing might get you back to a sane state. Then add shims in 1 thou steps from 10 down.

The oil escaping from between the bearing split faces is because of the inevitable gap there.
 
@pontiac428 i had pulled the shims out to show where i was putting them. im no machine rebuilder by anymeans i just do this as a hobby so i wanted to make sure im doing things right. on a side note im assuming saddle=headstock? just to make sure we're on the same page here.
@BaronJ the front bearing spun without shims before i did any honing or polishing its the back bearing that would bind up without any shims. im afraid im going to have to get the caps skimmed and line bored as both you and pontiac have suggested i just need to finish this part before sending my lathe off for repairs. do you reckon i could save a bit of money and skim the caps myself on the bridgeport then just have someone line bore the bearings and grind the shaft?
 
Also note that as the spindle moves up or down in relation to the headstock, it also moves in relation to the tailstock. The tailstock center may end up too high and need work also.
 
yea im not looking forward to the tailstock adjustment after doing all this but the spindle is #1 priority. assuming i get the caps skimmed and the bearing re-bored ill probably have to lower the tailstock correct? how would i even go about doing that?
 
Hi Izzy, Guys,

OK Izzy, do it the hard way !

Use some 600-800 grit emery paper on a good flat surface, like a piece of plate glass. Stick the emery paper down with double sided tape at the top and bottom edges. Use oil to act as a lubricant between the work and emery paper. All the oil is intended to do is to stop the emery paper surface from clogging up. The oil will contain most if not all the material removed. You must clean the caps/bearings thoroughly before testing. The thing you don't want is transferring abrasive particles to the lathe spindle.

Rub the bearing cap on the emery paper, wipe it clean test with the bearing in place, and do it again, until you have a fit that you are happy with.
Do the front cap and bearing first. Leave the rear cap off until you have done the front one.

Then leave the front cap off until you have set the rear one.

At this point you will have a known set of shims for both front and back bearings. Now you can start to set the spindle clearances as you want them.
Either adding shims or rubbing off material from the caps.

The headstock is the part you are working on ! The saddle is the part that moves up and down the lathe bed.
 
When I spoke of the saddle and cap, I was referring to the two halves that enclose the bearing. The portion webbed into the headstock is the saddle, and the bearing cap is the cap. A lathe has its own saddle/carrier, but the conversation was about bearings so I didn't think clarification is necessary. Sorry for muddying the waters.

Sent from my HTC U11 using Tapatalk
 
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