Bandsaw blade resonating

[OldWood]

The wood working club that I'm a member of has a Basato 5 (Sheppach) bandsaw. Due to an error on my part of buying Steve Maskery's DVD - - and admitting to it - - I have landed currently with maintaining this machine.

This was OK when it was just tweaking the guides, etc, but became far more serous when the brake on the motor burnt out and I had to sort all that out, and in due course fit a new motor with brake.

Anyway that was just to get your sympathy. Unrelated to the motor problem is that it is fitted with a 25mm blade and, if the belt is on the high speed pulleys, this blade goes into resonance and oscillates all over the place. Tensioning it up doesn't help. The cure is to run it at the lower speed - do we have a fault, a bad blade or is this to be expected with a bigger blade?

Rob

 

[iajon69]

It could be a bad blade, but I can pretty much guarantee that it's down to the width of the blade and the machine not being able to tension it enough.
Even though the machine is supposed to take a 1" blade and it will seem as if it's tensiong it ok, from what's happening then I would say that it's not tensioning the blade sufficiently.
It's not always best to go for a wide blade - a properly tensioned narrower blade will always be better than a wider blade that might not tension correctly.

I would be very surprised if the problem didn't disappear with a narrower blade.

Ian

 

[ondablade]

I've recently sold a similar machine - basically because of a similar issue to do with blade vibration on deep 5in + deep rip cuts with all of the varieties of good quality 3/4 in blade I tried. (Tuff, Sheppach, Starrett etc in various forms)

The vibration was most apparent as a harsh sound coming into the saw when cutting, but it led to blade drift where on lighter cuts there was no issue. The vibration wasn't really visible, but could easily be felt by holding a light stick against the side of the blade.

It's hard to be 100% sure (and there may be set ups that avoid it), but so far as I could tell the issue seemed like it was simply that it couldn't apply enough tension to the blade to move it into a zone where it didn't resonate...

 

[Steve Maskery]

Hi O
I hope that your error was only to admit in public...!
I'd say that I agree with the diagnosis. Just because the wheels are 25mm wide it doesn't mean that the machine can tension such a wide blade. Indeed, I make that very point in Workshop Essentials 4. Remember the scene with the rubber bands?

So the answer is to user a narrower, thinner blade that the machine can tension properly. One of Ian's thin 3/4" rip blades works well on the Basato 5.

Cheers
Steve

 

[OldWood]

Steve, your DVD's are marvellous (!) (hammer) , and your translation of my comment is correct; I should have kept my mouth shut. But that is being a member of a club for you - but I have less qualms about getting my money's worth when I put maintenance time in.

I take it 'Ian' is Tuff Saws? I'm pretty sure that the blades come from the local saw doctor, whose business will be with professional users with bigger heavier machines.

Many thanks for your replies guys - I did think of PM'ing Steve but felt this was a query worth being in public domain.

Rob