The Rupes BIGFOOT LHR 21E is heading to the USA!!!

[Legacy]

Hi Kevin,



Does this machine have a forced rotation assembly similar to that of the Flex 3401 or does it use a free rotating spindle assembly making it like a PC style DA on steroids? I have looked through the technical drawings and it appears that there a sort of housing that possibly has a ring gear inside of it similar to the Flex offering, but looking at the parts breakdown or exploded view, it also appears that there could be a free rotating spindle assembly.



Bottom line is that I`m simply not interested in a machine that works just like a Flex 3401 made by a different manufacturer as I already own 2 Flex 3401 units. However, if there is a high quality machine sporting a free rotating spindle assembly with a larger orbit and faster cutting action than that of the PC style machines, I`ll be on board for something like that for sure.



I know you`re a busy man especially with SEMA coming up soon, and I`m in no hurry to buy a new toy. Please at your convenience if you would, shed some light on how this machine works compared to the PC or the Flex 3401 here in this thread or direct me to the literature that will explain the difference/similarities.



Thanks in advance, TD

The ad said rpm...should it be opm`s?

[BigAl3]

Kevin Brown- IIRC you`ve touched on this in another thread (apologies if I`m asking for a rehash), but could you please present an argument for buying the Rupes LHR 21E Bigfoot instead of the new version of the Griot`s Garage 6" RO?

the motor is still the same as the previous version, the only difference now is the ergonomics as well as the rubber on top of the polisher & bale handle...

[gmblack3]

Rupes cuts faster then my dynabrade setup. Db cuts 2x faster then my Gg.

[David Fermani]

Rupes cuts faster then my dynabrade setup. Db cuts 2x faster then my Gg.

I`ll have to say a prayer tonight that my 3 DA`s die so I`ll be forced to buy one! :pray2: This sucker looks impressive.



Kevin - are you going to have one @ SEMA for me to play with? :waxing:

[drew935]

You do that David, lol.



I am praying that the Rupes will get here in 2 weeks. :angel:

[Garry Dean]

I hope someone will have one at SEMA... Im anxious to get one of these bad boys!

[Accumulator]

C. Charles Hahn & gmblack3- Hey, thanks for the info on how the Rupes` 21mm stroke lets it cut better than the GG 6". Ah yes...I`m now vaguely remembering Kevin`s other posts about that.



Any downside to it? I`m thinking about, say....finishing; my Cyclos finish out a bit better than my GG does, though it might be some user-related factor I haven`t considered.

[RaskyR1]

C. Charles Hahn & gmblack3- Hey, thanks for the info on how the Rupes` 21mm stroke lets it cut better than the GG 6". Ah yes...I`m now vaguely remembering Kevin`s other posts about that.



Any downside to it? I`m thinking about, say....finishing; my Cyclos finish out a bit better than my GG does, though it might be some user-related factor I haven`t considered.

They finished down very well at the NXTi class...and that was using MF pads and D300!!!



Only downside I could see was tight areas, but I have other tools for tacking those as I already do now.

[C. Charles Hahn]

C. Charles Hahn & gmblack3- Hey, thanks for the info on how the Rupes` 21mm stroke lets it cut better than the GG 6". Ah yes...I`m now vaguely remembering Kevin`s other posts about that.



Any downside to it? I`m thinking about, say....finishing; my Cyclos finish out a bit better than my GG does, though it might be some user-related factor I haven`t considered.

Well, Rupes makes both a 21mm and 15mm stroke version of the machine; I would imagine the 21mm is mainly intended to be used for the cutting/compounding stage, and the 15mm (or other smaller stroke machine) for better finishing.

[Accumulator]

RaskyR1- Ah, thanks for the "finishing down" observation.



Eh, I`d better get off this thread before I start thinking about yet another polisher!

[Kevin Brown]

Dave- the Rupes LHR 21E is a random orbital. It does not use any sort of mechanical or forced or driven rotation.



Charlie- In general and for the most part, a large stroke machine will cut faster AND finish better than a short stroke machine.



Certainly a short stroke machine could be made to deliver a similar cut and finish result, but barring modifications to the machine (which might clean the pad as it worked, or exchanged the compound via a slurry & pump system), most of the advances would come via methodology changes. Diligent cleaning of the pad and compound could be the equalizer; However, the time spent to keep the working area clean would certainly be some sort of commitment.



This is a large topic to cover, which is why I wrote this article quite some time ago (way before any of us even heard of a Rupes BigFoot):



Machine Stroke - How it Affects Sanding and Polishing Performance



I could write a massive post about large stroke machines, but most of it is covered in the above listed article. Here are the benefits I could think of right now, as I write, without listing the reasoning (feel free to read the article or call me for the info, if needed).



All other things being equal (machine, backing plate, buffing pad and liquid)... a large stroke machine will:



• Create more centripetal force. What does this mean in the real world?

The backing plate will spin more rapidly (and it will be more difficult to slow the rotational speed because large stroke machines usually have heavier rotating assemblies)



• Power through resistances more easily (such as paint, surface oxidation & contaminants, uneven or scratched surfaces, panel contours, drag caused by abrasive compounds, etc.)



• Keep pads cleaner (particularly foam pads), as they do not have an ability to become tied or knotted or clumped together the way fibrous pads might (wool, microfinger, microfiber, felt, etc.)



• Deliver a smoother polishing pattern, especially at the curlicue transition point



• Keep compounds and polishes moving at a more rapid pace per revolution



• Essentially do more "work" per revolution, which means that machine speed can either be lowered to achieve the same result (thus potentially increasing user comfort), or more work can be accomplished in the same period of time, or the pad can be used longer before it "loads up" and requires cleaning



• Allow you to use a larger diameter pad and achieve similar or better performance than you might see when using a smaller diameter pad on a typical 8mm diameter stroke random orbital ("performance"= cutting speed, finishing ability, user comfort, etc.)





Use a short stroke machine:



• When you are working on items that may be fragile, such as delicate or thin or old objects



• When you wish to confine sanding or polishing to a very specific area



• When you are working in tight spaces or on small parts



• If the item you are working on benefits from a minimum amount of backing plate rotation

[JohnKleven]

Looks like a great machine Kevin. Will you be at SEMA this year? I`d love to try it out.

[Kevin Brown]

I will be there. If my shipment arrives in time, I will bring one with me.

[imported_WhyteWizard]

From the Rupes website about the Bigfoot: "The antispinning feature prevents the high speed rotations avoiding scratches"



What does this mean in practice? Does the pad spin or not? Is the spin kept down or eliminated completely?



Robert

[imported_ZimRandy]

I will be there. If my shipment arrives in time, I will bring one with me.

Please post up where you`ll be with the Rupes if you get them. I`d love to check it out at SEMA.



Randy