Bandsaw frustration

[Mike Bayerl]

I have a '90's era US made Delta 14"with riser block and it's worked well for me for many years. Then, the other day, the blade ran off the bottom wheel when I was using it. I fiddled with it for over an hour yesterday to get the tracking, etc. all back in order and I got it running just fine. Then, today it happened again. Now, I've just trashed two very nice (i.e. expensive) bands. :mad: I'm not sure where to go from here. Any advice?????? My copy of Lonnie Bird's Bandsaw Book is out on loan to a friend right now. Any links to step-by-step re-alignment, etc.?

[John Lanciani]

If the tires are the original orange ones I would start there. Delta didn’t glue those tires on from the factory and as they age and lose elasticity they start lifting off the wheels and causing the problem you are having. My personal preference is for black rubber tires glued on and crowned to the wheel, others will recommend urethane just slipped on.

[glenn bradley]

Tires would also be my first guess as well. I'm not sure why the blade is getting trashed. In my experience if a blade goes off the wheel, it just stops. Is something getting caught up in the works somehow?

[Mike Bayerl]

If the tires are the original orange ones I would start there. Delta didn’t glue those tires on from the factory and as they age and lose elasticity they start lifting off the wheels and causing the problem you are having. My personal preference is for black rubber tires glued on and crowned to the wheel, others will recommend urethane just slipped on.


Tires would also be my first guess as well. I'm not sure why the blade is getting trashed. In my experience if a blade goes off the wheel, it just stops. Is something getting caught up in the works somehow?

Thanks for the responses. Tires are in good shape, Carter blue ones and only a couple years old. Saw only gets a dozen or so hours / year.

T

[Mike King]

Are you running too much tension?

[John TenEyck]

OK, tires are good. If so, I'd be looking at where the trust bearings are set and how much tension is on the blade. If those are good I'd look at where the blade sits on the lower wheel when centered on the upper wheel. Maybe the wheels are way off from being coplaner.

FWIW, the only times I've had a blade run off the wheels on my Delta it was because the tires were loose. Constant tension caused them to stretch.
John

[Mike Bayerl]

Thanks. I need to double check coplaner, etc. The last blade I ruined was a Timberwolf low tension, so I was running a little below what the guide on the saw recommended.

[Mike Bayerl]

I'm not sure why the blade is getting trashed. In my experience if a blade goes off the wheel, it just stops. Is something getting caught up in the works somehow?
Teeth of the blade hit the steel on the guard, lots of sparks, very ugly.

[glenn bradley]

Teeth of the blade hit the steel on the guard, lots of sparks, very ugly.

Yikes! So the blade started to hit things while it was still being driven. That does make you wonder about guides. But, did you recently change blades or was the blade operating OK before and then fail on the last use? We're obviously looking for what changed here.

I'll relay an experience with Dad's cast iron 14" with jumping blades. He lives a few miles from the coast and some plastics and rubbers will provide service for extended periods and then just lose integrity suddenly. Tarps will disintegrate, plastic bins will crumble, etc.

We were at our wits end with the blade jumping off the tires until we happened to run the saw with the covers off. You could see the tire malform under the stress of startup and actually leave the wheel surface. A moment after full speed was acquired, the blade would jump off.

When not running, the tires seemed fine. They only misbehaved under load. Since you have a "dead" blade you could pull the covers and back off the guides and try this as a next step with a known history of occurrence. New tires solved his issue.

[andy bessette]

...My copy of Lonnie Bird's Bandsaw Book is out on loan to a friend...

Borrow it back and go over the saw step by step. You'll find what changed.

[Van Huskey]

I'm reticent to post this (will explain in a second) but Alex provides a useful guide to setting up a 14" cast saw.


https://www.youtube.com/watch?v=wGbZqWac0jU&t=2s


Why am I reticent? I don't agree with several theories he presents, the information is also not as universal (to all saws) as he makes it seem. That said it is a good visual setup for a 14" Delta or clone saw despite the fact I would approach some things differently.


Once you have correctly setup the saw to rule out setup issues if it happens again you can attack the more mechanical issues. Tires are certainly a potential issue.

[Chris Parks]

I would check the main wheel bearings and all the bracketry that the wheels rely on to keep them in place. Sometimes a bracket or fixture can break on some saws.

[Bob Vaughan]

We were at our wits end with the blade jumping off the tires until we happened to run the saw with the covers off. You could see the tire malform under the stress of startup and actually leave the wheel surface. A moment after full speed was acquired, the blade would jump off.

When not running, the tires seemed fine. They only misbehaved under load. Since you have a "dead" blade you could pull the covers and back off the guides and try this as a next step with a known history of occurrence. New tires solved his issue.

This is a typical cause of problems with the Delta 14" band saw wheel design. Good rubber would last a long time, but still loosens up after a couple of decades of use if they were not glued on. Poly tires are worse for loosening up if they aren't glued on. The slip-on tire idea gives the user the hopes of easy maintenance, but its not without its long term problems.

Also, the crown can wear down over time and create tracking problems. True, Delta wheels are pre-crowned and that seems to promise that no crowning is required. That's not always correct either. The Delta wheels had profiles that varied over the years thus making some tires fit better than others.

Assuming tires will be the same thickness once mounted on the wheel is a risky assumption. There are always high and low spots some tires worse than others.

My years of experiences with these saws (and Asian wanna-bees) had resulted in my concluding that for 100% satisfaction, use rubber tires, glue them on, and then machine crown the tires on the wheels.

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[Bill Space]

...I'll relay an experience with Dad's cast iron 14" with jumping blades...

...When not running, the tires seemed fine. They only misbehaved under load. Since you have a "dead" blade you could pull the covers and back off the guides and try this as a next step with a known history of occurrence. New tires solved his issue.

I am with Glenn on this. Recently my old 18” Grizzly bandsaw started to make a thumping sound, like the weld on the blade was failing. The blade was new and the rubber tires looked like new, although the saw is probably over 20 years old. Maybe (gasp) 30?

Anyway, I took the covers off and ran the saw, and it was immediately obvious a tire was lifting off the wheel. Don’t remember if it was one tire or both. I glued the tires to the wheels, and the problem disappeared. The tires looked like new.

So I learned that just because tires look new, that doesn’t mean they are like new...

My issue started after after putting a narrower blade on the saw. The one that came off was twice as wide and must have been holding the tires to the wheels.

Bill

[Mike Bayerl]

Thanks for all of the constructive feed back. As soon as I have some time, I'm going back to basics to see what could be the problem. I will let you all know if I figure it out and/or if I need more help. Stay tuned. Same bat-time... Same bat-channel.

[Mike Bayerl]

Ah hah! I figured it out. There was nothing actually wrong with my saw. The last time I released the tension I went a little too far and the nut that compresses the spring (see pict) got out of it's fixture and when I tightened it again it jammed on the bottom of the fixture instead of riding up into the fixture. This caused the upper wheel to go way out of line as I tightened the screw. Once I figured this out, I put on a new band and it tuned right up perfectly. No new tires, no new bearings, no other adjustments. Phew!
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[Mike Bayerl]

Thanks again everyone!!!

[Ken Fitzgerald]

Mike, thanks for reporting back what the cause was. Others will find this useful in the future!