My review of the Flex 3401 and Rupes Bigfoot polishers

[Harry Da Hamster]

I've had the chance to try both recently, the Flex 3401 and Rupes Bigfoot 15, and i just wanted to pass on my opinion and findings to those who may be in the market for a higher end orbital polisher. I rented the Flex 3401 and loved it compared to the GG and PC i tried. But decided to buy the Rupes 15 with no first hand experience based on all the hype. For all intents and purposes, the Rupes 15 and 21 are virtually the same. In a perfect world, the Rupes 15 and 21 smash the Flex 3401. The Rupes has a giant 15 or 21mm throw, and its non-direct drive meaning it would be virtually impossible to burn paint. Where as the Flex 3401 has a standard 8mm throw but is direct drive so the user can apply heavy pressure. Theoretically a non-direct drive long throw polisher would be all that we need for what were trying to accomplish. When polishing you shouldn't have to apply heavy pressure to the point where the Rupes would stall and the long throw would allow the polishes and compounds to work better as it abrades the surface with its long throw.

BUT in the real world we have various makes and models of cars of all different shapes. Curvacious vehicles like my new Cayenne have large sweeping concave panels throughout the vehicle on the lower half of the doors, on the D pillar, and above the headlights. This makes it virtually impossible to polish using a non-direct drive long throw polisher, a la Rupes 15 and 21. Even with the Kevin Brown washer mod, which essentially gives the polisher more power. In a concave panel situation, the long throw and non-direct drive work against each other and prevent the Rupes from orbiting.

Convex panels are a little better but still not as good as the Flex 3401. I noticed i didn't have the same stalling problem on the convex panels as i did with concave panels unless i used too much pressure. But the problem here is while using very little pressure, the contact patch of the foam pad against the panel is very small. Opposed to the Flex where i can use more pressure and buff out a larger area of the curved panel.

After trying to buff only a few panels of my Cayenne with the Rupes 15, i sold it and i'm considering a used Flex. So if you have one, message me!

Hope this review helps others to make a more informed buying decision.

Picture below to give you an idea where i had a difficult time polishing. Lower half of the doors, on the D pillar, and above the headlights.

[hernandez.art13]

Thanks for the review, so you picked the Flex, overall?

[Harry Da Hamster]

If you're like me and you only want one machine for all polishing duties, i would highly recommend the Flex and that's what i choose. If you have the budget for multiple polishers, the Rupes Bigfoot should be in your arsenal.

[Vegas Transplant]

Well said. Unbiased review.
Thanks for sharing this tool's limitations.
Often times we are so caught up in the hype, that we miss these snippets of info.

[VISITOR]

while the rupes 15/21 have a larger throw, the flex spins several hundred more times per OPM and with forced rotation so wouldn't that make up for the larger throw? i'm curious to here everyone's opinion...

[KillaCam]

Wish you would've compared the 21mm to the flex instead of the 15. A difference in a 6mm throw is a lot.

[freddie46]

Nice ride! I use a GG in my business and it's easy to stall it out with even the slightest pressure. The bottom line is I get good results. Interesting info on the Flex. I might have to try one.

[Gsrjake]

Yeah I would say the flex and the 21 would be more of an even review but what you're saying basically is that the flex is easier on those more awkward panels then the rupes? Thanks for taking your time and writing the review though I think I'm still gonna go with the 21 instead of the flex

[Kaban]

Yeah I would say the flex and the 21 would be more of an even review but what you're saying basically is that the flex is easier on those more awkward panels then the rupes? Thanks for taking your time and writing the review though I think I'm still gonna go with the 21 instead of the flex

From what I have heard, the Rupes pad stops spinning on weird angles. I guess it's ideal on flat panels, but like OP said, the world is not ideal and a good chunk of the panels will not be flat. Flex, I don't care how much you abuse it, will not stop rotating so you know you are getting the full correction without needing to adjust the angle of the machine/pad or go easy on the pressure which obviously will be detrimental to its correction ability.

If money is no an issue, obviously it would be ideal to buy/try all of them to see what works best for you and your needs.

[swanicyouth]

Thanks for the review and your thoughts on the machines.

I don't understand how people have issues with machines that "stop spinning". Yeah it can happen for a second, you just adjust you technique a bit. Maybe its because I learned on an old school anemic 7424 with 6.5" pads. I don't know, but I never really seen this as an issue.

My Rupes seems to spin faster/more torque when you put a bit of pressure on it. I've never had it "stop spinning" or really even slow down.