Random Orbital Diagrams

[kaptain_zero]

Re: Random Orbital Diagrams

I think there may be a few other true DA machines... Makita and Bosch if I recall correctly, but I've not really looked that closely at them so don't hold me to it.

There's nothing wrong with a quality RO though..... Kevin Brown has done an outstanding job at defining just how to make these machines perform. I only hope that one day he will actually RELEASE his paper for all of us to devour.

Regards

Christian

[the_invisible]

Re: Random Orbital Diagrams

The use of the incorrect term "DA" seems to have come about from wanting to distinguish these more capable RO machines from the cheapo RO machines sold at the various *marts and the like.

Great explanation! I think I got what you mean. That seems to explain why my $50 3300rpm Random Orbital has the same dual action movement as, say, the PC!!!

So I guess the only "true" D/A is the Flex, with the forced rotation ability.

[kaptain_zero]

Re: Random Orbital Diagrams

No, there is no differential mechanism, nor is there a clutch mechanism. The shaft that the backing plate attaches to is simply mounted in a bearing and can freewheel, there is no tension on it at all. Try to tighten up or loosen a backing plate on one of these machines (I won't call them dual action as they are not, they are random orbit machines) without using a wrench and you'll find it just turns and turns and turns. If you attempt the same on a dual action machine, and the most notable of those right now is the Flex, you can attach and loosen the backing plate without using a wrench to hold the mounting post still, though it's probably not recommended as that puts a strain on the gear mechanism used to power the circular motion ( but as I don't own one, I'm unaware if a wrench is required to protect the gears when doing this).

There is only the centripetal force that turns the pad while polishing, and that comes from the shaft of the backing plate being mounted off center from the drive shaft. As for a name for this mechanism......... I'm afraid the name is random-orbit. The use of the incorrect term "DA" seems to have come about from wanting to distinguish these more capable RO machines from the cheapo RO machines sold at the various *marts and the like.

I personally don't have a problem with describing the safety aspect as a "clutch like action" to make it simple to understand in a short period of time, but there is NO clutch and so that should be made clear so that people who are new to these machines don't start thinking that because the pad freewheels, the clutch is not working properly, it freewheels because that's what it is supposed to do!

Regards

Christian

[the_invisible]

Re: Random Orbital Diagrams

If the word clutch is a problem, what is the correct name?

Just mechanism?

I don't have the luxury of dissecting my D/A's just to see what kind of thing it is, but in other electrical motor technologies, there is a differential-like system.

If there is no clutch within the D/A, as most people initially thought, then the only thing allowing the the D/A to orbit at a constant rate while allowing it to rotate at a variable speeds is something similar to the differential. Maybe not, but it likely is.

Kind of like the center diff on an AWD car.

[Michael Stoops]

Re: Random Orbital Diagrams

So I'm sitting here with a torn down D/A buffer in front of me - I've got the head of the unit with the shaft sticking out showing the center portion of the electric motor, which I can turn by hand and make the base of the counterweight (the drive housing in your first diagram) rotate in turn. Obviously inside that grease filled head there's a 90 degree turn and the drive housing rotates around that shaft - you can plainly see it. You can also plainly see that the counterweight mounts in an offset fashion, thereby giving the pad this eccentric orbit. Further, when taking a firm hold of the drive housing while still rotating the shaft that goes through the center of the motor, the drive housing will remain stationary.

So, there is a mechanism inside (as Mike Phillips alluded to) that allows some degree of uncoupling to occur - for the primary drive shaft to turn while the drive housing is not. Yet, when we apply similar pressure to a fully assembled machine, the pad will continue to oscillate even though it's no longer rotating. Again, as Mike Phillips mentions, we show this quite visibly when teaching a Saturday detailing class so as to demonstrate this built in safety feature of the G110 (and other makes/models) polisher. Not having removed the cap and cleaned out all the grease - the darn thing is literally packed with red grease - I haven't see the actual mechanism, but I'm assuming you have, Kevin? Can I further assume that you're paper will be addressing this as well?

Obviously you've put a ton of work into this so far and the final result is sure to be an interesting read for all who enjoy this sort of thing. Oh, and a disassembled, painted buffer makes for a pretty cool paperweight!!

[Mike Phillips]

Re: Random Orbital Diagrams

There are no clutches in the random orbital.

Great article Kevin and great diagrams.

And just to note, in the past when I've referred to it as a clutch, (and that would be for hundreds of classes and thousands of people), it's because I needed a term to explain to the average person sitting in a classroom, sometimes 20 people sometimes 50 people that they can wrap their minds around.

There was about 45 people in the Tampa Roadshow Class back in April of 2006






Dissecting a topic on a discussion forum is alway a fun sport, standing in front of large groups of people explaining the safety features of a tool when most of the people are scared they're going to either instill swirls or burn through the paint are two different things and often times I'm simply trying to address a BIGGER pictures than a handful of people on some discussion forum.

Make sense?



For example, the class I taught just this last weekend for Porsche owners; most the guys attending this could wrap their minds around the idea of a mechanism that has the ability to slip so as not to instill swirls and/or remove too much paint and burn through the clear and expose the color coat.

Including the owner, who had never used a machine on paint before this class and now has the confidence to use one to finish creating a swirl-free finish over the rest of his Porsche.

By the way, has anyone figured out what the SPECIFIC name is for the "Mechanisms" used in the 3 varieties of DA Polishers?

• PC
• G110/G220
• Griot's ROP

If the word clutch is a problem, what is the correct name?

Just mechanism?

