How fast does a DA really go? Confused.

[waxyboard]

I have a really dumb noob question.

I am watching videos of the dual action polishing machines, I bought a Griots one for $110 on Amazon.

Watching some videos online I can hear the motor seemingly rev up to high RPMS but it looks like it is rotating super slow, and in the manual that comes with this unit, it says something about using a speed of 1-2 revolutions per second.

But when I turned the thing on, it is ridiculously fast. I only blipped it on for a second on a lower setting. This is an extremely high speed machine.

So are these things going extremely fast but it just looks slow on the youtube videos because of the video camera capture rate? Or does this thing go into some super slow motion mode when you apply pressure??

thank you!

[Detailing by M]

Uh it has q clutch so it slows down the more you push on it.
It's not like a rotary or flex.

[waxyboard]

Re: How fast does a DA really go? Confused.

How slow? How many revolutions per second? Thanks for responding. Am I suppose to push down hard on this so it slows down? Or can I just let the weight of the machine mostly do the work?

Oh and this is
Griot's Garage 10765LNGCRD 6-Inch Random Orbital Polisher

[davey g-force]

Re: How fast does a DA really go? Confused.

If you're doing paint correction, you would generally push down just hard enough so that the pad is rotating quite slowly. Don't let it stop, or you won't get much correction done!

[davey g-force]

Re: How fast does a DA really go? Confused.

Mark a line on the backing plate with a marker pen to help you see how fast the pad is rotating.

[waxyboard]

Re: How fast does a DA really go? Confused.

Thanks. I think the problem being a total utter noob, is that it feels like the pad is spinning at an insane rate from the sound and viberations, but in actuality, it is very gentle. I guess all that energy is put into the circular orbit motion rather than spinning the pad very fast. I put a mark on the pad and stuck it on a paper towel and it did nothing to it. Wow, this is amazing. OK, sorry for the stupid question. I'm just starting out with doing this stuff myself, it has always been an interest of mine but just seemed too intimidating till I started doing some research.

[Top Gear]

Re: How fast does a DA really go? Confused.

Right, it's oscillating eccentrically more than spinning like a drill - the two actions in "dual action". If you hold it in open air it will spin up fast to the RPM setting (spraying product all over the place if wet), but even on a high setting it's not actually spinning very fast in use on the paint. It's really ingenious, the best thing since sliced bread

[Michael Stoops]

Re: How fast does a DA really go? Confused.

What you're seeing is the difference between "no load" and "load" speeds. If you turn the tool on at, say, speed setting 5 or 6 with a pad stuck to it, but you just hold it up in the air, there is the very real chance that the pad will fly off. This is because with no load the entire assembly is free to spin at max speed and, since it oscillates the pad rather than just spinning it in a perfect circle like a rotary does, it can fling the pad off.

A rotary buffer is a direct drive, high torque tool that spins the pad in a perfect circle and won't slow down even if you apply a lot of pressure to the paint. In fact, the paint will give up long before the buffer will. With a DA buffer the pad still spins, but the offset aspect and the free rotating spindle (there isn't actually a true clutch mechanism) are the big safety factors. Put some load to the tool (ie, place the pad against the paint and add some pressure to it) and the rotation will slow as that free rotating spindle has to essentially overcome the pressure. The oscillation will continue virtually unabated, but the rotation will slow and can even be stopped completely. Heavy pressure will stop rotation, as will tipping the pad to one side, but the oscillation will continue. In order to get any serious defect correction with a DA you need the right mix of pressure, oscillation and rotation. In most cases that means you'll be using speed 5, moderate pressure, and you must keep the pad as flat to the paint as possible to maintain rotation. Slow rotation is perfectly fine and indicates that you've got sufficient pressure to actually get some work done. If you just use the weight of the tool (ie, very light pressure) at speed 5 odds are you'll have frustratingly slow defect removal, if not complete failure. Of course, this is a big part of the reason why we always stress that you do a test spot the first time you work on any car.

But trying to evaluate a DA buffer by just switching it on under "no load" conditions doesn't really tell you much of anything about the tool. In fact, on our own G110v2 we've heard people complain about a sometime speed surge at speed setting 1 under no load conditions. They are convinced that the tool is defective, when in fact it's the Cruise Control circuitry being confused by the no load and slow speed. Speed 1 is almost never used for any process - rarely do you go below 3 even when applying wax - but at higher speeds that same Cruise Control circuitry will help to maintain rotation even with a fair amount of pressure applied.

As to the actual speeds of your Griot's DA, they list the speed range as being 2,500 to 6,800 orbits per minute (opm). Our G11v2 ranges from 1,800 to 6,800 opm. That might sound high when compared to rotary buffers that usually range from 600 to 3,000 revolutions per minute (rpm) but the measurements don't directly correlate like, say, centimeters and inches do. That's because of the direct drive versus free rotating spindle, circular spin versus oscillation, etc.