Rupes 21 -vs- Rupes 21 Mark II

[axel06]

Mark II = the beast

[RaskyR1]

The Mark II tools feature some external differences:
1) rubber rest on the top of the tool
2) completely redesigned forward grip that is now solid and one piece - it is more comfortable and more rugged
3) a RPM diagram relative to speed dial setting
4) a more powerful (torque) motor and upgraded electronic controls that maintain RPM under load which directly increase the forces that control rotation

Here is answer I typed on Autopia to a similar question. I hope it helps.

Good to see these improvements were made! While I loved my original LHR15 and LHR21, these were some things that frustrated me a little.

[Dylan@RUPES]

Good to see these improvements were made! While I loved my original LHR15 and LHR21, these were some things that frustrated me a little.

Heard this comment and similar quite a bit at SEMA. Very few people disliked the Bigfoot as it was, but with anything there is always small changes that can be made to improve the user experience or performance. I like to say that the Mark II release is EVOLUTIONARY not REVOLUTIONARY. We simply made a great thing better... and the changes are all in direct response to end user feedback. We listen and respond. Something I don't think any other company in our segment of the industry does to the degree we do

[225]

When will the Mark 2 be available?

[Dylan@RUPES]

Mid December, they are already in production.

[LimitlessDetail]

Mid December, they are already in production.

Is that both 110v+240v versions being made? Only asking for the guys in australia who are keen as (There is about 30 detailers so far who are very keen on the new stuff from Rupes)

[cardaddy]

Wow!

I truly feel guilty for not being able to respond to this (nor read all of it) at this time.

The only analogy I can think of is most paint experts still tell you to wait 30-90 days to wax a car. However, if you speak to the actual chemists they will tell you that the paints they formulate are safe to wax hours to days after. The change in chemical formulation of modern catalyzed clear coats has represented a paradigm shift, yet many experts are slow to catch up. Waiting 30 to 90 days is still recommended (usually) and nothing bad will come of it.

If you go back far enough, you can find quotes where I have said that rotary polishers are the only way to correct paint (7+ years ago). Technology moves forward and sometimes to stay on top of requires changing are view points about certain things. I have been fortunate enough to work with some of the leaders in this industry and my opinions have shifted drastically as my knowledge has increased.

I would suggest visiting Larry Kosilla's website and listening to the last two podcasts which feature Kevin Brown and Jason Rose. In both podcasts they touch on the subject we are discussing here and perhaps can argument my points.

At the end of the day, large diameter orbital polishers have represented a paradigm shift in the way orbital polishers work and operate. The majority of the friction necessary for polishing paint comes the orbital movement, which reduces (and can eliminate) the need for pad rotation.

I am not stating that rotation doesn't offer benefits (it does) but it is not necessary to correct the finish. My statement was that "if it ain't rotating it ain't correcting" is no longer correct. The orbital movement alone of a large diameter orbital tool produces enough movement to correct the finish alone (although perhaps not always in the most efficient manner).

Well... all we can hope then is your 'guilt' will win out and you'll find the time to read it all.

Ahhhh.... yes.... I'm aware that you once said rotary was the only way, thing is..... folks had already been way ahead of the curve there and were correcting with orbital machines.

[quote=Todd@RUPES;1315050]
The 21mm BigFoot generates 90% or more of it's total pad speed from the orbital movement of the pad./QUOTE]

Weeeeelllll.... maybeeeeee more than a little less than 90% according to my calculations.
Maybe you didn't have time to read this part.

Considering that the 12 and 15 gain 38% more pad speed at 2.5 RPS, it’s interesting that the 21 has a full 36% increase in and of itself! Sure, slowing that down to 2 RPS would drop that a bit, down to 29%, but that is still significant indeed.

Just don't think we're (paint polishers as a whole) ready though to do correction without pad rotation. Call me ol' fashioned, or call the Rupes engineers ol' fashioned.... because it is clear that *somebody* has decided that oscillation with rotation (rather than without) is needed (or at least enough of a selling point) to have an "EVOLUTIONARY", (Dylan's word) improvement.

Enough so in fact that a new design and acronym, "MkII" was born.

The additional rotation comes from the machines ability to maintain ORBITAL motion under load. It is the inertia of the orbital movement (and a host of other factors) that create the spinning motion. However, most of the additional cutting power is going to come from the ability to maintain orbital motion under load.

Most of that, new "inertia" would surely be from the centripetal force generated by a redesigned weighting system, as well as higher RPM. Remember that is action being forced to rotate upon a given arc (without moving outward as with centrifugal force).

Still would be interesting to see the calculations of pad speed - - - gained, lost and equalized along the orbit as the rotational path is followed and how that translates to machine speed. ESPECIALLY at each (OPM/RPM) setting, say 3, 4, 5, 6 etc.

Considering with a 8mm orbit you will lose hardly any calculable speed (due to the small orbit) where as you move to 12mm, 15mm, and 21mm it'd surely come into play, albeit less as the rotational speed increases. All that math is SURELY over my head!

