Band saw wheel balance

[petertay15]

My old Craftsman bandsaw shakes a little, because the lower wheel is out of balance. The upper wheel can be balanced because it is on a freewheeling bearing, but the lower wheel, mounted on the motor shaft, can't be spun by hand. I tried using one of those little cones used to balance lawn mower blades, but it's not sensitive enough. The lower wheel needs to be dynamic balanced in order to properly place the counter weights. The saw works fine, just bothers me that it shakes.

How would you do it?

[MikeBob]

If a direct drive off the motor, you dont know if it is the wheel or the motor, mine had a belt from the motor to the wheel so I could separate the 2 and figure out what was causing it.

[texaswally]

You might try some of those stick-on weights used to balance ceiling fan blades, would have to be trial and error.

[barryvabeach]

You can dynamically balance either wheel.  First, you need data -  I use a dial indicator attached to the bandsaw table, with the indicator point touching something else - like a wall or a nearby table -  that way, when the BS shakes, you have a measurement of how much   ( needle usually jumps quite a bit when the bandsaw is running, but you just want to note the rough amount of jumping -  so you can see if what you did makes is better or worse.)  Start by putting blue tape, or even a magic marker mark, on one point on the wheel - add a temporary weight, then start the saw and write down the range of movement of the DI, then move the weight to the next spot on the wheel and record the results.  Keeping doing it till you go around the wheel, then put a fixed weight in the spot you recorded as best, then repeat the exercise to see if you need another weight somewhere else.
As for temporary weight, it depends on the size, material, and weight of the bs wheel.  If the wheel is cast iron, a super magnet is a great temporary weight.  If it is aluminum, you might want to try a coin attached with duct tape.

[AUswimKC]

To check wheel balance I always just spun the wheel. If it stopped with the same point down everytime, then the wheel isn't balanced. Usually the heavy spot is at the bottom. Then you add weight to the top and spin again. Some people drill into the wheel. I added washers and nuts with tape. Then, once balanced, I epoxied them to the wheel

[ruffcutt]

Why can't you take it off the saw to balance it?

[jteneyck]

Why would a wheel go out of balance?  It seems more likely to me that something else is responsible for the vibration you're getting.  When I left the tension on my Delta for long periods of time it would intermittently shake like crazy.  After I released the tension and let it sit overnight it was fine, and has been ever since as long as I release the tension after each use.  The tires must have stretched when I left it under tension.  

Vibration could also come from the motor, belt, or bearing.  Setting the tension too high on a wide blade might do it, too. 

Does it shake with no blade on it?  If it doesn't then most likely the problem is not related to the lower wheel.  

John

[Stytooner]

Is the wheel running true? Turn it manually to check that the wheel is flat and running true. You have to check that before attempting to balance it. Could also be out of round due to the tires being worn or improperly installed. Tires can develop hard and soft spots depending on the material and age. A dial indicator with help with all these tests.

[Bill Schneider]

I used the dial indicator method first mentioned above by barryvabeach. I had an older Craftsman bandsaw that shook so badly you couldn't see the cut-line when it was running. After balancing, I could stand a nickle on its end while it was running.

The steps that I used are outlined here:

http://wiki.vintagemachinery.org/Bandsaw...ncing.ashx

[Steve N]

How would you do it?

I'd tear it all down, and rebuild, but not adding any new parts, just cleaning all the sawdust clogs out, and applying some basic lube. After that:

Check the tires, are they broken, cracked, or otherwise not sound?

I would remount the blade if the tires were ok, if they weren't first replace them.

I would make sure the upper wheel tracked true, if it did I would tighten down the blade. Make sure to reset you blade guides, to the dollar bill thickness, and make sure the blade would freely run, by simply turning the upper wheel. Look for any wobble, if there is any your problem IS mechanical, or poor adjustment. It's easier to readjust, than replace everything, start there. Once you have the blade on, and can freewheel the saw without anything hitting, or making noise I would move along.

Now here is the part where I may take some heat, but I would then run the saw, and observe the upper wheel, and the tracking of the blade on the wheel. I'm sure someone is going to say the blade will fall off if you run it without the door closed. That isn't true, and doors on bandsaws are a more recent addition.

If it does all that I think you will find you also really acquainted yourself with your BS, and that you problem is also gone. BS sounds are usually from 2 categories, dirt buildup, and poor adjustment. Both easily fixed.

Good luck