Vintage Dynamic Wheel Balancing

Yes in the early 70's as a young man i high school worked in a garage. They had one it had three dials in the center. They moved weight around the wheel to balance it. It did do better job of balancing as it balanced the whole wheel as an assembly not just tire and rim. Took a bit of skill from the mechanic to operate not like the machines today.

Never used one as was explain to me one dial change the weight, one changed the location on the circumference and one move it in or out on the wheel. First you would find the major weight of imbalance and location split the weight and place front and back of the rim. Then you would fine tune by moving smaller amounts weight in and out on the wheel and place weights.

The one I used had 4 little knobs centered on the shaft. Two adjusted the weight. Two positioned the weight around the the axis. You started by giving a slight weight and rotating the weight around until the vibration lessened. then you fine tuned between position and total weight. It took a little practice to get it right, but with practice, you could get a very accurate balance. Not everyone had the patience so results varied by who did the work. They also ran very fast, so they could be dangerous. Most truck shops probably still use them or have them around.

The device you are talking about was a dynamic wheel balancer. The way it works is that it had four rings (bearing like devices) that were used to increase the weight and location of the weight that was required to balance the tire and wheel assy. The first ring increased the weight. the second ring decreased the weight, the third ring moved the weight clockwise and the fourth ring moved the weight counterclockwise. To use the device the tire and wheel would be spun by an electric motor with a drum attached that was applied to the tire through a lever that would press the drum against the tire and spin it to a speed of approx. 75 mph. By moving the dials you can increase the weight and move it around on the wheel until the vibration is negated by the weight. Most people would take one hand and lay it on then side of the fender with their middle finger lifted above the fender and would watch for vibration on the raised finger. By working the dials you could increase the weight and location to counter the out of balance condition of the tire. Once the vibration was gone then you would stop the tire and in a window of the balancer would be a number showing the amount of weight and an arrow on the hub would show you where on the wheel to apply the specified amount of weight.

Hope this explains it to your understanding and it was an extremely accurate way to balance a tire but they quit using these balancers because they were deemed to be to dangerous to use.