Eric The Viking
Established Member
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- 19 Jan 2010
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Posting this in case it's helpful to someone:
I have an old SIP 12" bandsaw. I have had it pretty well fettled in the past, but it's had a couple of years of almost no use, and last winter didn't help it, being out in the damp gar, er, workshop. Now I need to use it, and I need it running as sweetly as possible.
A quick check revealed:
- perished tyres on both wheels
- bearings shot on the upper wheel (bottom wheel just about OK)
- one bearing shot on the jockey wheel/tensioner for the drive belt
- drive belt way too inflexible (basically shot)
- upper guides all shot (rotating bearing type)
Pretty much all the above has an effect on cut quality, mostly because of causing the blade to wander about and causing unhelpful noise and vibration. The belt issue puts unnecessary load on the motor, too.
I long ago gave up on the importer, because of cost and quality and simply, "no we don't keep those -- it's far too old!" But the bearings in particular are very standard parts, and it has been possible to source them here - not only that but to replace the nasty Chinese originals with decent SKF ones from Italy, that are properly dust sealed.
Suppliers
Simply Bearings had everything I needed, were the cheapest I could find (who had everything), and delivered "free" by Royal Mail overnight.
Drive belt Solutions seem to keep a lot of belts for a lot of machines. They had two different grades of quality for my machine - I've gone for the more expensive one, in the hope it's more robust and not damaged by sawdust.
You can just look up your machine by make then model on their site. This was way better than trying to chase down the right code. There's a bewildering range, and it seems that it's actually a small automotive size, rather than an industrial one. Certainly I could only find the length used amongst the automotive sections. I wasted far too much time looking!
Finally the tyres. It turns out that, years ago, Axminster's bandsaw manufacturer made very, very similar wheels to the ones on my machine - the tyres fit. They still keep spares for their machines, and at a very sensible price. I don't think you can order spares online, so I called (I had their part no.), and it took a minute or so. NOTE: I think it's a bit unreasonable to expect them to know what fits third party machines, so I did that bit of research myself. To an extent I'm taking advantage, but they get a lot of business from me anyway, and it's only once every four years or so
. . .
I'm waiting on the drive belt unfortunately, as everything else arrived yesterday and has been fitted.
Process
The main wheel bearings are a friction fit in the hubs. you can't easily tap them out and they're too small for any puller I have. They're also kept in the right place by two internal circlips in the middle of the wheel. These get in the way when you try to tap out the outer race from the other side. But... starting with the wheel really cold and heating the hubs quickly with a blowlamp meant the aluminium expanded enough to get the bearing to drop out really easily (repeat for the other side of the wheel). They're too small for a puller, so this was a relief. I don't have a fly press either, so installing the new ones meant cooling the bearings, and heating the now-empty hubs again. It works better that way round! I ought to do the driven (bottom) wheel too really, but the previous owner had already fitted SKF bearings and there's no obvious play or noise, so I decided to leave well alone. It has a lot more mass than the top wheel, too, so is a lot harder to heat up appropriately.
Final tip: on my machine, the top wheel looks almost the same both sides, but isn't - it's asymmetric. I've marked it so I don't fit it on backwards -- you feel a right twit when the blade won't track properly and the guides are all off...
So I haven't applied power yet, but everything turned by hand is much smoother than it was.
Hope the above is useful to someone.
E.
I have an old SIP 12" bandsaw. I have had it pretty well fettled in the past, but it's had a couple of years of almost no use, and last winter didn't help it, being out in the damp gar, er, workshop. Now I need to use it, and I need it running as sweetly as possible.
A quick check revealed:
- perished tyres on both wheels
- bearings shot on the upper wheel (bottom wheel just about OK)
- one bearing shot on the jockey wheel/tensioner for the drive belt
- drive belt way too inflexible (basically shot)
- upper guides all shot (rotating bearing type)
Pretty much all the above has an effect on cut quality, mostly because of causing the blade to wander about and causing unhelpful noise and vibration. The belt issue puts unnecessary load on the motor, too.
I long ago gave up on the importer, because of cost and quality and simply, "no we don't keep those -- it's far too old!" But the bearings in particular are very standard parts, and it has been possible to source them here - not only that but to replace the nasty Chinese originals with decent SKF ones from Italy, that are properly dust sealed.
Suppliers
Simply Bearings had everything I needed, were the cheapest I could find (who had everything), and delivered "free" by Royal Mail overnight.
Drive belt Solutions seem to keep a lot of belts for a lot of machines. They had two different grades of quality for my machine - I've gone for the more expensive one, in the hope it's more robust and not damaged by sawdust.
You can just look up your machine by make then model on their site. This was way better than trying to chase down the right code. There's a bewildering range, and it seems that it's actually a small automotive size, rather than an industrial one. Certainly I could only find the length used amongst the automotive sections. I wasted far too much time looking!
Finally the tyres. It turns out that, years ago, Axminster's bandsaw manufacturer made very, very similar wheels to the ones on my machine - the tyres fit. They still keep spares for their machines, and at a very sensible price. I don't think you can order spares online, so I called (I had their part no.), and it took a minute or so. NOTE: I think it's a bit unreasonable to expect them to know what fits third party machines, so I did that bit of research myself. To an extent I'm taking advantage, but they get a lot of business from me anyway, and it's only once every four years or so
. . .
I'm waiting on the drive belt unfortunately, as everything else arrived yesterday and has been fitted.
Process
The main wheel bearings are a friction fit in the hubs. you can't easily tap them out and they're too small for any puller I have. They're also kept in the right place by two internal circlips in the middle of the wheel. These get in the way when you try to tap out the outer race from the other side. But... starting with the wheel really cold and heating the hubs quickly with a blowlamp meant the aluminium expanded enough to get the bearing to drop out really easily (repeat for the other side of the wheel). They're too small for a puller, so this was a relief. I don't have a fly press either, so installing the new ones meant cooling the bearings, and heating the now-empty hubs again. It works better that way round! I ought to do the driven (bottom) wheel too really, but the previous owner had already fitted SKF bearings and there's no obvious play or noise, so I decided to leave well alone. It has a lot more mass than the top wheel, too, so is a lot harder to heat up appropriately.
Final tip: on my machine, the top wheel looks almost the same both sides, but isn't - it's asymmetric. I've marked it so I don't fit it on backwards -- you feel a right twit when the blade won't track properly and the guides are all off...
So I haven't applied power yet, but everything turned by hand is much smoother than it was.
Hope the above is useful to someone.
E.
