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band saw crown questions

I recently mangaged to score an old W. F. Wells 7x11 bandsaw.

Nice machine but it was set up for a 1/2" blade and I am converting it to 3/4".

This leaves me with a "How to crown the wheels?" question. I am kind of surprised at what's there right now.

Here's a cross section diagram which should help understanding the setup:

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Where I would have expected a crown of a few thou, it's negative by 2 thou!

The fact that there's a shoulder that the bottom of the blade rests against may be doing something strange to the set up. Or maybe some other "smart guy" made some changes and didn't understand the point of a crown. When I bought the machine the blade was on backwards!!

My plan now is to turn the wheels so that they accommodate a 3/4" blade and leave a crown of 3 or 4 thou.

Sound right?

Tanks, DOC

Reply to
doc
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Nope---no crown. The wheel is adjustable to keep the blade running

*lightly* against the shoulder. They do not rely on crown.

The larger blade will also be thicker. It may not enjoy the tight radius of the small wheels and die from fatigue prematurely. I'd appreciate hearing how it performs when you get it done.

Harold

Reply to
Harold and Susan Vordos

Yeah, I discovered that this weekend when I changed the blade on my saw for the first time. Had a devil of a time getting the blade to stay on. It would run fine until I put it under load and then it would pop off. I think I finally got it to work. Any advice on how to make the set up quicker and easier? Thanks

Reply to
Kelly Jones

Not to contradict anyone, but a "Biro" meat cutting bandsaw using metal wheels without any "tire" of any kind uses about a 2 degree slope (higher toward the back of the wheel) to make the metal blade "climb" up to the back of the wheel. Both the bottom wheel and the top wheel have to be tilted a little bit to compensate....and both wheels are made the same. There are small "grooves" that run around the perimeter of the wheel, where the blade tracks. Ken.

Reply to
Ken Sterling

The answer to this and every other question I've seen posted about bandsaws can be found in the excellent and often-referenced book "Band Saw Handbook" by Mark Duginske. Full retail price is about sixteen bucks as I recall. Excellent book.

GWE

Ken Sterl>>snip---

Reply to
Grant Erwin

Sorry to say, none. I bought my Wells A7 new back in '67 and it's worked without problems for all that time aside from having to replace the motor when it seized.

As I recall, there's some adjusting screws under the drive wheel cover that tilt the wheel such that it causes the blade to run against the shoulder. If I'm not mistaken, the blade will climb to the high side, so tilt the wheel slightly downward should cause the blade to climb. I'd be interested in hearing what you've done, and what worked.

Harold

Reply to
Harold and Susan Vordos

While bandsaws do not use crown, for any application that does, refer to machinery's handbook, there is a detailed section on crowned pulleys.

Reply to
Jon

Jon, I have a Sears 12" woodcutting bandsaw - it is crowned, with a rubber tire. Ken.

Reply to
kws2003

Not much more than trial and error. I adjusted the wheel (adjustments were under the idler wheel in this case) and turned the motor shaft by hand ans watched the response of the blade. I made adjustments until the blade just touched the lip of the wheel and then tried it. It kept popping off and soe I increased the setting in the same direction a few more times until it quit popping off. This method just seems too hit and miss, but it was all I could figure out at the time.

Reply to
Kelly Jones

Hey, what ever it takes to achieve success. Thanks for the report, which could come in handy some day!

Harold

Reply to
Harold and Susan Vordos

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