Griot's Polisher First Impression

Mosca said:
Interesting, thinking it through you'd think that there should be almost no difference. Aggressiveness should be as much a function of pad and product as it is of oscillation; a smaller oscillation should be offset by a higher frequency of oscillation.



If the oscillation is smaller with a similar frequency, then the difference in work produced should be linear. At the same speed, a 50% difference in size of orbit should mean that a job would take twice as long. But at twice the speed, it should take the same time. The job is moving product over surface over time, nothing more.



What is the frequency of oscillation of the PC at speeds 1-6?





Tom
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The PC maxes out at 6,000 OPM, which correlates to "6" on the dial, though I don't believe the rest correlate at 'X' * 1000 as the step between 5 and 6 seems significant.



The Griot's tool only runs up to 7,000 OPM, right? So that's not a very big increase.



Also, I'd question the linear progression as that falls apart at extremes, like as you approach no offset. And as you approach larger offsets the action would become more like a rotary as the random spin of the pad can't compensate for the forced movement of the offset in terms of keeping one spot of the pad stationary while the rest moves around it (which is why the PC doesn't tear into things when it catches on them), thus making it a fair bit more aggressive, and I'd imagine more dangerous. I think it definitely doesn't scale linearly with working time. Using the safe PC for 2-3 times as long in a spot wouldn't be as dangerous as a PC with 3-times the throw used in a spot (like holding it in a spot for 15 seconds vs the PC in one spot for 45 seconds).



It's just opinion, but I'd think in general the offset would have more of an effect than the speed would and definitely more than the time-used would. I bet a PC with twice the throw, running at 3000 OPM would be more aggressive than the PC cranked up to 6000 OPM. Maybe not, though, just an opinion. :)



I also think throw compared to the diameter of the pad is what's important, not so much total throw. This, IMO, is why the Cyclo is more aggressive/capable, plus it's stronger motor.



But if you think about what makes the DA "safe", it's that the pad can basically stay in one spot on one part of the pad. The more throw compared to diameter of the pad, the less this is true and the more the pad has to move to some degree over any spot.
 
velobard said:
OK then, I was just going by what I interpreted other folks as saying in another thread awhile back. As I recall, they said the difference between a DA (the PC) and a RO was that the PC had a forced rotation. I don't have one yet, just my old Bosch RO. The bit about the longer RO action should still have an effect though. I can't recall the #'s for sure, but it seems like someone said the PC had something like 8-10 mm orbits and a typical RO was more like 5-6 mm.
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Yeah,people have posted those specs but I dunno where they got them.



There *is* a sorta hybrid polisher with forced rotation...the BO6040 or something like that. Seems like most people who've tried it don't like it.



IMO the big difference between the PC and a "RO" is just one of conventional semantics. The PC *is* a "random orbital sander", says so right on the box and in the product literature. We've just come to use the term RO to generally refer to the bigger, less powerful units like the WaxMaster (or whatever it's called).



Before the PC got so popular, people were using numerous other 5-6" Random Orbital sanders with similar results. E.g., Griot's first sold a 5" Metabo, then the PC (first in 5" then 6"), and now they sell this one...
 
Does wearing something like Mechanix gloves with the supposed vibration absorbing pads on them help when working with the PC? I have personally never used mine so long that it made my hands numb, or caused any discomfort at all.



This thread is perplexing. The guy over on Meguiar's board says he was around 240 lbs. and he leaned on the Griot's polisher without it bogging down. Yet someone on here says it bogged easier than the PC. Strange.
 
Mosca said:
I'm not familiar with the tool; is it electric or pneumatic? And I'd assume that it is UP TO 10000 rpm? Wouldn't one speed be harder to adapt to different jobs?



Sounds interesting.



My problem with the PC's comfort isn't until I go to bed and my hands fall asleep and start hurting.





Tom
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Yes the speed is adjustable- I kinda visualize the smaller pattern RO as a less aggressive rotary although I haven't really had a chance to use mine(BigLots RO) on anyting other than a tractor hood.
 
