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Bandsaw throwing off 1/8" blades

Posted: Sun Nov 17, 2013 3:50 pm
by danr
I followed another thread until it petered out in 2011 with no resolution so I thought I should start a new thread.
Problem: 1/8” blades walking off wheels
Mark 7
New SS bandsaw 2013, less than 25 hours usage
Works fine with ¼” blades
Worked previously with 1/8” blades

Install new 1/8” Bosch blade 72 7/16” and set tension as spec. Run machine @1000 rpm and blade jumps off wheels. Reinstall and run disconnected by hand. Blade migrates from back away from guide bearing toward front. See photos attached.
From the other thread, I suspect that the cant on the upper wheel is not correct but I am not about to try bending any of those castings.
What can I do? Why is this thing throwing off blades?

Dan

Posted: Sun Nov 17, 2013 4:20 pm
by dusty
Here is an extractfrom the Bandsaw Manual.

Your problem might be that you are pushing the operational parameters at that speed. Technically, 1050rpm is within the parameters but you are right at the limit.

That said, since this is a new bandsaw, I suggest you contact Shopsmith right away to see what they recommend. If it was an older bandsaw, I would suspect the cant on the upper wheel is wrong. The cant is not adjustable. You get what you get.

If you back the speed down to say 600rpm with an 1/8" blade, what happens.

Posted: Sun Nov 17, 2013 5:28 pm
by rcplaneguy
I'd check the tracking roller bearing, but I'd also order a 1/8" blade from Shopsmith.

Posted: Sun Nov 17, 2013 5:34 pm
by rcplaneguy
Tracking roller bearing correctly aligned? Would be fun to test with a 1/8" blade from Shopsmith.

Posted: Sun Nov 17, 2013 5:46 pm
by danr
I will contact SS. However, the photos were taken after manual rotation.
I didn't state but I also tried slower speeds and different tensions to the same result.
Wrong cant make sense to me but why did it work with a 'used' blade, one last used on my, now sold, 1998 model.

Posted: Sun Nov 17, 2013 5:50 pm
by danr
The tracking roller is not exactly aligned. However, I cannot see how that will make any difference because the blade does not stay in contact more than 1/2 wheel revolution. It begins to move away immediately.
Dan

Posted: Sun Nov 17, 2013 5:51 pm
by rcplaneguy
d.rositer wrote:I will contact SS. However, the photos were taken after manual rotation.
I didn't state but I also tried slower speeds and different tensions to the same result.
Wrong cant make sense to me but why did it work with a 'used' blade, one last used on my, now sold, 1998 model.
That's why I suggest an original Shopsmith 1/8 blade. I bet that is what SS will ask you to do next.

Posted: Sun Nov 17, 2013 5:52 pm
by nuhobby
Just throwing this out (no pun intended).... I have never used a blade quite as long as yours. I've either used 72" exactly or slightly less.

Posted: Sun Nov 17, 2013 6:52 pm
by rcplaneguy
I've heard of bad welds on some brands of blades causing tracking problems. Inducing tracking problems, etc.

Posted: Sun Nov 17, 2013 6:55 pm
by rcplaneguy
Maybe a bad weld on the Bosch blade?