As much as I love the forums, there's no denying the power of Facebook. A lot of chatter regarding the BigFoot, so I figured I'd copy and paste some of it here (this way it'll be easier to find down the line). For the record, the entire thread can be found
here, and was based off of a thread started here.
Rupes LHR 21ES: "The King of Cut"
Lots of discussion about the
Rupes® BigFoot 5"
LHR15ES versus the 6"
LHR21ES.
"Are the backing plates interchangeable?"
"Can I use the 5" plate on the 6" machine?"
"Which is the best one?"
The backing plates ARE interchange between the machines.
The hard plastic portion of the plates are the same exact HEIGHT.
The 5" and 6" plate WEIGH nearly or exactly the same:
Repeated weigh-ins of the 5" plate showed a variance of 0-6 grams.
Repeated weigh-ins of the 6" plate showed a variance of 0-6 grams.
Rupes 5" buffing pad.
Rupes 6" buffing pad.
The blue & gray plastic portion of the backing plates measure:
5" plate - 117mm diameter / 6" plate - 130mm diameter
• The Velcro portion of the plates measure:
5" plate: 125mm or 4-7/8" actual / 6" plate: 148mm or 5-7/8" actual
• The white foam is 12mm tall on the 5" plate.
Its side features a somewhat squared side, flaring only 4mm top to bottom.
• The white foam is 9mm tall on the 6" plate.
Its side features a somewhat flared edge, flaring 9mm top to bottom.
So... there won't be any "balancing issues" due to weight variance. However, should you decide to swap the 5" plate onto the 6" machine, it will FEEL different
partly because the plate's foam sections are not similar at all (plus other reasons, to follow).
Continuing on with the 5" plate on the 6" machine:
The 6" LHR 21ES may not FEEL as balanced as the 5" LHR 15ES because there is 40% more "throw" or "offset" with the 6" machine. In addition, the 6" machine utilizes a heavier counterbalance assembly, which compensates for the larger stroke (and perhaps a bit for the potentially heavier pad). The added counterbalance weight is not an issue unless you happen to REALLY be throwing the machine about or; the extra weight may cause more of a steering sensation (if you've ever ridden a "wheelie" down the street on a bicycle and turned the handlebars while the front wheel was spinning, this may make sense). Not really an issue, just something technical I thought about while writing this.
Otherwise, the added weight keeps the backing plate spinning along FASTER and MORE CONSISTENTLY as regular polishing or added friction is encountered (due to panel shapes changes, applied pressure, etc.) This was VERY noticeable during a mini-test session last night. The 6" machine SMOKED the 5" machine in terms of backing plate rotation, and under heavy applied pressure (to test the premise), the 6" machine was the clear winner in keeping the backing plate spinning. Keep in mind that the 5" machine is rated to deliver 5,000 RPM versus 4,200 RPM for the 6"..!
Which machine should YOU choose?
While all of the above SEEMS to show the LHR 21ES as being the clear choice, it was not my intent to make that choice for you. I'm merely stating what I saw to be true. Factually, I think that so many guys are used to using a 5-1/2" pad or disc nowadays, that they may want to stick with the 5" machine for financial reasons (some guys have 100+ 5" pads!), or simply because they're used to using the 5" pad. I think both are great reasons to buy the 5" machine.
It is also true that all other things being equal (machine speed and specs, pads), a machine with a small stroke will FEEL smoother or more balanced (even if its not actually better balanced) because there is less "side bashing" of a pad against a hood bulge, a sharply curved plastic bumper, a body trim piece (or whatever). Or maybe not! A smaller pad means that the platform the machine is riding on (the pad) is less stable because it is not as large or wide (so a tilt of the machine or an encounter with a hood bulge may feel more "bashy" or "abrupt").
I could go on and on, but I wanted to at least relay the fact that the 5" plate
will fit on either machine, and depending upon the pad to stick against it... you
may or
may not feel a "balancing" issue.