Accumulator said:
Caraman- Are you saying that the Griot's cuts *better/faster/etc.* compared to the PC? That would make it one vote for one, one for the other, which would at least make this discussion more intriguing :D Your description of it is similar to what some of us have said about the Cyclo.
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From what I've seen thus far, Griot's machine does cut better/faster than the PC. A very worthwhile investment as far as I'm concerned! :waxing:
 
Accumulator said:
Yeah,people have posted those specs but I dunno where they got them.



There *is* a sorta hybrid polisher with forced rotation...the BO6040 or something like that. Seems like most people who've tried it don't like it.



IMO the big difference between the PC and a "RO" is just one of conventional semantics. The PC *is* a "random orbital sander", says so right on the box and in the product literature. We've just come to use the term RO to generally refer to the bigger, less powerful units like the WaxMaster (or whatever it's called).



Before the PC got so popular, people were using numerous other 5-6" Random Orbital sanders with similar results. E.g., Griot's first sold a 5" Metabo, then the PC (first in 5" then 6"), and now they sell this one...
Click to expand...





The PC is a DA, which is a little different from a standard RO. I think when the earlier poster was talking about forced rotation he was just confused. A RO osciliates around it's center. Think of a circle, a RO osciliates within the circle, from the center. A DA, however, osciilates off of an orbit. Using the circle example again, a DA osicliates along the path of the diameter of the circle, with it's center constanyl changing as it moves along it's "orbit".



It's hard to explain, so I hiope you understand. Of course, the PC is not the only DA. And if the Griots is simply a RO and not DA, I can see why it not only cibrates less, but also why it may correct less.
 
DA = RO.



Forced rotation = dual action/random orbit pattern (xxxx-yyyy OPM), + slow, direct drive rotation like a rotary; @ the 290-670 RPM range; type dependent (slowest value Bosch, quickest Makita). Typical examples: Makita BO6040, Festool Rotex RO150E, Bosch GEX150 Turbo (1250 DEVS in the States), Kress MPS900, etc.



Frequency: OPM×2. One orbit, aka a small ellipse; forth/back (according to Bosch).
 
Aurora40 said:
Also, I'd question the linear progression as that falls apart at extremes, like as you approach no offset. And as you approach larger offsets the action would become more like a rotary as the random spin of the pad can't compensate for the forced movement of the offset in terms of keeping one spot of the pad stationary while the rest moves around it (which is why the PC doesn't tear into things when it catches on them), thus making it a fair bit more aggressive, and I'd imagine more dangerous. I think it definitely doesn't scale linearly with working time. Using the safe PC for 2-3 times as long in a spot wouldn't be as dangerous as a PC with 3-times the throw used in a spot (like holding it in a spot for 15 seconds vs the PC in one spot for 45 seconds).



It's just opinion, but I'd think in general the offset would have more of an effect than the speed would and definitely more than the time-used would. I bet a PC with twice the throw, running at 3000 OPM would be more aggressive than the PC cranked up to 6000 OPM. Maybe not, though, just an opinion. :)



I also think throw compared to the diameter of the pad is what's important, not so much total throw. This, IMO, is why the Cyclo is more aggressive/capable, plus it's stronger motor.



But if you think about what makes the DA "safe", it's that the pad can basically stay in one spot on one part of the pad. The more throw compared to diameter of the pad, the less this is true and the more the pad has to move to some degree over any spot.
Click to expand...





Hmmmm. I'm not sure I understand what you're saying.



Let me think a moment. A PC with 3x the throw, but the same frequency. Would it do more than 3x the work?



You might be on to something; the relationship is probably not linear, it's probably logarithmic or squared or something like that.





Tom
 
Mosca said:
Hmmmm. I'm not sure I understand what you're saying.



Let me think a moment. A PC with 3x the throw, but the same frequency. Would it do more than 3x the work?



You might be on to something; the relationship is probably not linear, it's probably logarithmic or squared or something like that.





Tom
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Well, I don't know if it would do more than 3x the work. But here's what I think. If you ran the PC at the normal throw at 9,000 OPM, it would probably do less work, create less heat, etc, than if you had a PC with 3x the throw running at 3,000 OPM.



