Here’s a simple question with a perhaps a difficult answer. How do you balance a bandsaw wheel? Mine appear to be unevenly weighted. When I take the blade off, the top wheel rolls down into the same position no matter where I start it from and the band saw does have a shake to it when running. Perhaps when I get the tire off it will turn out to have been the problem. But in case its the wheel the only thing I can think of is to balance it on the point of a cone and then file off metal from the side that appears heavy. Will this work?
Andy
Replies
That should work, but depending on the severity of the imbalance, you may also try using a drill press and drill a series of small divots along the heavy edge to remove material. This is an old solution commonly seen on large wheels and pulleys used on old farm machinery. But be careful, you can remove more weight than you think you are real easy this way.
Yes, a very simple solution. Sometimes I think my brain just doesn't work anymore.
Thanks.
If you have or can get lead tape, you can add a little at a time, diametrically opposed to the heavy spot. It will also keep the wheel from becoming lighter, which isn't needed since they're made of aluminum. Always good to save a bit of momentum.
"I cut this piece four times and it's still too short."
highfigh-
Good point about momentum. I was intrigued by your idea about lead tape, I have heard that for ceiling fans, but not machinery. You piqued my interest enough that I played with the idea this weekend. (too much time on my hands, I know)
In Andy's case, lead tape will probably work if he needs less than, say, 2 grams or so.
For the benefit of anyone else reading this with a similar problem. The following may be helpful:
Depending on the amount of weight needed, and the diameter of the wheel, I may not trust the adhesive on the lead tape, especially taking centrifugal force into account. If the tape can be placed on an inward facing surface, no problem, tape away, however, on both of my bandsaws the only surface flat enough to stick something like that is the edge of the rim, which would put lateral force on the adhesive.
A 5 gram piece of lead, moving in a circle at about 3300 fpm, would apply about 1.77 pounds of lateral (shear) force to the adhesive. I did a quick experiment in my shop to test the effects of this:
I attached a 22 oz (1.375 pounds) framing hammer head to a piece of string, that I then taped to the edge of my band wheel. I did not have any lead tape, so I used small pieces of several kinds of tape (duct, gaffer's, carpet)I did have, assuming the adhesive on the lead would be similar to one or more. None of them stuck for longer than a few minutes. Combine the effects of time, and maybe a hot summer day to that tape, and you could be flinging lead around in your wheel housing. Granted, not really dangerous, given that 3300 fpm works out to about 35mph, but if you are in the middle of a cut, it could startle you.
Of course, if Andy's bandsaw was out of balance by 5 grams, it would have walked out the door and down the street long ago. ;-)
my $2.02
Tony
Someone mentioned tire weights. These have a steel clip to hold it onto the rim and since most bandsaws have ribs, a weight like this could be clipped on, crimped if necessariy. If there's too much weight, some can be removed. If too much is removed, some can be reattached.
"I cut this piece four times and it's still too short."
That would work.
Do those weights come small enough?
They come in assorted wieghts, but I don't know what the smallest one is. Like I said, if the smallest is too much, some lead can be removed.
"I cut this piece four times and it's still too short."
Andy,
When mine was new (seems eons ago), I balanced the wheels in place by drilling progressively deeper, 1/4-in-diameter holes in the wheel's thicker rim - blade and drive belt off. After drilling some, I slowly spun the wheels and noted where they stopped - the heavy sides down. I drilled some more until they stopped at randomly different places. Then they were balanced enough and ran vibration free.
Hope this helps.
Gary
http://gwwoodworking.com/
Edited 2/17/2005 10:44 am ET by Gary
Hello Andy. I would try going to a tire store and purchasing some of their smaller weights for balancing car tires. There are stick on ones and there are clamp on ones. This way you can screw up and not make things worse. Peter
Thanks for the advice. Here's another problem (I didn't know that you were supposed to detension the blade after use. Mine's been tensioned for four years now). My blade is also drifting back and forth about 1/16th of an inch between my guide blocks. I guess this is bad according to what I've read. My hope is that my tires simply have a real bad flat spot on them. I've got new tires.
So, I guess I need to first check my wheels to see if they're warped. If they are, does anyone mill these to true them up or do I need to find new wheels?
Also, should I balance the wheels with the tires on or off? I don't know if the tires are evenly balanced themselves.
All of these questions are the result of me needing to resaw some 6" lumber for bookmatched panels which my saw is not capable of doing right now due to the shake and wobbling blade.
Andy
I would say balance with the tires on since that is the way you will run the saw. If you balance before and then the tires are not perfectly even or there is more glue in one spot than another all that work will be for naught. AndyE
Could you provide a little more detail about the "drifting"? Do you mean to say that it "throbs" rhythmically? On which plane? In and out, towards the throat? Or back and forth, in line with feed direction? if it is the latter, your blade is probably welded crooked. I have had blades do some pretty strange things, so go out and get a good blade, first. My personal choice is Timberwolf silicon carbide. They are low tension, and the package has tensioning instructions. They are awesome for resawing. I used one to slice Quartersawn slats out of a piece of 8/4 plainsawn white oak for a mission crib I built for my daughter. Like a hot knife thru buttah.:-)Tony
Back and forth from side to side. I checked last night and either the the tire or wheel has a bad flat spot.
I'll change the tires and go from there. I've also got the timberwolf blade and am sure I will be very happy with it if I can get my bandsaw tuned up.
Andy
I wrapped 10ga copper electrical wire around the spokes of the saw wheel. They hold tight, are easy to work with, and are readily available. I had a lot laying around the shop form wiring outlets. I read about this on diy.net
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