My PC doesnt spin a whole lot

Bowens99gt

New member
I've always wondered why it doesnt spin as fast as I think it should. Like if theres a mark on the backing plate or something I can see it go around but it sure isnt as fast as I think it should be. The whole thing shakes and what not. It seems like a regular buffer that vibrates. I got the one from lowe's. Do I need a different counterweight? Or is this normal?



thanks



Brandon
 
That's pretty much normal with a PC. If you don't apply as much pressure you'll notice that it rotates a bit more, apply too much pressure and all it will do is sort of "jiggle". Larger pads (like 7.5")will also bog the PC down more than 6/6.5" pads.



The motion of the PC (OPM's) rather than straight RPM's like a rotary is also the reason it is so safe for paint. The higher speeds of the rotary make it much easier to burn through paint if you aren't careful.
 
I too am really confused by this. I hardly need any pressure for it to stop spinning. In fact it stops spinning under its own weight. What's the point of the spinning if it stops this easily? Or is my PC broken?
 
At higher RPMs I've found that it looks like it isn't spinning, but that it's just an optical illusion. Of course, with pressure it does become bogged down and stop spinning at well.
 
Try placing pressure on the head of the machine and remove the handle. If at any time the weight becomes unbalanced it will "jiggle." It takes practice, but applying equal pressure to the PC while keeping it balanced will still allow it to spin at higher speeds with pressure. I used a grease pencil to mark the BP when I first got my PC. It took a little while to perfect the technique, but it is just muscle memory now. Give it a try.
 
Like the others stated, a PC does not really "spin", it oscillates. It is an eliptical motion. If it was a rotary and did not spin, you would definitely need to be concerned. My mini Wen orbital also appears as if it is not "spinning".
 
It' supposed to both spin/rotate *and* oscillate; that's the "dual action" motion. Yeah, the PC bogs down very easily and then it just "jiggles" (oscillates). That's a downside to polishing paint with something that was designed for use as a finish sander on wood (where you do *not* apply pressure; you let the sandpaper do the work).



Using a 4" pad will help immensely.



If you want a D/A polisher that won't bog down, get a Cyclo ;)
 
Accumulator said:
It' supposed to both spin/rotate *and* oscillate; that's the "dual action" motion. Yeah, the PC bogs down very easily and then it just "jiggles" (oscillates). That's a downside to polishing paint with something that was designed for use as a finish sander on wood (where you do *not* apply pressure; you let the sandpaper do the work).



Using a 4" pad will help immensely.



If you want a D/A polisher that won't bog down, get a Cyclo ;)



Accumulator, if I use 4" pads on my (locally made) polisher, do I need a different backing plate, or is it ok with the 5 1/2" plate already on it? Thanks.
 
sorry if this sounds dumb but why would autopia sell these with the 6" pads and not 4", if the larger pads stop the PC from spinning like it is supposed to?
 
sorry if this sounds dumb but why would autopia sell these with the 6" pads and not 4", if the larger pads stop the PC from spinning like it is supposed to?



By these do you mean the PC?



6 1/2" pads certainly can remove defects, infact people have gone through clear and into the primer to illistrate a point.



The harder pads such as my orange DAS pad spins like crazy even on 5. On 6 it is a beast.



The softer pads require perfect centered pressure to get a rotation.



Truth is, if one is using one of the softer pads, then a jiggle may be all is needed anyhow.



The 4" spot pads require alittle more attention to prevent a problem from occuring. Not anywhere near as much as a rotary, but the little pads will heat up, burn paint on rubber bumpers, or rub a hole through the clear coat(with multiple attempts at removing a scratch that should be left alone), unless you know what you are doing.



That doesnt mean an MIT degree either, just common sense, and an idea of the products capabilities.
 
Not trying to bust you or anything but, you do know that it is adjustable? The speed that is, and it's not like a rotary.



Good luck,

Sellncars
 
Accumulator said:
Yeah, use the smaller plate.



Actually, I realize the smaller plate would be better, but my machine is NOT a PC, and I can't change the plate. Besides the fact that the edge of the plate will protrude, do you think the slightly larger plate would be "usable"?
 
Any protrusion beyond the edge of the pad would be enough to nix the idea for me.



If the plate *does* protrude, you could probably cut it down somehow but that would make for problems with the "regular" size pads. So get a second plate and cut on *it*.
 
I made a video demo of using the PC for some guys on another forum I visit. They were saying how the PC is just as bad or worse than a rotary at damaging the paint. To prove them wrong I held the PC at speed 6 in one spot on my fender for an extended period and proved there is NO damage from it. I was working in some DACP at the time.



This shows a good technique (after the holding it in one spot part) and also in some parts you can see the way a PC is supposed to operate when it's fully functioning as it should.



http://www.hahn-on-the.net/TBECentral/pcdemo.wmv



Just be warned it's an 8.1 MB file. You probably will want to do a 'Right Click, Save As' to speed up your download.
 
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