static wheel balancing
You have to wonder who designs this stuff. Team Associated seems to be mighty popular in the RC hobby scene, but it seems one is paying more for the name than for proper engineering.
The Team Associated Handheld Universal Tire Balancer works fairly well, but only after you correct what the designer screwed up. Here's what to do:
- Stick a hex driver in the hole at the back of the handle and remove a small socket head cap screw. In my case the hex size was the same as for the long set screw used to hold the wheel assembly on the front end of the balancer (where you thread the cone on) - 0.5 mm i think.
- Pull the assembly apart to expose the bearings.
- Carefully remove the bearing dust seals (not the metal shields). I don't recall if i had to pop the bearings out to see the seals, but the dust seals in my case were blue in color. They are basically just flat washers with some sort of rubber-like coating. You can pry them out with something like an X-Acto knife or a very sharp pick. Carefully work the tool between the outer bearing race and the dust seal and gently pry out the seal without damaging the other bearing parts.
- With a solvent or hot soap and water, wash all of the lubricant out of the bearings and dry them.
- Re-assemble the tool with the metal shielded sides of the bearings facing outward (away from each other). Do not lubricate the bearings!
This little mod will achieve a much more accurate wheel assembly balance because it greatly reduces the rotational friction created by the dust seals and oil used in the bearing. In my case this tool was 90% useless when balancing a small 3 in. wheel until i applied this mod.
Lastly, if you're really particular, know that this balancer will not work as well as something like a prop balancer, although the larger and heavier the wheel, the better it will work.
To balance wheels, forget what the instructions say. Here's how i do it:
- Mount the wheel assembly (rim and tire) on the balancer and, holding the tool level, let the wheel come to rest. Be careful not to touch the wheel assembly or the insert at the back of the tool with your fingers because it too rotates. Rotate the balancing tool handle back and forth just a wee little bit once the wheel stops in order to achieve as accurate a result as possible using this kind of balancer.
- Make a mark on the top of the rim (the lighter side of the rim). This is where weight needs to be added.
- Cut a piece of balancing weight and using a very small piece of tape (masking tape works well), center the weight on the mark and fasten it temporarily to the rim in the same place and position as it will be placed permanently later on. I like to add the weights on the inside of the rim nearest the spokes. You can use solder for wheel weights, but that self-stick lead tape is easier to work with and does a nicer job, just don't peel the backing yet. If you're using solder, you could pound it flat to emulate balancing tape and make it easier to attach later on.
- Keep removing or adding weight until the wheel assembly is balanced. To check for proper balance, the wheel assembly should not rotate regardless of what position you put it in, so you want to rotate it to several (at least 4) positions and check that it remains there.
- Affix the balancing tape or solder to the wheel in the same spot as where you temporarily placed it. Solder can be affixed with an adhesive or a thin double-sided tape.
dynamic wheel balancing
There is another alternative that should be even more accurate than using a static wheel balancer and it costs nothing, however it only works for the powered wheels. I'll describe this without using images because... because i'm being lazy and because you're smart enough to figure out what we're doin' here.
- Put your vehicle on stand or blocking of some sort to raise the wheels off the work surface.
- Power the system on and provide enough throttle to spin the wheels at a slow to moderate speed, just enough to get the wheel to vibrate if it's out of balance. It would be easiest to increase the throttle using the trim so you can have both hands free.
- Using a magic marker/pencil/crayon/bloody finger/etc., very carefully move it into the rim, towards the wheel nut, and then downward until it just barely comes into contact with the inside of the rim.
This will leave a mark on the light side of the rim and wheel assembly, thus the weight needs to be placed in line with the center of the mark either on the inside or outside of the rim (i prefer the inside so it isn't seen). This dynamic balancing technique should be more accurate than using a static balancer.