Would be interesting to do a side by side test, on a 2000 grit sanded panel.
One machine with the pad locked down, zero rotation.
One machine with the pad spinning at 120 RPM.
One machine with the pad spinning at 240 RPM. (Which is generally faster than we'd all allow a DA machine to spin.)

FWIW the new 21, with the faster OPM, say at 5000 OPM would be running an orbit pad speed of 12.3 MPH!

Where the rotational speed, staying at 150RPM is still 3.12MPH which now is a smaller percentage of gain to the overall (pad to paint) "P2P" speed. Basically it's now a 25% increase, instead of 36% when the machine speed is only 3500 OPM. Still quite an addition to the overall pad to paint contact however.

Guess what I'm getting at is as long as you're doing really high OPM, on a large stroke machine... the RPM benefit is lessened more so than when running more conservative OPM speeds.

That in and of itself however opens another can-o-worms when you start looking at friction generating heat within the pad, as well as between the pad to backing plate Velcro connection. That area alone generates massive amounts of heat, as the Meguiar's engineers found on their first gen DAMF pads... which were failing in that area BECAUSE of pad to plate generated heat, causing a reengineer of the "system". Which is also why I mentioned earlier the Rupes Velcro, as it's particularly 'grippy'. (Which is a GOOD thing when you're trying to control heat in that area.)

Still however... higher OPM speeds will absolutely generate higher heat readings within the pad, much more so than running lower OPM and having higher RPM. Which is easy enough to check by either doing it slower then faster and using an IR thermometer, as well as just using a rotary versus an orbital and noticing how the rotary pad doesn't get (dangerously) hot at the backing plate (especially at the center) where the orbital pad does. Although the MPH or P2P speed is MUCH faster than any orbital will EVER be.

For instance, a 7" pad running at only 1000 RPM would be almost 21MPH!
Which is no wonder you see holograms from the old school body shops running a 10" wool pad, (which at the same RPM is running a whopping 30 MPH P2P speed!) Holy Moses!!!!

[225]

Mid-December. I'm new to detailing, but I'm waiting for the mark 2 to be released before I buy a polisher.

[Todd@RUPES]

Well... all we can hope then is your 'guilt' will win out and you'll find the time to read it all.

Perhaps I'll find the time. At the very least I would like to response to the points I find pertinent, but then you go and post this, taking up what little time I have.

Ahhhh.... yes.... I'm aware that you once said rotary was the only way, thing is..... folks had already been way ahead of the curve there and were correcting with orbital machines.

Of course, luckily I was able to learn form one of the pioneers in this field early on and was taught a valuable lesson... seek knowledge from those more learned or experienced. It has been instrumental in my life.

Weeeeelllll.... maybeeeeee more than a little less than 90% according to my calculations.
Maybe you didn't have time to read this part.

If I release all pressure on the pad and let it free spin quickly, I can generate much more speed from rotation. However, as applied to the paint and considering the total surface area of the pad, at least 90% (typically) of the total movement will come from the orbital movement.

Of course, none of this really matters because as you have also demonstrated, a large majority of the pad movement (and thus potential polishing friction) comes from the orbital movement. You asked to me to clarify my statement "it doesn't have to be be rotating to correct paint" which your math and many people's experience clearly does.

Just don't think we're (paint polishers as a whole) ready though to do correction without pad rotation. Call me ol' fashioned, or call the Rupes engineers ol' fashioned.... because it is clear that *somebody* has decided that oscillation with rotation (rather than without) is needed (or at least enough of a selling point) to have an "EVOLUTIONARY", (Dylan's word) improvement.

Rotation is beneficial in most circumstances. Excuse my skepticism but you haven't presented any case that rotation is necessary for correction.

Enough so in fact that a new design and acronym, "MkII" was born.

It is an upgraded design and thus needed a new name.

Most of that, new "inertia" would surely be from the centripetal force generated by a redesigned weighting system, as well as higher RPM. Remember that is action being forced to rotate upon a given arc (without moving outward as with centrifugal force).

I'm not an engineer but luckily I have had very long discussions with the engineering team in Italy as well as the excellent engineers we have state side.

I am not sure what you mean by a redesigned weight system and why you feel this is necessary for pad rotation. There is no offset on the shaft side (post bearing) that is causing the pad to whip around.

I agree with the thought of centripetal force imparting rotation because the outer edge of the pad would have more force making it "fall in". However, the engineers I have spoken with assured me that this was not the case. I confess I still don't understand it completely.

If the bearing had zero drag and the rotating assembly (pad/backing plate) the pad would not rotate in free air.

Still would be interesting to see the calculations of pad speed - - - gained, lost and equalized along the orbit as the rotational path is followed and how that translates to machine speed. ESPECIALLY at each (OPM/RPM) setting, say 3, 4, 5, 6 etc.

Considering with a 8mm orbit you will lose hardly any calculable speed (due to the small orbit) where as you move to 12mm, 15mm, and 21mm it'd surely come into play, albeit less as the rotational speed increases. All that math is SURELY over my head!

