Sealy horizontal bansaw

Hi guys ,

having problems with the band saw throwing off the blade. I've tried running pulley to pulley without the guides and it still happens .whichever way I try to adjust I get the same result. I did try the blade upside down and it did stay in place for a few minute's before coming off.

Do you think the blade could be distorted ? or do you think its down to adjustment.

Both pulley wheels look ok and seem to be running true.

Thanks

Bob

more info.....

what machine and how old is it ?........

could be anything from wrecked bearings to miss alignment....did it suddenly happen ?

but miss alignmet does happen suddenly, it can happen after a rebuild or major repair......

a photo or 2 may help.....my 12" bandsaw is prob now 16-18 years old and has never thrown a blade.....

snaped a few but thats normal.....

hope this helps a bit......

If it's the same version as mine, the 6 inch capacity simple one with a 64+1/2 inch long 1/2 inch wide blade, then my experience is that once the blade has come off it'll never run true again. However before fitting another blade, check the wheel alignment with a straightedge in two planes just to see they're somewhere handy.

Unless something has changed (bearing collapse, frame twisted or something major - but if so why is it not obvious) then you should be able to get the new blade to run in the correct position reliably just with the two wheels aligned by eye. . Twiddling the blade alignment screw (tracking adjustment) from this initial visual wheel alignment shouldn't make the difference between keeping the blade on and having it jump off, though it can make the back of the blade ride up the ridge on the wheels and that ruins the blade. Guess how I know!

The blade should run with the teeth off the front of each wheel - I've found if you let the blade ride onto the wheel too far you iron the set off the one side of the blade and then you're on a hiding to nothing.

HTH Simon

It might help you to have a look at this guide to setting up a bandsaw - **LINK**

It's American so refers to "Harbor Freight" but these bandsaws are all of a similar pattern.

When it threw the blade off it may well have caused a kink, so it will never run true. Try it with another blade when you have set it up.

A small built up layer of debris can cause your problem if it is the type with plain metal wheels (no rubber tyres). It can sometimes be cured by cleaning the wheels with emery cloth. Colin

Check the two wheels that includes the bearings have not worn. Clean the tyres if it has some and check them also for damage. When setting up the blade make sure it rides in the centre of the tyre this will keep the blade in the correct orientation for a square cut also make sure the guides are correctly set. As already stated try a new blade in case the old one has distorted. I may not be a model engineer yet but have had experience with bandsaws in general as I own two and run them both with no problems. Using mine for wood I quite often change blades for a specific job as I cut tree trunks with one of the blades

Don't be afraid to adjust the tracking (i.e. angle of the wheels not just lining them up) - 99.7% of bandsaw owners don't even know they CAN adjust it!

Neil

I had this fault, the problem was in the tilt of the top wheel.

You think you have taken all the available tilt to keep the blade on, but you have actually misunderstood how stupid the tilt mechanism is. There is no pivot, there are only screws. You have to loosen the two to get more tilt from the third.

Take it apart and have a look. After years of my blade coming off it is now never a problem (Touch wood).

Ok final report and thanks everyone for your help.

I stripped down the guides ,cleaned and realigned fitted new blade and set up for square. Result it is now cutting without throwing the blade and is within 2thou on both axis. Took a while with final tweaking but well worth it.

One happy bunny.

Thanks again for your help.

Bob

Just throw this in here whilst i think of it.

They are all the same heads just the bases are different.
If it starts chewing up the blades suddenly replace the 6 guide bearings with cheapies about £3 for 10. Line them up on the eccentric cams and good to go.