Bandsaw restoration advice.

[PeterBassett]

Hi all.

I bought a Multico 16" bandsaw last week and it is in need of a little TLC. I've started striping it down to clean and check it over and I need some advice on the top wheel bearings.

Firstly, this is the machine (as of this evening)

All the guards are off, the table is off and already mostly clean. It was covered in globby paint.

I need some advice on the top wheel bearing which is louder than the bottom and doesn't spin for as long. I have a video of a comparison between the two here.

http://www.flickr.com/photos/petebassett/4707551200/

You can hear the top bearing quite well and the bottom one is barely audible.

I decided to take the wheel off to change the bearings but that has proven to be more difficult than I had expected. I have removed the outside bearing cover. Here you can see the outer bearing (I assume there are two). It is marked SKF, which I believe are pretty good.

and the inside cover

but the wheel will not some off the shaft using reasonable hand strength. I thought better of trying anything else until I'd had a second opinion, so I put it back together.

So, how hard should it be to get the wheel hub off the shaft? Is it a bearing puller job?

The hub had a grease nipple and the inside is packed with grease, will the new bearing need to be of the same type?

Anyones thoughts on this would be greatfully accepted!

Cheers all.

Pete

 

[Noel]

Peter, nice piece of hardware.
Don't know if it will help but there should be an ID on the bearing, especially if it's an SKF. Might need an eye loupe or magnifying glass to see the markings. Once you have them just call a bearing supply company with the info and you'll get an identical replacement (SKF or similar).

Regarding the wheel and shaft, can't really help you, maybe try a couple of wooden wedges top and bottom with 2 hammers striking the wedges at the same time.

 

[PeterBassett]

Thanks very much.

Now you mention it there are other markings on the bearing. I'll have a look tonight. Cheers.

Anyone else?

Bumped for the day shift...

 

[OldWood]

Pete
The bearing has to be a tight fit on both the shaft and the wheel body, otherwise it won't really be a bearing ! That is if it was just a gentle push fit, it would move on the shaft / housing with the forces involved.

You're going to either make a giant size bearing puller, or some way of driving it off the shaft from the back.

Over to you I'm afraid.
Rob

 

[OldWood]

Having had another look at it, it looks to me as if the wheel is held onto a separate bearing housing with the three recessed bolts, which might well be a logical method of manufacture. Again this will be a reasonably tight fit so a bit of persuasion will be needed with a hammer and a block of wood.

Once you have the wheel off, then a standard bearing puller is the solution (go and visit a friendly local garage and they will do it for you), followed by knocking the bearing out from the rear of the housing. Reassembly is just the reverse of this of course.

Rob

 

[Racers]

Hi,

They might be three threaded holes for a puller to be attached to.

Pete

 

[PeterBassett]

Hi, those three bolts do indeed keep the wheel on the hub. I've already had the wheel off. Thats why there is a blue line to show where it should be aligned when I put it back on.

I understand what you say about needing it to be a tight fit.

Will pushing the hub back onto the shaft with new bearings damage the bearings at all? I would have thought pushing the actual bearings, where they contact each part (hub or shaft) would result in no damage. However, I havent been able to figure a way to push the hub back on, only pushing the bearings, when there are two bearings in the hub, which I assume there are.

 

[Racers]

Hi,

I was talking about the three holes in the hub round the bearings.

There should be a spacer between the bearings so you can tap the whole assembly back on to the shaft, using a tube or socket that fits the inner race of the bearing. That won't damage the bearing likewise when you fit the bearings to he hub only tap the outer race of the bearing.

Pete

 

[PeterBassett]

Ah, I see. Those holes are for the hub bearing cover. They may well be intended to do double duty though.

Using a tube or socket that fits the inner race of the bearing. That won't damage the bearing likewise when you fit the bearings to he hub only tap the outer race of the bearing.

That is the bit I am having trouble visualising. If you fit the two bearings and spacer as one assembly to the shaft and then fit that into the hub I cant see how you'd be able to knock it in without hitting the top bearing when the bottom one is the one being pressed in. The spacer can't touch both the inner and outer race surely.

