Bandsaw Blade Jumped

Re: Bandsaw Blade Jumped

Keith Newton

I don’t know about your particular saw, but some have some fairly light cast parts that can break. Before urging the blade back on, I would grab the to wheel and try moving it around, rocking side to side, up and down to see if there is any play that reveals a cracked or broken part.

If nothing there, check the bottom wheel to make sure some tilt adjustment bolt hasn’t come loose.

Re: Bandsaw Blade Jumped

John K Jordan

Yikes!

Are the wheels/tires crowned? I'm not familiar with that saw (I've never even seen one) but my bandsaws with crowned wheels are designed to keep the blade in one spot. (I put it in the center of the crowns, both top and bottom) The back of the blade should only contact the thrust bearings when making the cut and even then, very lightly. Is that they way yours usually runs?

Your experience sounds very odd. Did the blade come off the front of the wheels this time?

BTW, in my experience it is difficult or impossible to straighten bends in a blade so it will cut well. It may vibrate or "thump" and make an uneven cut. Might be time to get out the spare blade! Mount and run it without the guides to make sure it stays in one place on the tires before adjusting the guides.

If you don't have a spare blade but have an old, dull blade, it's not too hard to sharpen. I usually sharpen several times before getting out a new blade.

JKJ

Re: Bandsaw Blade Jumped

Don Stephan

Blade came off the back of the wheels. I checked pretty thoroughly yesterday before leaving and didn't find any damaged or loose wheels. I'm sure the blade will not run perfect, but I want to finish cutting out some turned lidded box blanks, and rough them out, today or throw the remainder of the slab out. Have to get to the next project. If the blade cuts a slightly wider kerf it's okay since the square blanks will immediately be turned round. If I had a new green wood blade I would install it, but the length is not one of the common ones so the blades have to be ordered and shipping takes about a week.

All the guide and thrust bearings are set just ever so slightly off the side or back of the blade.

If I had been cutting a curve I could see perhaps the blade was accidentally pushed to the side and slid off a thrust bearing but I was making perfectly straight cuts.

Thanks for the comments. Puzzling.

Re: Bandsaw Blade Jumped

Philip Duffy

Did you check that the proper blade tension was set? Did the tension apparatus break down somehow? P

have one made locally?

John K Jordan

>>>If I had a new green wood blade I would install it, but the length is not one of the common ones so the blades have to be ordered and shipping takes about a week.

If your blade doesn't work and you don't have a friend down the block with a bandsaw Yyou might be able to get a blade made this morning in your area. I buy mine from a local Lenox bandsaw blade dealer - he can usually make one in about 5 minutes if he has the stock on hand. Take an old blade or just the measurement. I know my saw uses 11'10" blades so I can call and he'll have them made by the time I get there.

This finder link will show you dealers. I see several in your area listed as certified Lenox weld centers.

https://www.lenoxtools.com/FindRetailer/FindDistributor.aspx

These places cater to commercial/industrial users so they might have the blade stock on hand. The one I use here usually has what I use, 1/2"x4tpi but last time I had to wait a few days to get 1/2"x3tpi which I prefer for 12" thick stock.

Another benefit of getting blades from my local dealer is they are usually cheaper than elsewhere, sometimes by $10 for the flexback blades I usually get. (I usually buy 5-10 at once which lasts me a long time) I just bought a carbide blade from him and it was 30-40% cheaper than I found elsewhere.

A third benefit is if one breaks he can fix a blade quickly. I've only had one break and got a bend in the process making it unusable but since it broke at the weld he replaced it for no charge.

JKJ

what about the blade tooth configuration

Keith Newton

It seems hard to conceive how it could go off the back if the guides are ok. I’m wondering if it might have come off the front, but ended up behind the wheel after jumping.

If you are using a rip tooth with a positive hook, it can climb into the wood when cutting across the grain.

Re: Bandsaw Blade Jumped

Don Stephan

Re-installed the blade and looked at all the guide bearings which are Carter aftermarket. The lower thrust bearing round side faces the blade, and the blade was only catching about 1/16" width of that round face. Moved the lower thrust bearing over another sixteenth. To finish cutting out the rectangular lidded box blanks only took about 8 minutes, so it wasn't much of a test, but I had no problems. Thanks all. The varied observations and comments made for a very thorough discussion.