Take this example, you have a 4" pad and a 2" offset. Since the pad can spin about it's access, the tool is still "random" in the sense that you can't predict where any part of the pad will go, but it doesn't mean the pad can go anywhere. You'll basically have the effect of an 8" rotary pad, except with about 1/4 the actual contact area. Imagine that running at 3000 OPM/RPM compared to a PC with a 2/3" offset running at 9000 OPM (which would be kind of like half a Cyclo but moving a lot faster). Granted both would suck to try to use or keep flat, but I think the 2" throw could probably quite easily blister paint, whereas the other probably would not.
 
gbackus said:
The PC is a DA, which is a little different from a standard RO...[explanation follows].. It's hard to explain, so I hiope you understand. Of course, the PC is not the only DA...
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I follow your description but I think the difference is between different types of random orbital devices. Heh heh, hope we're not navel-gazing or otherwise just arguing semantics (always a losing game for everyone involved).



I follow your explantion, but I think you're describing different types of random orbital devices. I see that as an umbrella term (perhaps a family as opposed to a genus or an order).



I used air powered DAs in a body shop back in the day, and while the motions were slightly different, the general effect always seemed the same as that of the PC. So yeah, I always thought of the PC as a Dual-Action device, ditto for the Cyclo. But as I said, the PC is described by the *manufacturer* as being a random orbital sander, says so on the box and in the product literature (which explains how it works). It was my understanding that the random orbital action is accomplished via the two motions, i.e., the dual-action (the "dual" part being oscillation and rotation).



That's not to say that there aren't different types of random orbital devices, and I've never used the ones to which the the term is commonly applied these days. I imagine they are different in some ways (this differentiation would be at the genus level), but not in the sense that they're so different as to negate what PC has been calling their tool for decades. Heh heh, other than the way we're using a few words, I think you and I are in agreement on this thread's topic anyhow so it's silly for us to :argue Sorry if I've beaten the subject to death with my take on it :o



Caraman- OK. That makes one person who says "more effective" and another who says "less". We'll see what the next person says. I find this sort of comparative difference interesting.



Mosca & Aurora40- I'm finding your discussion interesting too :D
 
I tend to visualize that a longer throw moves the pad across the paint(distance wise) possibly inducing micromarring with more aggressive products vs a smaller tighter orbit at a higher speed
 
You say something because my Bosch has a modest 4 mm pad throw, but oscillates up to 24.000/min and it finishes down even the liquid sandpapers to near LSP-ready or LSP-ready levels (even on CDs).
 
Wouldn't a greater throw result in less work being applied to a given (concentrated/center-of-focus) area over the same period of time? Or in other words, wouldn't a shorter throw result in more work being applied to the given area?



It occurs to me that with a shorter throw you're getting closer to the behavior of a rotary and the vision of a rotary with an off-center pad comes to mind...wouldn't that be similar to a DA without the rotation half of the "dual", like a pure high-speed oscillation?
 
Well, if you had no throw, the machine would do nothing. The reason is that the pad itself is free to spin on its axis. The friction is from moving the entire pad around, not rotating it. So the longer the throw (to a point) the more it is moving the entire pad around.
 
OK, I failed to keep it all DA-specific inthat the DAs always allow the free-spinning rotation (except for the forced-rotation one). I knew I wasn't thinking of something, should've had more coffee before posting :o
 
I got a Griots RO for Valentines Day (she got Diamonds..), but anyway. i was reading about some comments how the Griots doesnt cut as good as the PC or others. and i just wanted to tell everyone what came in some of the Books from Griots.

They have 3 different Machine Polishes for the RO, from uber-fine to medium and one Polish pad. They say that the RO is a good begginer orbiter because it doesnt cut as much. The Griots book says that if you have real bad swirls then a direct orbiter is your best bet. which makes sense, but im not skilled enough to go using a direct drive and my cars not that old.

Havent used it yet, but if you guys wanna know my thoughts after the 3ft of snow melts, just let me know.
 
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