What's new
What's new

How to repair (really) badly scored/galled headstock spindle bearings?

Joined
Apr 1, 2020
Location
Pretoria, Gauteng, South Africa
Hi guys, I'm new to this forum, new to forums in general and new to lathes, so please forgive any improprieties on my part.

I have a used 1937 9" 'Workshop' type 415Y – serial number 78661 (SB renamed these lathes to type 'C' later on). Bought it in March 2020 (pre covid lockdown) and have not used it yet. I am currently attempting to restore it. It has a very badly galled headstock spindle and bearings. The spindle is the 1 1/2" 8-thread one. These lathes were originally supplied with cast-iron bearings and 'soft' metal spindles. SB did offer a hardened spindle as an option on the 415, but I am relatively certain that mine is the soft version, looking at the damage (see photo's below). This was before they started fitting bronze bushings to the headstock bearings on later models. I found a used replacement for the spindle, which appears to be in good nick, and which I assume is also soft metal

My idea is to fit the 'new' spindle inside a Babbitt casting covering the existing bearings, but I am not sure how to make it work. The clearances between the spindle and bearings are probably too tight to allow pouring white metal without any pockets or irregularities getting formed because of the limited clearances? Also, these headstocks were made as one unit with the bearings bored out and ground and scraped to fit. They do not have top halves that can be removed, only a groove on one side for shims. Because of this I would have to cast the Babbitt with the headstock standing on its side.

I would like to do this myself and not have to go to a pro machine shop at enormous cost and inconvenience.

Is it a silly idea, or/and are there any other suggestions/solutions that could work?

Thanks in advance for any help you can offer
IMG_7123.jpgIMG_7130.jpgIMG_7007.jpgIMG_7180.jpgIMG_7024.jpg
 
We've all seen far worse. If you adjust the clearances, keep them well oiled and don't run at higher speeds you should be able to do surprisingly good work with what you have. That being, said someone posted, years ago, about boring the head stock and making bronze bearings. It probably isn't worth it because the condition of the rest of the lathe is the same as your bearings. Just "run what you brung" and save up for a better machine.
 
A question i have. If you use the old spindle, can you set oil clearance, or is it too wore out ? Though ugly with scoring, if you use clean oil and set thrust so that scoring of spindle and headstock align. . . If you can set oil clearance to . 001" to . 002", then it will run fine.

If i was going to repair i personally would not use babbit. I would bore the headstock journals a larger ID, and make a bronze bearing to go into bore. You could put a single cut on that bronze bearing as well for oil clearance adjustment.
 
Polish the spindle to remove the highs spots only, a new oil stone works good for this with the spindle in a different lathe. remove some shims but not all, and use a sunnen hone to clean up your bore, but DONT hone to much and use the carriage to keep the hone squire with the bore( you will have to make a jig)...hone to give your spindle clearance only...be careful...Phil
 
I'd personally stone to remove any burrs on the spindle and see what the clearance is first. If it's reasonable and you don't have any problems turning I'd leave as is. It might drink oil, but oil is cheap and the odds of screwing things up is pretty high.
 
Boring out the headstock, making bronze or cast iron inserts, turning down the spindle or buying a new spindle. is a job that is so much work, you might as well buy a spindle from a modern ball bearing lathe, bore out the headstock and press bearings in.
 
We've all seen far worse. If you adjust the clearances, keep them well oiled and don't run at higher speeds you should be able to do surprisingly good work with what you have. That being, said someone posted, years ago, about boring the head stock and making bronze bearings. It probably isn't worth it because the condition of the rest of the lathe is the same as your bearings. Just "run what you brung" and save up for a better machine.

Karl, thanks for the quick response. I might just do what you suggested. I had a look at the ways and it seems they also have been violated, so you are right: the rest of the lathe is probably the same as the bearings. I will test the clearance between the spindle and bearings, and if that is OK, say within 5 thou, I will just add oil and hope for the best. Thanks again for the advice.
 
A question i have. If you use the old spindle, can you set oil clearance, or is it too wore out ? Though ugly with scoring, if you use clean oil and set thrust so that scoring of spindle and headstock align. . . If you can set oil clearance to . 001" to . 002", then it will run fine.

If i was going to repair i personally would not use babbit. I would bore the headstock journals a larger ID, and make a bronze bearing to go into bore. You could put a single cut on that bronze bearing as well for oil clearance adjustment.

Thanks texasgunsmith, I was thinking along the same lines after I read Karl's post. I am hoping the clearance is between 1 and 2 thou of course, but I suspect that is probably too much to hope for. If I can't bring the clearance down to acceptable level, I think the bronze bearing option is probably the safest option.
 
Polish the spindle to remove the highs spots only, a new oil stone works good for this with the spindle in a different lathe. remove some shims but not all, and use a sunnen hone to clean up your bore, but DONT hone to much and use the carriage to keep the hone squire with the bore( you will have to make a jig)...hone to give your spindle clearance only...be careful...Phil

Phil, thanks for this. It seems I will have to take this route if I cannot get the clearances needed as texasgunsmith suggested for the headstock spindle. Now at least I have a plan B...:)
 
Phil, thanks for this. It seems I will have to take this route if I cannot get the clearances needed as texasgunsmith suggested for the headstock spindle. Now at least I have a plan B...:)
I think he meant that you stone the high spots off before trying to fit the spindle clearances. The high spots will poke right through your oil layer and rub metal to metal making the scoring worse. Low spots are fine, low radial lines are fine to a point but any high spot needs to be removed.
 
kissing the bore with a ball hone would knock the high spots off [not a lot just kiss it] and then a good scrub with some fine steel wool and a good flush and then some 600 wet and dry of the spindle then a light fine wire wheel to burnish it and i think you will be surprised . but as the ol boy i use to work for would tell some of his customers new will fix it but i think you will find there's plenty of life left in it you just need to massage it a bit
 








 
Back
Top