Flex 3401 or rupes bigfoot.

Im getting my rupes next week...
I had past experience with the 3401... it kept walking on me.. so i didnt like it and i sold it....

Hopefully the rupes will be the one for me....
 
ww2717 said:
I could stop my lhr21 from rotating before the KB mod. After the KB mod I can't stop it even on setting 1.

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Why would you have to mod a brand new machine that was supposed to be well thought out but now you did something to make it work...

Crazy Diamond said:
At this point in time it appears the flex is still leading the way!
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Now people are modding the RUPES to make it work. Flex works right out of the box and has a more powerful motor... Thats a win in my book.

fenderpicks said:
Im getting my rupes next week...
I had past experience with the 3401... it kept walking on me.. so i didnt like it and i sold it....

Hopefully the rupes will be the one for me....
Click to expand...

Some people like it and others dont. What pads were you using with it?
 
Rupes works really well with meguairs and optimum MF 6.25 " pads both cutting and polishing. Foam I have only used chemical guys hex logic 6" foam pads in orange, green ,gray and black. Compounds that have been used with the lhr21es so far are sonax Profilline Fine Abrasive Polish, Perfect Finish, Nano Polish, Menzerna FG400,SIP,106FA, PO85RD, Meguairs M101, M105,M205,D300 and D301.

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smack said:
Why would you have to mod a brand new machine that was supposed to be well thought out but now you did something to make it work...


Do you mean like switching to smaller bp's on the Flex to meet the various demands of detailing ?
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2old2change said:
Do you mean like switching to smaller bp's on the Flex to meet the various demands of detailing ?
Click to expand...

I wouldn't consider changing the BP a mod. You are adapting the tool to the task at hand. Now if you are doing anything more to the machine to modify its performance then that would be considered a mod in my book.

What is the KB mod on this machine anyways. I keep hearing about it but no info to support it???
 
smack said:
I wouldn't consider changing the BP a mod. You are adapting the tool to the task at hand. Now if you are doing anything more to the machine to modify its performance then that would be considered a mod in my book.

What is the KB mod on this machine anyways. I keep hearing about it but no info to support it???
Click to expand...

Yup, it's a huge mod alright...in the same way lubricating the felt ring on a 3401 is a huge mod...

Kevin Brown said:
Marco (the Rupes® engineer that developed the machine) explained that excessive rotation could cause scouring of the polishing surface if the backing plate and buffing pad were allowed to freewheel spin prior to contacting the polishing surface. He also mentioned that excessive rotation was considered to be a safety hazard in some parts of the world. Understanding his reasoning, I nevertheless decided to install a spacer between the backing plate and mounting pad in hopes of restoring a maximum amount of backing plate rotation.

With the spacer installed, backing plate rotation increased immensely. While I was not able to verify exactly how big an increase occurred in terms of backing plate rotation or cutting power, I can say that it was a LOT. My best guess: backing plate rotation increased to 10-14 times per second, and cutting speed increased by about 50 percent.
Click to expand...
 
The KB mod is extremely simple but highly effective mod. I want to see if the other mod of upgrading the onboard ASIC chip rom firmware has as KB mod does.
 
I'm getting my rupes 15 this Thursday
Now is time to get rid of my pc7424xp and griot 6"
 
At this time the market is being flooded with used da's from those switching to the Rupes. I view this as a win/win sitution for many. Especially those wanting to step up to a Flex or Griots but were looking for a bargin. For those moving to the Rupes their seems to be plenty of buyers seeking the used machines. :dblthumb2:
 
Hello,
Is there anyone that can post a picture of the modification,and what you used as a spacer.Any help would be appreciated.
Matt
 
What exactly make the Rupes so much better than the other DAs?

Is is the larger throw?

I agree that the Flex 3401 is a good machine, but it's not the most pleasant to operate. It was the first polisher I bought, for the time I thought it wasn't too bad to control, but after using rotary for the last year and having tried the 3401, it is definitely evident that you have to "wrestle" the machine in many situations to keep it controlled. It's not too bad if you don't do that many corrections, but if it's something you plan on using daily, the fatigue could become a problem because the large throw, the dual action, and the forced rotation are not the most used friendly.
 
BucboyInPa said:
Hello,
Is there anyone that can post a picture of the modification,and what you used as a spacer.Any help would be appreciated.
Matt
Click to expand...
From a Kevin Brown post on another blissful detailing site:


And...I QUOTE:
____________________________________________________________________________________________________

"The Bigfoot has tremendous cutting ability".

"The Bigfoot’s 21mm stroke creates loads of centripetal force at speed, and its spindle bearings allow the backing plate to spin along unabated. Consequently, random rotation of the backing plate should be out of this world! However, a purpose-built shroud not only covers the driveshaft-mounted rotating components, but also slows backing plate rotation via drag-induced friction.

