21 Mark II with 5 inch BP?

[MTCarNut]

Has anyone used a Rupes 5" backing plate on the Bigfoot 21 Mark II? If so, how do you like it? How does the machine behave with the smaller bp? What is Rupes official stance on this mod?

It would be nice to have the option of using 5.5"/6" pads for smaller panels where the 7" pads can be cumbersome. Definitely wouldn't want to risk damaging the buffer if the smaller bp puts too much stress due to higher rpms.

Dylan: Your thoughts on whether you think this is a good or bad idea very much appreciated.

[custmsprty]

Lot's of posts on this subject try the search feature, Dylan has also already commented on this subject. Search Rupes Mark II
:dblthumb2:

[custmsprty]

I just did a quick search Rupes Mk II and found this

http://www.autogeekonline.net/forum/rupes-bigfoot-oribital-polishers/103451-5-backing-plate-lhr21-mark-2-a.html

There are more, search is your friend:props:

[MTCarNut]

Thanks, didnt see that thread searching Google.

[custmsprty]

Thanks, didnt see that thread searching Google.

AG's search, upper right hand side of this thread page, the white block.

[RPM_BR]

I have a 21 ES, and when I put the 5in BP, it becomes a pad eater.
Obviously increases cut, it is like a turbo mode, but a lot more vibration as well, especially sideways vibration.
In mf pad, it generates such a heat that the pad's foam interface melts inside, like b&s black mf pad without center hole.
The Rupes 6in pads on a 5in BP on a 21 becomes convexed, and the center hole opens up like a cone, if you insist in using it. The Velcro durability shortens as well.
Rupes engineers were right when they decided the relation of offset and BP size, spot on.
I'm considering buying a 15 MKII, so I can use 6in pads.
Or buying a Chinese knock off, unfortunately, because a Rupes 15MKII will cost me 1000 bucks :(.
Best regards

[MTCarNut]

Thanks, think I'll save and just get 15 mkII down the road.

[rlmccarty2000]

Thanks, think I'll save and just get 15 mkII down the road.

Very good idea!

[custmsprty]

I have a 21 ES, and when I put the 5in BP, it becomes a pad eater.
Obviously increases cut, it is like a turbo mode, but a lot more vibration as well, especially sideways vibration.
In mf pad, it generates such a heat that the pad's foam interface melts inside, like b&s black mf pad without center hole.
The Rupes 6in pads on a 5in BP on a 21 becomes convexed, and the center hole opens up like a cone, if you insist in using it. The Velcro durability shortens as well.
Rupes engineers were right when they decided the relation of offset and BP size, spot on.
I'm considering buying a 15 MKII, so I can use 6in pads.
Or buying a Chinese knock off, unfortunately, because a Rupes 15MKII will cost me 1000 bucks :(.
Best regards

Great post and feedback.

The moral of the story, use the machine as it's manufacturer designed it to be used. Go outside their parameters and be prepared for the potential issues and don't complain to the manufacturer when the changes create said issues.

[Eldorado2k]

1 the main reasons I'm happy I ended up with a Boss G21.

[custmsprty]

1 the main reasons I'm happy I ended up with a Boss G21.

I'll have to second that, though I'm the owner of a Rupes LHR15, Duetto and Mini, I have a G21 and run it with a Griot's 5" interchangeable backing plate.

It's the machine I used to do this Z:

G21 with Griot's 5' BP
http://www.autogeekonline.net/forum/show-n-shine/98953-2014-nissan-370-z-griots-g21-hd-adapt-7-hd-poxy.html

[refreshauto]

I have a 21 ES, and when I put the 5in BP, it becomes a pad eater.
Obviously increases cut, it is like a turbo mode, but a lot more vibration as well, especially sideways vibration.
In mf pad, it generates such a heat that the pad's foam interface melts inside, like b&s black mf pad without center hole.
The Rupes 6in pads on a 5in BP on a 21 becomes convexed, and the center hole opens up like a cone, if you insist in using it. The Velcro durability shortens as well.
Rupes engineers were right when they decided the relation of offset and BP size, spot on.
I'm considering buying a 15 MKII, so I can use 6in pads.
Or buying a Chinese knock off, unfortunately, because a Rupes 15MKII will cost me 1000 bucks :(.
Best regards

What speed are were you using the machine. I have never had that issue running a 5" backing plate on the 21MKII. I have also never run the machine higher than a 3

[custmsprty]

What speed are were you using the machine. I have never had that issue running a 5" backing plate on the 21MKII. I have also never run the machine higher than a 3

My question is based upon that why have a machine that has a dial that goes above 3 if it's going to eat pads?

This constant want and our demand for more power has lead Rupes to make machines that you can't run BTTW (B*lls to the Walls) as we said in the USAF ( full afterburner) w/o eating pads or over heating. So what's the point with the increased power demand, right? I could blow out and fry pads with my 1st gen LHR15 w/o the so called needed "washer mode".

PS RF I agree with you 100%.

[refreshauto]

My question is based upon that why have a machine that has a dial that goes above 3 if it's going to eat pads?

This constant want and our demand for more power has lead Rupes to make machines that you can't run BTTW (B*lls to the Walls) as we said in the USAF ( full afterburner) w/o eating pads or over heating. So what's the point with the increased power demand, right? I could blow out and fry pads with my 1st gen LHR15 w/o the so called needed "washer mode".

PS RF I agree with you 100%.

Just cause the power is there doesn't mean you have to use it at all times. You need to learn how to use the machine properly. If not you have people talking about how the machines doesn't work like it's supposed to

[Eldorado2k]

I don't know if I have enough patience to run a polisher on speed 3. Doesn't it feel like driving a car @35mph. the whole time? I'd go crazy. Lol