SIP 12in bandsaw - seized bearing on bottom sawblade wheel

[Croyboy]

I have had this for a few months now (second hand ) and it has started to screech. I have taken off the lower wheel and the insidebearing is seized. I can get it to rotate a little but it is very rough. I have looked at earlier posts and people talk about tapping out the bearing. I am no engineer and, with this lockdown have limited access to engineers. So I am asking for any help and advice from the forum.
I have two new bearings on order ( hopefully arriving tomorrow ) in case l need to replace the existing.
I have read lots of stuff on the internet about using heat, the danger of tapping out, the need for special tools etc - net result is total confusion!
I hope there is someone out there who has "been there, done that " with the same bandsaw who can point me in the right direction.
Thanks in advance.
Patrick

 

[Ttrees]

Hello
Just incase you haven't seen these ones...
Jack Forsberg has made a few videos on bearings which I found very helpful when doing the same job.
[youtube]ocsnUBYEyuM[/youtube]
[youtube]gRX4b12tGtI[/youtube]

Tom

 

[Croyboy]

Thanks Tom

 

[CHJ]

Even if you have double rubber sealed replacement bearings consider putting a close fitting cardboard washer on the outboard side to add an additional blockage to any dust doing its best to accumulate and packing against the bearing.

Since doing this when I found a dust seized bearing despite strong extraction, I've gone quite a few years without any bearings ingesting dust.

 

[Croyboy]

Thanks for reply Chas.
The bearing is totally seized and is a sealed unit - cannot remove the shield. I am just not sure/confident how to get the bearing out.

 

[CHJ]

Thanks for reply Chas.
The bearing is totally seized and is a sealed unit - cannot remove the shield. I am just not sure/confident how to get the bearing out.

You will probably find the bearing is packed with dust and is scrap so:-
Place the wheel, seized bearing side down with centre boss supported and tap the bearing out from the other side through the other bearing centre bore with a suitable piece of metal rod or hardwood dowel, work round the bearing to reduce any tendency for it to tilt.

 

[boschboy]

use a socket and tap the bearing out simple

 

[Croyboy]

Tapped out the seized bearing through the bore of the other bearing as advised- fitted new bearing and cardboard shield and the saw is running great!
Thanks for all the advice guys.

 

[Eric The Viking]

Sorry I came too late to this , but just in case someone else comes across this with the same problem, I have struggled with mine in the past, but now have a really easy answer:

The issue with the SIP wheels on mine are the way the bearings are located: normally you'd expect a pair of shoulders in the middle of the wheel, against which the bearings are located. Instead there are two grooves, taking circlips.* I couldn't get a drift past in order to tap out the failed bearings (bottom wheel - top wheel was dead easy).

I found that a 12mm expanding "Rawlbolt" makes a perfect extractor. They are intended for machine anchors in concrete, etc - the thread is 12mm, and as you tighten down, the metal plug part expands to grip the sides of the hole. But it doesn't do this evenly - as supplied the bottom of the anchor expands more than the top. By reversing the plug on the long bolt, you can make an expanding extractor - it goes easily through the first bearing, then will expand to grip the second one underneath, so you can tap it out.

Mine came out so easily they could have been re-used (of course they were badly worn, but not damaged by the extraction).

Pics to follow when I get to the 'shop later today.


*This seems doubly daft, as it probably meant two different boring operations to make the wheels, and is less practical than the normal approach.

 

[CHJ]

Tapped out the seized bearing through the bore of the other bearing as advised- fitted new bearing and cardboard shield and the saw is running great!
Thanks for all the advice guys.

Glad you sorted it, that fine dust is attracted to the rear recess of the wheel bearing boss and thence passed the bearing shields is perverse, it's reasonably understandable that some will be deposited by centrifugal force on the periphery of the spokes but why it is drawn into an inner 'hole' is strange.