Far over my head too but the orbital speed is fairly constant. So when you consider the vector velocity of a point on the pad its fairly constant. Even when the orbit is moving 90 degrees away or towards center (when its velocity relative to rotation is slowed) it is still generating work as it moving away or towards the center at a fairly constant rate).

Ultimately the math for a random orbital is pretty simple. Calculate the distance traveled by the orbit x the number of orbits, the distance traveled by the rotation x the number of rotations, then convert. Then we can calculate the movement in MPH, Km/S, M/S or any other d/t rate.

Yes the speed relative to the rotation would fluxuate higher and lower than the average but I believe even this is fairly constant. If the MPH of the orbit is 10 and the rotation is 3, then at it's slowest point relative to rotation it should still be traveling 7 mph, and at the fastest point (furthest away from pad center) the orbital speed would be added to the rotational speed (for that brief moment when the orbits vector and the rotational vector are identical) so it would be 13 mph.

I'm not a math major, nor an engineer, nor a physics guy, but it makes sense in my head.

Would be interesting to do a side by side test, on a 2000 grit sanded panel.
One machine with the pad locked down, zero rotation.
One machine with the pad spinning at 120 RPM.
One machine with the pad spinning at 240 RPM. (Which is generally faster than we'd all allow a DA machine to spin.)

Of course, but with a random orbital it would require less pressure to generate a higher rotation, which would skew the results.

FWIW the new 21, with the faster OPM, say at 5000 OPM would be running an orbit pad speed of 12.3 MPH!

Also there are times when less pad speed will generate more cut because of external factors such as abrasive loading. None the less, a fun test for sure. However, none of this has anything to do with the original point in which you asked me to defend.

Where the rotational speed, staying at 150RPM is still 3.12MPH which now is a smaller percentage of gain to the overall (pad to paint) "P2P" speed. Basically it's now a 25% increase, instead of 36% when the machine speed is only 3500 OPM. Still quite an addition to the overall pad to paint contact however.

Guess what I'm getting at is as long as you're doing really high OPM, on a large stroke machine... the RPM benefit is lessened more so than when running more conservative OPM speeds.

The further we go towards the pads center, the more we rely on the orbital movement. Even with high pad speeds on the edge, its hard to generate a huge amount of movement (relative to the orbital movement). Most of the cutting potential comes from the orbital movement and the pad's ability to deliver that movement to the paint.

That in and of itself however opens another can-o-worms when you start looking at friction generating heat within the pad, as well as between the pad to backing plate Velcro connection. That area alone generates massive amounts of heat, as the Meguiar's engineers found on their first gen DAMF pads... which were failing in that area BECAUSE of pad to plate generated heat, causing a reengineer of the "system". Which is also why I mentioned earlier the Rupes Velcro, as it's particularly 'grippy'. (Which is a GOOD thing when you're trying to control heat in that area.)

Still however... higher OPM speeds will absolutely generate higher heat readings within the pad, much more so than running lower OPM and having higher RPM. Which is easy enough to check by either doing it slower then faster and using an IR thermometer, as well as just using a rotary versus an orbital and noticing how the rotary pad doesn't get (dangerously) hot at the backing plate (especially at the center) where the orbital pad does. Although the MPH or P2P speed is MUCH faster than any orbital will EVER be.

Orbital movement creates heat inside the pad because of the lost movement (energy) that never makes it the paint. It is the flex and twist inside the pad (or the forces wanting to flex and twist) that covert to heat energy. You are absolutely correct about the necessity for a strong sheer strength in the hook and loop, as movement from the backing plate would be lost in "wiggle" and the heat created would be tremendous.

As stated about, when I used the RUPES coarse blue foam (which is laterally very stiff and has a large cell structure to allow heat to escape)to remove sanding scratches without pad rotation, the paint was very warm (maybe too hot) but the pad was relatively cool to the tool. Even though the pad was rotating, there was very little energy lost in the pad (do to tilt and pressure) and the pad remained cool.

This can even be experienced on the very stiff UHS foam. If primed according to RUPES' recommendations (6 drops, speed 3, firm pressure for 30 seconds) the face of the pad will become warm and very soft but the majority of the foam will remain stiff and cool. This is what will allow the pad to cut and polish the same time.

It seems that you agree with the statement that rotation isn't necessary for correction, so I am baffled why the conversation continues to grow. However, if like me, you simply enjoy a good, well argued debate, then at this point I would ask you to move it PM's and lets return this thread to it's topic so others can ask questions on the Mark II vs the original design..

Ultimately, the Mark II will generate both more orbital speed and maintain that orbital speed under load, which results in more pad movement, which results in faster correction That is what this thread is about.

[kosmetikwerks]

Id like to say thank you both Todd and Dylan for these responses takes a lot of time sifting through and replying in depth to each and every question. Loved the mk1 and fully intend to snag up latest and greatest mk2 machines when they become available!