Replacing Bandsaw Tires

Replacing Bandsaw Tires

by Robert Feeser

This article first appeared in a thread on theWoodNet woodworking forum. It was compiled and reproduced here for easier public consumption. All Text are the property of Robert Feeser.

This was for rubber tires on a 14" bandsaw, I believe. Most of it should be equally valid for the urethane tires, I think.

Handed out as part of bandsaw tuning talk given in two sequential meetings of the Greensboro Woodworking Club in summer, 2005. Note that I probably had only 45 minutes at each meeting.

REMOVE THE WHEELS

First, mark the front rim of both wheels so there will be no confusion about which way to remount them. Then remove the wheel.

HOW TO MOUNT AND TRUE TIRES

The tires can be stretched over the wheel by hand without much trouble.
Take the wheels off the axles first to avoid stressing the machine.
- The tensioning and tracking mechanism can be broken without too much effort. If the belts are very hard to get on, it can help to put the rim of the wheel on the floor, engage the tire first at the top of the wheel, and then press both sides of the tire down toward the floor, using your weight to help. If necessary, you can also lever the tires on with screwdrivers like you do with bicycle tires, but that can cause some minor damage. Immersing the tire in very hot water for a while softens some tires, making them easier to stretch onto the wheel.
The next step is adjusting the tension so the tire is close to perfectly round to minimize vibration and other motion.
Unfortunately, this can be a tedious affair. I have spent well over an hour on a tire. I have had difficulty improving the roundness of the tires much with a pair of urethane tires, but it worked quite well with two pairs of rubber tires I have mounted.
The tire is a rubber or neoprene band stretched around the wheel. When you stretch the tire onto the wheel you end up with varying tension, and therefore varying thickness, on different parts of the tire. To get rid of the high and low spots you have to push and pull the tire around the wheel to redistribute the tension and the rubber. Place the wheel on the axle and spin it. Watch the outer edge of the tire and locate the most severe high or low spot. Then remove the wheel and stretch the tire away from the high spot or toward the low one with your hands. Then work the edges of the tire down into the groove in the wheel, making sure it is seated well. Press with your four fingers against the opposite edge of the tire rather than with your thumb against the near edge. The four fingers are stronger than the single thumb. Mount the wheel and spin it again, checking your progress.
Be patient and keep at it until the tire is as round as you think you are going to be able to get it by eye.
On one tire I tried to equalize the tension around the tire by inserting a dowel between the tire and the wheel and then rolling the dowel along the rim of the wheel, all the way around several times as Mark Duginske's book recommends. I still had to work high and low spots out of the tire manually. I also tried using a metal rod instead of the wood dowel; same result. I skipped that step on the other tire and could not tell that the process took any longer.
To improve your ability to locate lumps and dips, clamp a wood stick to the cabinet so the end comes very close to the crown of the tire. Spin the wheel and keep tapping the stick in a tiny bit at a time until it just touches the biggest high spot-you can hear it rub. Remove the wheel and work the high spot out by shifting the tire away from it slightly in both directions, then check it again. Keep working at it until you don't think you can get it any better. Let it rest overnight and then try again.
When ready to check roundness, you can measure the amount of runout with a dial indicator. Mount a wide blade, tension it properly, and position the dial indicator to touch the side of the blade somewhere where it lays on the tire rather than to the rubber tire itself. It works better and is more accurate because the metal blade provides a smoother surface for the tip of the dial indicator, and it's really the roundness under a properly tensioned blade that counts.
If there are significant variations, verify that you are not measuring variations in the thickness of the blade by turning the wheel several times and noting the position of the highest point each time. It should appear at the same point on the wheel each time. If it doesn't, your measurement is being thrown off by uneven blade thickness or a kink or twist in the blade.
Lonnie Bird's book says that a tire out of round by only 0.025 in. will produce a noticeably rougher cut.

HOW TO MOUNT WHEELS - WHICH SIDE FORWARD?

Remount the wheels with the marks you made on the rims to the front.
If you forgot to mark the front edge of the wheel, or the mark has disappeared, this may help. The wheels usually have one or more little balancing divots drilled in one side-shallow holes drilled with a normal drill to lighten an area of the wheel's circumference that is heavy. Mount the wheels on the old blue 14 in. Jet bandsaw with the balancing divots facing the back. That's the way they came on the saw. This is important on the lower wheel-mount that wheel backwards and it won't turn when the center bolt is tightened-but shouldn't matter on the upper one.

Return to Power Index

Return to Woodworking