I can visualise fitting one bearing at a time to both the shaft and hub at the same time. Like this.

Sorry if this is all a bit simple for you, it's new to me and I want to get it right.

 

[Racers]

Hi,

You need to remove the hub and fit both bearings, then fit the hub to the shaft. So once you have it apart tap in the bearings round the outer edge to seat them into the hub, there will be a shoulder for them to fit up aganst (grease both the hub and bearing) then with a tube or socket that only touches the inner race tap the hub onto the shaft (more grease).


Pete

 

[PeterBassett]

That makes a lot more sense than my way, thanks Pete. The spacer between the bearings transfers the force from the top bearing to the lower, stopping any damage.

Thanks again.

Pete

 

[JMcK]

To replace the bearing it might be worth, as mentioned above,visiting a friendly local garage. They will have a bearing press which will be more accurate and less likely to cause damage than just trying to knock them in.IMO.

 

[PeterBassett]

I assume you recommend letting them get the old ones out too?

If you look at the shaft here where it meets it's mount on the right, you'll see that the shaft has a pin through it. I'd have to knock this through to remove it. Or just take off the entire tension mount with the four bolts as shown in the first photo.

Thoughts?

 

[Racers]

Hi,

I have seen a local garage pound a wheel bearing on with a length of scaffold pipe and a 'kin big hammer!

Thank god it wasn't my car.


Pete

 

[PeterBassett]

I have a sledge hammer and some hefty rocks.

Are these the tools du jour?

:lol:

 

[Racers]

sledge hammer and rocks, thats just showing off :wink:


Pete

 

[JMcK]

Hi,

I have seen a local garage pound a wheel bearing on with a length of scaffold pipe and a 'kin big hammer!

Thank god it wasn't my car.


Pete

You must frequent the wrong kind of garage. :lol: :lol:

PeteB, You can always ask them if they have (and will use ) a bearing press before entrusting it to them.

Don't throw any of those rocks this way. :lol:

 

[PeterBassett]

I'll get back on this tonight and see how it goes.

I've got to get it all off first, or find a bearing puller.

Thanks for all the advice from everyone. It's much appreciated.

Pete

 

[dickm]

In the days when I drove old Volvo 120s, the local garage used to borrow MY puller to get the hubs off .

But seriously....
Not sure about refitting both bearings into the hub and then pressing them on to the shaft UNLESS there is also a sleeve between the two, not just the shoulders mentioned. Without the sleeve, the inner bearing would be stressed because there was nothing pushing the inner ring of the race as the outer ring was being pressed in by the shoulder.

 

[PeterBassett]

Hi again.

Adventures With Bearings!

I got hold of a three bearing pullers and another thing that I thought might be to insert bearings, any thoughts?
The Large puller is too large, the Medium one doesn't work as the thread is gone but the Little one is just right.

So, I started to dismantle the hub ready for the puller. And got carried away and didn't take any photos. It came off nice and easy. I used a nut to go in between the puller and the shaft to save on damage.

And here is the hub off the machine, still with one bearing in it. You can also see the spacer that was indeed between the two bearings on the shaft.

Now a setup shot of how I got the second bearing off the shaft.
I'm sure this isn't how you do it when you care about the bearings.
I was wearing eye protection incase the bearing exploded or something! In the end it came off just as easily as the hub.

This is how I pushed the remaining bearing out of the hub. There are three washers and a nut filling the space in the internal diameter.

The washers are officially knackered, but it did work.

So, now I have two SKF 6204 JH bearings to replace.

ID : 20mm
OD : 46.9 or 1.849 inches
Thickness : 13.95mm

I've found these
http://uk.rs-online.com/web/search/searchBrowseAction.html?method=getProduct&R=2867990

Which are near as dammit the right size. I'd bet its my Aldi calipers that are off.

The ones I have from the hub are open. Would I be better off just getting the same type, as in the link, or rubber sealed ones?

Cheers.

Pete