Delta 46-250 bearing noise

[Bats]

I've been running into some crunchy noises coming lately from the headstock of my little Delta 46-250 midi lathe lately - especially at higher speeds, and worsening over time - and I'm having trouble drawing any conclusion other than "I needs me some new bearings". I've got what I think (read: hope) are the right parts, but has anyone done a replacement on one of these units who can give me a brief rundown on the procedure?

I've removed the pair of setscrews holding on the handwheel, and the one setscrew from the pulley, but the spindle doesn't seem like it's inclined to come out, and I'm a little hesitant to just start pounding on the end of it with a dead-blow hammer.

 

[jrista]

While I haven't disassembled this particular lathe, I've disassembled plenty of machines with bearings and shafts of one kind or another.

The spindle should be passing through a series of bearings, and of course the pulley. It also passes through some locking rings, according to this (part 29):

Delta 46-250 - Midi-Lathe Type 1 - eReplacementParts.com

Fix your 46-250 Midi-Lathe Type 1 today! We offer OEM parts, detailed model diagrams, symptom-based repair help, and video tutorials to make repairs easy.

www.ereplacementparts.com

I suspect its part 29 that is currently restricting your ability to remove the spindle. I am not sure exactly where that sits, and whether you can see it and get at it, or not. I suspect that is your first hurdle, though. If you can get those locking rings out, then you should be able to slip the spindle and the bearings out of the headstock and pulley.

The tricky part after that is keeping it all aligned as you remove the spindle. If you end up pulling at an angle, it can seize up inside one or more of the other parts.

 

[maxwell_smart007]

Before you take it apart, did you look at the pulleys and the belt? Worn parts can sometimes make a bunch of noise - especially Reeves drives.

Does the lathe run true, or is there any play to the spindle shaft?

Looking at the part diagram, there's a key in the spindle shaft too...

 

[maxwell_smart007]

 

[Bats]

The spindle should be passing through a series of bearings, and of course the pulley. It also passes through some locking rings, according to this (part 29):

I suspect its part 29 that is currently restricting your ability to remove the spindle. I am not sure exactly where that sits, and whether you can see it and get at it, or not. I suspect that is your first hurdle, though. If you can get those locking rings out, then you should be able to slip the spindle and the bearings out of the headstock and pulley.

Looks like some sort of circlip from the diagram, although the resolution makes it tough to tell just how everything goes together. It isn't visible/accessible on the machine, though, which makes me suspect it's meant to come off later in the process.

Also, I found a copy of the user's manual online (mine was used and sans-manual):
https://web.archive.org/web/2019021...s.com/download/Delta-Lathe-Manuals/46-250.pdf

It doesn't cover bearings, but it does (on page 11-12) deal with replacing the belt, which also involves taking out the bearing shaft, and makes it look like I wasn't too far off with the idea of a dead-blow hammer.

Before you take it apart, did you look at the pulleys and the belt? Worn parts can sometimes make a bunch of noise - especially Reeves drives.

The belt looks ok - at least from what I can see (checking the surface will involve removing the belt, which goes back to pulling the bearing shaft) - as does the pulley. And this is a pretty bare-bones lathe - nothing as fancy as a Reeves drive in there. I also checked out any source of vibration I could isolate - originally thinking it might just be a loose part or cover rattling - but without any luck.

Does the lathe run true, or is there any play to the spindle shaft?

Seems to run true, and no play that I could detect.

Looking at the part diagram, there's a key in the spindle shaft too...

Yep. I'm pretty sure that's there to keep the pulley from spinning on the shaft.

The video looks pretty straightforward (and the sound at the beginning sounds pretty familiar), and the lathe looks close enough (which should teach me to look for "lathe bearing" not "Delta 46-250 bearing" next time I'm searching), so I'm going to give it a try. If you don't hear back from me, send help!

(well, more help. you've both helped already)

 

[jttheclockman]

Suggestion and have learned this one the hard way. Take photos and take notes for future repairs. Good luck. Maybe a bearing problem movement. The bearing on my alternator just went bad and basically fell apart. Belt came off and had to limp home. Forgot what it was like steering with no power steering. Not fun.

 

[Bats]

Good news - I managed to get things apart, and (with only somewhat more difficulty) back together again. Better still, the noise seems to be gone, and the machine actually feels like it's running smoother - something I'm not sure I even realized was lacking.

Everything did indeed come apart with some gentle deadblowing - it turns out the circlips don't really prevent anything from coming apart - and, indeed, can't be removed until after the whole spindle/pulley/bearing assembly comes out. They're just there to give the bearings a mating surface to mount against while simplifying the headstock casting.

Putting it back together took a couple false starts - first to get the new inboard bearing on the shaft (there's a collar on the shaft of the Delta that prevents flipping the shaft around and using the casting like in the video - I used the jaws of a bench vise to play a similar role), and then because there's a spring washer underneath the outboard bearing that I forgot to replace the first time around.

All in all, far more straightforward than I'd feared (the last bearing replacement I did was on a knee mill, and took a few months). Which is good, because I forgot to take pictures and didn't see John's helpful reminder until after I was done. Sorry to hear about your alternator.


One other note, for whoever (read: probably me) finds this thread in the future when they're looking for replacement bearings: The inboard bearing is a 6005RZ and the outboard is a 6004RZ. Now you (read: I) can substitute better (or worse/cheaper) quality bearings rather than relying on the official Delta/Dewalt parts suppliers.


Thanks for the help, everyone.

 

[Don Hess]

Good news - I managed to get things apart, and (with only somewhat more difficulty) back together again. Better still, the noise seems to be gone, and the machine actually feels like it's running smoother - something I'm not sure I even realized was lacking.

Everything did indeed come apart with some gentle deadblowing - it turns out the circlips don't really prevent anything from coming apart - and, indeed, can't be removed until after the whole spindle/pulley/bearing assembly comes out. They're just there to give the bearings a mating surface to mount against while simplifying the headstock casting.

Putting it back together took a couple false starts - first to get the new inboard bearing on the shaft (there's a collar on the shaft of the Delta that prevents flipping the shaft around and using the casting like in the video - I used the jaws of a bench vise to play a similar role), and then because there's a spring washer underneath the outboard bearing that I forgot to replace the first time around.

All in all, far more straightforward than I'd feared (the last bearing replacement I did was on a knee mill, and took a few months). Which is good, because I forgot to take pictures and didn't see John's helpful reminder until after I was done. Sorry to hear about your alternator.


One other note, for whoever (read: probably me) finds this thread in the future when they're looking for replacement bearings: The inboard bearing is a 6005RZ and the outboard is a 6004RZ. Now you (read: I) can substitute better (or worse/cheaper) quality bearings rather than relying on the official Delta/Dewalt parts suppliers.


Thanks for the help, everyone.

Thanks for the bearing numbers! I just swapped out the noisy bearings on my Delta midi 46-460 and saved a lot of money!!