How to get stubborn bearings off bandsaw guide posts?

[CMax]

Hi all,

So I took delivery of my new-to-me SCM S45 bandsaw recently and I need to replace some of the bearings. The lower ones are basically seized, or at the very least, too gritty to spin freely. I've got some new, replacement bearings on the way. However, I just tried to remove the bearing from the guide shaft and... no bueno. It's stuck. I managed to get it to move about 5mm with a lump hammer, but the shaft is now level with the bearing so this approach is no use.

What's the best way of getting these off (and new ones on, if the fit is supposed to be this tight)? I've tried to call SCM but they're not interested as I'm not a company with an account with them and they want me to fill our paper forms before anyone will even talk with me! I've looked online and mostly found kids messing with skateboards or blokes with transmissions and whatnot.

I'd rather not use blow torches, welders, high-powered hydraulics etc. Mostly because I don't have any of that. I don't even have a vice currently (I'm in the middle of a move and haven't had one for years before I returned to woodworking).

Would a bearing puller be the thing to use here, or is there another method? I've found this one on Amazon, would that do the trick?

Here's the bearing and shaft (I'll be doing 4 of these):

Any help will be greatly appreciated, especially as I'm not particularly mechanically minded.

 

[Lorenzl]

One way without specialised tools:
Soak the bearing shaft with WD40 or similar
Open the bench vice jaws slightly wider than the shaft
Place the bearing on the top of the jaws with the shaft down
Hit the shaft in the centre of the bearing with a brass rod as large a diameter as possible smaller than the bearing ID
Use safety glasses

Leaving overnight in the freezer may help a bit?

 

[Lorenzl]

The bearing puller would be a good way but it would work better with a dimple in the shaft to help locate the centre.

Soak the bearing shaft with WD40 or similar
Fit the bearing puller and put some tension on using the thread; if it starts moving good. If not then hit the top of the hexagon with a hammer; the shock sometimes releases any stick.

With either method the bearing may break apart as you are relying on the balls to stay in place.

 

[Spectric]

Worst case grind a notch in the outer race and then give it a sharp tap which will shatter it, remove balls and cage and then grind a flat on the inner race and it will split.

 

[CMax]

Thanks for the advice, Lorenzi. As I don't have a vice at the moment, I was facing having to buy one or the puller. It's good to know either approach is likely to work. They've been soaking in WD40 for a while now, and it'll be at least another day before I have the vice/puller. Hopefully, that'll help things along.

What about installing the new ones? Is there a handy technique for that? Will the new ones just slip on considering the lack of gunk/rust that I'm experiencing with the old ones, or is there a technique/tool for getting them to seat fully?

Thanks for that @Spectric. I'll keep that as a backup option

 

[Spectric]

I managed to get it to move about 5mm with a lump hammer, but the shaft is now level with the bearing so this approach is no use.

Use a brass drift to knock it right out,

 

[Ttrees]

Have you made a start at removing the bearing or was this gap present already.
Just incase there maybe a burr on the shaft end stopping it from coming off.

If the gap was already there, then some thin plate which would fit between
and you can knock it out whilst the plates are supporting the inner race
as to not skew the bearing and marr the shaft.

I'd use a little nut with no burr and sheet of paper or something like that, if I had nothing else.
For this kinda thing I use the "hardy hole" in my "anvil"
(sledgehammer head) or just a hole in a hardwood scrap block if stuck.

 

[CMax]

Use a brass drift to knock it right out,

I don't have one of those, but I'll add it to my shopping list options

Have you made a start at removing the bearing or was this gap present already.
Just incase there maybe a burr on the shaft end stopping it from coming off.

Yes, I already made a start. I managed to knock the proud shaft level with the bearing with a minor tap with my lump hammer. I don't have a vice currently, and no pin/drift/etc so I couldn't get much farther than that. However...

(sledgehammer head) or just a hole in a hardwood scrap block if stuck.

I've since found a sturdy nail punch, so I'm going to give that a quick test in a piece of wood as you suggest. It might not be strong enough, but we'll see...

 

[rogxwhit]

In this circumstance, when you come to tap on the new bearing, use a hollow drift (a suitably sized piece of tube with a flat end) so that installation pressure is on the inner race that grips the spigot, not on the outer race - thus you are addressing the frictional resistance directly and not stressing the bearing structure, which you would be if you were pressing on the outer race.

Pulling the old one off, you needn't worry about such niceties since it's going to be discarded.

 

[MARK.B.]

A good soak overnight in the poison of your choice, a hole in a piece of scrap wood just large enough for the shaft to fit through and using the flat end of a suitably sized bolt rather than a punch which will leave a mark on the shaft end , give it a sharp whack or two and it should pop free. Use a suitable sized socket to gently tap the new bearing into place.

