What size pads are you using? What size backing plate are you using?
The rotation of a PC is driven by the orbital speed. The faster the machine orbits, the more centrigual force is applied to the backing plate (which in makes the pad want to spin). One of the draw backs of foam pads on a DA is that they have a tendicancy to absorb the orbital action of the pad (like a sponge).
Because of this reason using low diameter 5.5 inch pads will really wake the PC up.
Just food for thought...
The power of the machine has *nothing* to do with the pad`s spinning rate (RPM). The reason I *`d nothing is because it obviously has something to do with it, but the effect is very indirect.
What makes the pad spin is the size (stroke) and speed of the orbit. Think of the orbit like a bicycle pedal. The distance from the pedal to the axle would be considered 1/2 the stroke. Since the pedal orbits the axle on both sides, we add the distance together to get the stroke.
And this is why power rating of a machine is slightly misleading. Regardless if a machine has 1 horsepower or 5000 horsepower, if it is able to maintain full OPM (orbital speed) under pressure then it will spin the pad the same rate, regardless of pressure. Granted the 1 horsepower machine will likely be working much harder to achieve that speed (more % of its potential).
The power of a machine can potentially resist how much the speed decreases when friction is applied to the orbital motion. I don`t care how hard you press down on a 5000 horsepower DA, you aren`t going to bog it! But here is the catch, the orbital action (5/16th stroke) is fairly efficient and even under pressure it is hard to slow the orbital motion down. Most of the friction (that stops the pad from spinning) is taken up in the bearing of machine. The only real force acting to bog or slow the orbital speed is the internal flex inside the pad. A firm, thin pad is going to transfer more of that friction (from the paint) directly to the orbital motion where as a oversized squishy foam pad is going to jiggle on itself and absorb the friction. It gets a little confusing (which is why pad dynamics play such a HUGE role in DA polishing) but a big, tall foam pad will stall the spinning easier (since their is more friction at the paint`s surface) but most of that friction will be absorbed by the foam, which can make it harder to stall the orbital motion.
Most modern DA`s are rated at 6800 OPM maximum and most (because of pad dynamics) will maintain that orbital speed under significant pressure, regardless of how much power it has in reserve. Since the pad`s rotational speed is a function of the stroke and orbital speed, if a weak machine and a strong machine both have a 5/16th`s stroke and both are able to maintain a consistent orbital speed of 6800 OPM, the both will spin the pads at the same exact speed.
If pressure is applied, but neither machine looses speed, then even under pressure, both machines will perform the same.
The only advantage you are likely to see is under extreme down pressure, enough to actually cause significant drag on the orbital motion. In this case the stronger machine will maintain more orbital speed, which will will make the pad want to spin more. However at this pressure level it is very likely that the pads have stopped spinning anyways (it takes a lot to bog the orbital motion action of a machine. I know it sounds like they bog (changes in noise) but the actual change is speed is very very little.
Enough theory for one day, I`m exhausted!
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