Spindle bearing woes

Cadillac said:

So I understand this correctly. The bearings do mate together parrallel and flush with each other? It's the caps of the bearings that have a taper to the horizontal surfaces that mate to the headstock. Hope I described that clearly? Then work can begin on bearing fitment to spindle by means of scraping.

Click to expand...

Hi Cadillac, Thats about the size of it. You're never going to get the bearing shell truly round, and really very carefully scraping in is about the only real way of getting a good shaft to shell fit. Without the ability to close up the shells, you won't be able to discover where to scrape.

If the shells meet without grabbing the spindle shaft, then the only place you can remove any material, is from the mating edges of the top shell.

Izzy said:

Sorry guys been busy lately but I think I better understand what's going on. So my next step would be to mill the slope off the bearing caps then blue up the spindle and scrape to size?
I thought about Babbitting the bearings but I think ultimately after this I'll probably make new ones the way things have been going for me I'll probably be working for the ole mold shop again then I'll have all sorts of machines at my disposal they allow you to use any machine you want when you're off hours so long as it's not being used for a job.

Click to expand...

Hi Izzy,

Yes you have got it ! But don't forget the shims !
If you really wanted you could actually fit roller bearings, it might be easier than trying to reproduce those bronze shells.
Nice about getting back into the mold shop, its good that you have the use of the machinery there. I do miss being able to use some old friends, now departed, workshops ! Working alone can be a bit soul destroying.

@BaronJ I know exactly what you mean I work alone alot! And usually when I want to learn something i try to teach myself as best I can by watching videos and reading articles and such. Part of the reason I'm here asking for help is cuz I dont really have anyone else to turn to for advice this was sorta my last chance at trying to learn something new so I could fix the thing. I wouldn't mind going the roller bearing route although I don't think I'd have a problem producing those shells so long as I have a machine to do it on. Some of the jobs we used to get had half thou tolerances and i could make it happen.
So as far as scraping goes I've never done that, I've heard I could grind and hardned an old file to do the job? I'm gonna need a crash course on scraping before I get there. I understand the blueing and marking process, its the actual motions and mechanics of it that I'm unsure of. And how to shape my scraper?

Hi Izzy,

Thank you for your nice words. As you have probably gathered by now, I'm getting a bit long in the tooth, so hands on is becoming hard work.

If I can find my scrapers, I'll take a picture and post it. They are quite straight forward to make, but you are going to need a curved one with a fairly long narrow end. My scrapers are Starret ones, passed down from my Grandfather. He was a mining engineer.

When you get around to bluing up take some pictures. You probably won't need to take very much material off and it will primarily be in the center part of the shell.

Don't even think about taking any material out of the bottom half's at all. Doing so will alter the lathe spindle center hight, which you definitely don't want.

Absolutely not touching the bottom bearings, just the tops! My sister is getting married in the next couple weeks so things have been hectic for me but, I'll report back when I'm at the blueing process.
Just out of curiosity how would I go abouts converting it to roller bearings?

Hi Izzy,

Seriously ! I wouldn't. You would have a major machining job on both the spindle and the housings. Plus you could easily be talking several hundred dollars for a single bearing, never mind two of them. You would still need a pair for the tail end of the spindle.

It was a little naughty of me to throw that into the mix. My apologies.

Congratulations on your sister getting married. Best thing that ever happened to me. Coming up nearly 50 years. How time flies.

As far as your lathe is concerned, think about what you are doing, what you need to do and how you are going to do it, and it will work out just fine.

@BaronJ I just did some reading on converting a plain bearing lathe to roller bearings and I'd have to agree! I think when the time comes I'll stick to just making new bronze bearings I'd like to keep this lathe tho it's a real piece of Canadian history I've only ever talked to one other person who has one of these and he's in Quebec!

Hi Izzy,

Pictures of one of my curved scrapers, as promised !

As you can see the blade is 5.5" inches long plus the handle. Its only the end 1.5" inches or so that is used.
I believe these scrapers to be over a 100 years or so old. I think there were six in the set, but I was only able to locate four of them this morning.
I think it is the large and small triangular section ones that have gone missing. There is one large and one small curved one, this one and a large and a small square ended ones. I also have a Sandvic one which takes carbide tips.