Originally Posted By: The Critic
I wonder if there is a difference in the accuracy of a wheel balance with these higher-end Hunter dynamic balancers in comparison to the ancient Coats machines.
Critic, they are saying that they are targeting a lesser accuracy of balance when measured according to the old method, by defining a new method which uses the tyre/wheel assembly as part of the equation.
The old method works to "ounces" of unbalance, which isn't a metric generally used in industry, where the actual displacement is measured.
As an example, turbines. Shaft vibration amplitude is measured. Anything under 80um shaft movement is pretty well OK, regardless of it being a 40 tonne main turbine rotor, or a 4 tonne auxilliary turbine. If either got to around 100um, we'd look at balancing to get them back under 80, preferrably in the 50s.
The big rotor, we balance with weights in increments of 2/3lb, The small one in tens of grammes...but remember our target is actual running smoothness rather than getting within half an ounce of the "perfect" balance.
IMO, it's kosher, in answering the actual question of tyre/wheel vibration.
All that being said, if the old method gave a more "accurate" balance, and there was no savings as a customer with the new method, I'd take the old.