[SHYNEMAN123]

Re: Random Orbital Diagrams

No question, Dynabrade is a great brand. Good tools. And this one is a good tool. I'm saying it may not be the best for defect removal.

Couplers and fittings used with this tool have been variable. I travel frequently and I test tools/products all over the world. So I'm sure there has been no consistency in couplers used. But here's what I'm going to do...
- I believe our training center uses those. I will try the tool there.
- I know the chief engineer at Dynabrade, I will discuss it with him and get his opinion on the matter.

If I have a new experience with the tool, I will get back to you. Thanks for the question.

I really appreciate it.

[Jason Rose]

Re: Random Orbital Diagrams

Thanks Jason
I thought it might be to good to be true but with it being Dynabrade I have never been disappointed in anything I have bought with there name on it.

I have very clear understanding of the torque loss with pneumatic tools.
Do you run high flow couplers ?

No question, Dynabrade is a great brand. Good tools. And this one is a good tool. I'm saying it may not be the best for defect removal.

Couplers and fittings used with this tool have been variable. I travel frequently and I test tools/products all over the world. So I'm sure there has been no consistency in couplers used. But here's what I'm going to do...
- I believe our training center uses those. I will try the tool there.
- I know the chief engineer at Dynabrade, I will discuss it with him and get his opinion on the matter.

If I have a new experience with the tool, I will get back to you. Thanks for the question.

[SHYNEMAN123]

Re: Random Orbital Diagrams

I have one. Used it many times. But it's not the panacea it might seem.
- She gots power, until you put some downward force on the tool, and then she stops (somewhat depends on what air compressor you have driving it. But even the strongest one I have available to me...still stopped the pad rotation with some downward pressure.) The tool was made primarily for sanding (where you don't want pad spin too much.)
- The "rotary" setting. Is not true rotary. Still slightly offset. And again, she stops rotating with some downward pressure.

The tool makes a good polishing and waxing tool, but not the best for defect removal.

That's my 2 cents.

Thanks Jason
I thought it might be to good to be true but with it being Dynabrade I have never been disappointed in anything I have bought with there name on it.

I have very clear understanding of the torque loss with pneumatic tools.
Do you run high flow couplers ?

I just got off the phone with Dynabrade and the Dynalocke in the rotary mode was designed for light sanding on just the out side edge of the disc.They do make a true rotary in the same housing but with a price tag of $523.00 m/n 10745 ouch.

[Jason Rose]

Re: Random Orbital Diagrams

Kevin,
Well done. I also want to say thanks for your enthusiasm and effort. You have a lot to offer the detailing world. Thanks for putting yourself out there.

I know we've discussed it many times, but your diagrams make it so real for me now...

The commonly accepted name for tools like this is a "Dual Action Random Orbital" tool. Which, based on your drawings, is not very accurate. If I could go back in history and rename this tool, I would call it a "Dual Action Random Rotational" tool. (Or something like that, but shorter.)

The orbital part of the action is actually fixed, not random. The rotational part, and pad rotation speed, is really the random part of the dual action.

But I guess you can't change it now. The detailing arena, and several other industries, know this tool by a certain name...however inaccurate it might be.

[Jason Rose]

Re: Random Orbital Diagrams

No but it should REALLY rock! If I were a salesman, my pitch might be:

"She got a 3/16" stroke.

She dual mode- Lemme tell YOU! - really knocks 'er down in a hurry.

She got .4 horse.
A lot more than most her size, heck- more than most that'r twice as bigazz-er!

She'll do 12,000 RPM.

Now- how many do you NEED?!"

I have one. Used it many times. But it's not the panacea it might seem.
- She gots power, until you put some downward force on the tool, and then she stops (somewhat depends on what air compressor you have driving it. But even the strongest one I have available to me...still stopped the pad rotation with some downward pressure.) The tool was made primarily for sanding (where you don't want pad spin too much.)
- The "rotary" setting. Is not true rotary. Still slightly offset. And again, she stops rotating with some downward pressure.

The tool makes a good polishing and waxing tool, but not the best for defect removal.

That's my 2 cents.

[Zeta Detail]

Re: Random Orbital Diagrams

what an impressive job, Kevin. You sure can use editing and publishing software. If this is how the finished "Kevin Brown Paper" is going to look like all I can say is I CAN'T WAIT TO READ IT!!!

Thanks for your time in designing those instructional diagrams

[Kevin Brown]

Re: Random Orbital Diagrams

Great writeup and use of diagrams. The only way to break it down any simpler would have included the use of sock puppets!

Ahhh, yes! Sock puppets! Shucks- all the GOOD ideas are already taken.

But still the way you simplified a very complex operation took a lot of time and effort on your part and I thank you for your passion and teaching...

Ohhhhh!
I was so far out their in left field, I thought you were trying to say in a nice way, "UH-uh. No-go. Not gonna do it. Try again."
Well... thanks!

[SHYNEMAN123]

Re: Random Orbital Diagrams

OH!

Well- I didn't modify the diagrams a thousand times but it sure FELT like it!

Maybe if I added up all the changes AFTER I thought I was done...

But still the way you simplified a very complex operation took a lot of time and effort on your part and I thank you for your passion and teaching. That is why I love this forum.

[Kevin Brown]

Re: Random Orbital Diagrams

The Dyson vacuum cleaner that the inventor had over 1000 failures B4
it worked. No filter No clogging.

OH!

Well- I didn't modify the diagrams a thousand times but it sure FELT like it!

Maybe if I added up all the changes AFTER I thought I was done...