 

[Lorenzl]

Ignore

 

[Inspector]

When reinstalling the new bearings after cleaning up the rods so there is no corrosion or burrs. Put the bearings and rods in their own plastic baggies. The rods go into the deep freeze for a few hours to overnight (better). The bearings into boiling water or an oven on warm (without the bags). The cold shrinks the rods and the heat expands the bearings, the bags keep them dry and frost free. As fast as you can rip them out of the bags and push them together, wear gloves. They should slide together all the way and as their temperature equalizes lock in place. If they don't seat you will need to use the socket/tube/pipe and a press/bar clamp the rest of the way. If you have access to dry ice or liquid nitrogen it is even easier to slide them together but more dangerous, frostbite, if you have never done it before.

The beating you have been doing to remove the bearings may render them to the garbage, Damage to the balls and races.

Pete

 

[TRITON]

I've have many issues like this removing solid axles off bearings from early Hope hubs.
Pretty much as Lorenzi says. Open vice jaws etc.

I also drilled a hole through a piece of wood the diameter of the shaft. This supports the bearing all round so theres less tendency for it to break apart.
Steel hammer and something of slightly smaller diameter and just hit till its out.
I used an old axle and sanded down the diameter so it doesn't just replace one stuck shaft with another.

If you do use a softer metal like brass, it is a good idea to hit it a bit lighter, so the end of the driver doesnt just start to splay. Just plenty of lube like GT85 or 3in1 oil and strike it in sharp taps.

 

[Ozi]

Personally if I didn't have the kit rather than struggle and possibly damage the shafts or new bearings I'd drop around to a local garage of the one man band variety and ask nicely how much to push the old off and the new on. Turn up when they are not busy and you might get a bargain

 

[deema]

This is how we did it. The biggest issue I suspect you will face is getting the hubs back into the wheels. You really need a press.

https://www.ukworkshop.co.uk/threads/scm-minimax-s45-bandsaw-teardown-overhaul.135069/

 

[CMax]

Thanks for all the solutions, everyone. I thought a similar approach would work but as a newb to these kinds of things, I was nervous about ballsing it up. Using the methods outlined here, I've managed to get one off:

I drilled a hole in my flimsy OSB tabletop and supporting 2x4, then used a bicycle crank tool thingy to use as a collar while I gave it a tentative few whacks with a soft-headed hammer and a punch covered with a bit of leather. Worked like a charm for the first one. The second one, however, isn't budging a millimeter. (And no worries @Inspector, I'm being careful with the guide shafts.)

The other two don't need doing. I took them out of the guides, gave them a quick clean up and they spin perfectly fine. I'm going to order a vice and a bearing puller. I'll likely need the former for help replacing the bearings and for other projects so might as well bite the bullet now and pick one up.

This is how we did it. The biggest issue I suspect you will face is getting the hubs back into the wheels. You really need a press.

Hey Deema -- I recently read through that entire post before buying my machine. Very informative. Thanks for sharing all that. Thankfully, these are just the guide bearings and not the wheel bearings. As far as I can tell, there's nowt wrong with the latter. The machine's only had fairly light use and is just three years old. With any luck, I won't have to worry about those for a while.

 

[John Brown]

This is how I did it. I found an scrap piece of 4 by 4 timber and drilled a deep hole of a size to take the shaft in the end. Then I took a club hammer and a bolt of the right size and knocked the shaft out into said hole. Couldn't have been easier. I fitted the new bearings using a vice and some scrap pieces of wood to avoid damaging anything. Also couldn't have been easier.

 

[MARK.B.]

Just give the stubborn one another overnight soak and try again, My advice and I could well be talking out me bum, but If it twer me i would change all four and that way you know you are starting on a level playing field. If the first two were stuck then there is a good possibility that the two you don't change will only become even more of a pain when the time comes to change them.

 

[deema]

My Bad

The easiest way with the simplest tools is just put the shaft in a vice with the bearing sitting in the checks and the shaft loose and just tap the shaft out. Warm the bearings to around 80C (in a cardboard box in the oven works well and keeps any oil off everything) and / or the shafts in the freezer over night and they should just slip on. Do not overheat the bearings, if you do you will need new ones.

 

[CMax]

Just give the stubborn one another overnight soak and try again, My advice and I could well be talking out me bum, but If it twer me i would change all four and that way you know you are starting on a level playing field. If the first two were stuck then there is a good possibility that the two you don't change will only become even more of a pain when the time comes to change them.

You're probably right with doing all of them... but laziness...

And yep. I've got the stubborn one soaking as we speak. I'll have the vice from Amazon tomorrow so that should make it a bit easier than my current hold-in-the-tabletop.