Hi all I have a good question for you. Our bandsaw have been working for however many years with apparently the wrong sized tires for the wheels. This was throwing the alignment vertically off, pushing on the arm and burning holes through the throat plates. I set out to have the tool fixed (-$300). It was the end of term so the tool got no use until now when I turn it on the tool does not hold onto the blade at all. There is no way to delicately adjust the pitch to have the blade stay on..plus due to how the tool is configured it is impossible to see if the wheels are aligned.
Has anyone seen this happen on their bandsaw. The repairman now wants to grind of the tires he put on (-$500) and the try to fix it from there (-$200-?!). He has us over a barrel.
Chip, do your tires have a proper crown on them? Flat tire profile doesn't have a natural track for the blade, so the blade wanders. A properly crowned tire profile leads the blade naturally to the highest part of the crown.
Does your blade wheel have a crown under the tire? If it does, the tire should take on that crown profile and the blade should track if the wheels are reasonably in line. If the wheel profile is flat, perhaps it is necessary to grind a crown onto the tire. If that is a standard requirement, I would think the mechanic who replaced the tire should have ground it.
If you determine that grinding is necessary, you can probably do it yourself. It will be messy (rubber dust everwhere), but you could limit the mess by setting up a shop vac to capture most of the dust.
I would consider using an expanding rubber sanding drum that accepts an abrasive sleeve of about 1.5" or 2" and rig up a holder that will allow you to fix the position of the spinning sanding drum relative to the tire and feed it into the rotating tire very slowly. I would not try this free-hand. Feed the sanding drum in for very light cuts and let it "spark out," that is, keep grinding the rotating tire until there is no more grinding taking place, then feed in a small amount again. Run the drum at the highest speed that does not exceed its speed rating and use a fairly fine grit.
I just looked at three bandsaws (an antique Sears toy, a 14" Rockwell, and a
26" DoAll), and they all have a very visible crown on the tire. The two small ones have the crown on the wheel and I didn't try to look under the DoAll tire because it is glued on. Just eyeballing it, the radius of the crown looked to be about the radius of the wheel.
If your tires already have a visible crown then the wheels must be pretty badly out of alignment or might not be secured in position very well. If you push on the rim at the bottom of the top wheel in the direction that the blade tension pushes, does it move noticeably? If so, you will have to find out why. The wheel tilt adjustment screws are usually in the carrier that slides up and down to tension the blade.
Since nothing has changed since the repairman "fixed" it... I think it ought to go back to the repairman for free repairs to make it right.... After all, *that's* what you paid for the first time... Ken.
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