PC speed vs. Buffer Speed ?????

[Open Air]

How does the OPM of 2,500-6,000 on the PC 7424 (G-100) compare to speeds associated with a Rotary speed of 1,800 RPM as referenced in Mike's post on the 1999 Vette using #83?

(By the way this is a must see extreme makeover - AWESOME).

It seems to me that the PC spins faster even at its lowest setting compared to a rotary buffer. I've learned that heat is one of the reasons why rotaries (in the hands of trained professionals) can achieve much better results on defects than the PC, but I thought that it would be the speed of the machine that creates that heat, hence softening the paint or clear.

Is there less heat build-up with the PC because of its osillating action or is something else going on here?

Thanks.

[rusty bumper]

Re: PC speed vs. Buffer Speed ?????

Originally posted by Open Air
How does the OPM of 2,500-6,000 on the PC 7424 (G-100) compare to speeds associated with a Rotary speed of 1,800 RPM as referenced in Mike's post on the 1999 Vette using #83?

(By the way this is a must see extreme makeover - AWESOME).

It seems to me that the PC spins faster even at its lowest setting compared to a rotary buffer. I've learned that heat is one of the reasons why rotaries (in the hands of trained professionals) can achieve much better results on defects than the PC, but I thought that it would be the speed of the machine that creates that heat, hence softening the paint or clear.

Is there less heat build-up with the PC because of its osillating action or is something else going on here?

Thanks.

Rotary buffers use torque to build up heat...You can bear down on a rotary and the pad will continue to spin.

On the other hand, a PC pad will stop spinning if you apply much pressure to it. If you hold a PC in your hand (Switch in off position), you can spin the pad freely...If you do the same to a rotary, you will feel resistance due to the way it is geared.

Another good way to explain it is, a rotary is a direct drive machine, (It is geared from the motor to the pad spindle)....But a PC is not directly geared to the spindle. It is geared to the part that holds the balance weights...The spindle does orbit under torque, but spindle itself has no direct torque to make it spin.

I hope I explained this well enough...

[Open Air]

R.B.

Thanks!

That is very interesting and useful information.

Yeh, when I look at the PC it appears the spindle is attached to a free-floating sealed bearing assembly similar to what you might see on a skate board wheel (Spins freely with almost no effort).

I guess what your saying is that the only forces that cause the pad to spin is the circular/oscilating motion of the counterweight. When too much pressure is applied, friction from the pad will override the centrifical forces acting on the spindle and the pad will stop spinning.

Where as with the rotary buffer the spindle is directly and mechanically connected to the motor. And as such greater pressures can be utilized without significantly effecting the speed of the pad.

Correct?

[rusty bumper]

That's another good way to explain it.

A rotary buffer works a lot like a metal grinder, or a power sander, or a floor polisher...These machines may be different from one another but the principle is the same.

I'd like to have a rotary sometime in the near future...