Marco (the Rupes® engineer that developed the machine) explained that excessive rotation could cause scouring of the polishing surface if the backing plate and buffing pad were allowed to freewheel spin prior to contacting the polishing surface. He also mentioned that excessive rotation was considered to be a safety hazard in some parts of the world. Understanding his reasoning, I nevertheless decided to install a spacer between the backing plate and mounting pad in hopes of restoring a maximum amount of backing plate rotation.



A metal, plastic, or phenolic washer will work. Cut and sand to size.

spacer-for-backing-plate-.jpg





The height of the spacer needs to be enough so that the backing plate will no longer contact Bigfoot’s shroud.
The spacer shown is approximately 3/16” tall and was taken from a backing plate featuring a 5/16”-24 mounting stud.



The spacer was placed between the backing plate and mounting pad.

rupes-lhr21-counterbalance.jpg


rupes-lhr21-washer-installed.jpg



The pad still mounts safely and securely. If desired, a minimally longer bolt can be installed to compensate.
The bolt is 8mm. The shape of the platform and spacer is known as a Double-D cutout.



The resultant gap is nearly unnoticeable.

rupes-lhr21-gap2.jpg



With the spacer installed, backing plate rotation and cutting speed were dramatically increased.
The difference was apparent, even when low speed settings were used.





With the spacer installed, backing plate rotation increased immensely. While I was not able to verify exactly how big an increase occurred in terms of backing plate rotation or cutting power, I can say that it was a LOT. My best guess: backing plate rotation increased to 10-14 times per second, and cutting speed increased by about 50 percent.


If a rotary buffer outfitted with a wool pad had any sort of performance advantage over the Bigfoot, the advantage was nearly or completely negated after this easy to implement modification. This newfound cutting power elevates the Bigfoot to superstar status. I hope that Marco will not be overly upset by the addition of the spacer, and I am sure he is aware of the tremendous rotation potential of this machine (otherwise there would have been no need to design the shroud to contact the backing plate). Regardless, I plan on using my machine with a spacer installed.


Whereas a machine such as the Meguiar’s® G110v2 Dual Action Polisher (8mm stroke, 6,800 OPM max) requires that a 5” DA Microfiber Disc be used in order to maximize polishing performance, the Bigfoot delivered equal or faster results using the 6” discs. Compared to a 5” disc, a 6” disc offers up more surface area, increased stability, longer working time, and higher rotational speed along the edge of the disc.

In the end, it’s likely that most guys won’t add a spacer between the backing plate and mounting pad. I’m not even aware of whether such a thing will cause a warranty issue. Regardless, as long as the balance or motion created by the Bigfoot is not negatively affected by the design or weight of the buffing pad, the Bigfoot will perform on par or better than a typical random orbital that has been outfitted with smaller diameter pads".
____________________________________________________________________________________________________


[FWIW: Please take note of the: "unknown warranty-issue"...in the last paragraph.]

Hope this is what you were looking for.

:)

Bob
 
Thanks Bob,
I appreciate that.Just waiting for my Rupes to get here now.Will post some pics soon.
Matt
 
Thanks for posting Kevin's mod Bob, I'm going to ask the R&D Manager from RUPES about this in a couple of weeks when I meet with him. Seems like if this modification improves the performance and there are now down sides then RUPES should implement the fix at the factory. I'll ask and see if they already plan to do this and if not then why?

I'll share back here what he says...


:)
 
Mike.Phillips@Autogeek said:
I'll ask and see if they already plan to do this and if not then why?
Click to expand...

My guess is for the sander application where overspeed would be more of an issue (gouging on first touchdown in the scenario Kevin describes of turning it on when it's not on the surface) and the shroud contact may keep sanding dust out of the insides.
 
Mike.Phillips@Autogeek said:
Good guesses!
Click to expand...

I'm pretty sure you already knew that, I guess if the polishing version is a different part number (a la PC) then they MIGHT change it for that model by putting a washer in...but I don't consider that likely...you know these corporate politics...

Kind of funny really, if this becomes a "standard" mod, either from the factory, DIY, Kevin Brown, or Autogeek, we will be back to those threads "My Rupes doesn't seem to have the power I expected" and the answer will be "do you have the backing plate washer on?" just like with the PC etc.
 
It appears to me that the DA/RO-advances now being launched, and lauded, are taking the
enthusiasts/hobbyists/weekend-warriors further and further away from the factors-of-safety
that a PC/GG/G110v2-style "buffers" promises to supply...

Is the trend now to attempt to remove "defects" from the top-coat paint-film (usually CC) by:
-'Paint-film'-removal...As quickly, and...Over as large an area as possible...At the same time. And:
-With the new aggressive compounds now on the market?
-Without causing 'harm' to said paint-film...
-Even going as far as to overriding/modifying a manufacturer's engineering standards?

Perhaps this could be considered training for upgrading ones skills-set
towards being proficient at 'rotary-buffing' someday.

No matter what ones choice in "buffing-machines" may be...
I still beseech folks to be cautious..

Just a couple thoughts of mine.

:)

Bob
 
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