[Eurogloss]

Haven't posted for a while because of health issues !

Full Review and Testing of the Flex XC 3401 VRG

After one month of extensive testing of the Flex XC 3401 VRG here are my impressions on this machine.

Out of the box this machine feels and handles like a rotary polisher it also tends to runaway from you like a rotary does, the torque and power are impressive!

General design & ergonomics; very pleasing to the eye with the red and black body design. The design is very high tech typical of these German power tools as is the build quality which is excellent!

Because I am used to Rotary Polishing it did not effect me at all. However it did take some practice to polish with this machine, but afterwards it was like using a

Rotary. Compared to Porter Cable, Meguiar's G220, UDM and Cyclo machines it literally obliterates them !

When you compare it to a Makita BO 6040, Festool RO 150 FEQ , RO 125 FEQ, and RO 150 E it works in a similar way with constant forced rotation, but the other four machines can be switched from random orbital to forced rotation .The Festool machines are Sanders not polishers ! Flex is far superior in power and torque; nothing comes close!

The Flex cannot be switched to RO; it works in forced rotation only.

According to Flex this machine was designed for polishing and nothing else; that's what it does best.

With a 900 watt motor and an 8 mm throw this machine will do what a rotary does.

Even if a bit slower (but not that much slower !). Considering it spins at only 480 rpm max speed, it will do paint correction. The majority of polishing jobs I did were done with this machine, no rotary was used except for a job that I did last Friday Mercedes Benz CLK 240 in Zircon Silver . I used a combination of Rotary and Flex.

I also compared the speed of correction how these machines polish, first up was my rotary, it eliminated deep scratches very quickly but left very fine holograms which I went over afterwards with Rotary & Flex . All gone! No swirl marks whatsoever!

I tried to bog this machine down to see if I could stop it but without success; it kept on going and going! At one point I was trying to remove a very bad scratch from the boot of this car and I put pressure as you would when you are removing a deep scratch , anyway , I managed to generate a tremendous amount of heat to this area so I had to back off immediately!

This does not normally happen when you are using a Random Orbital with forced rotation, a Rotary Polisher is the only machine that I know of that will create this heat build up!

Mercedes Benz use the the Flex XC 3401 VRG on their assembly line to achieve that glossy finish on all there motor cars.

I tested this machine on a number of paint finishes from single stage, to clear coat paints, to the latest Nano Ceramic Scratch Resistant Paints. Ideally I would use a rotary polisher to correct severe paint defects like scratches, swirl marks, wet sanding scratches, but with the Flex you can actually correct all theses really bad paint problems without the use of a rotary ! I know there are skeptics out there that would argue the opposite.

I deliberately inflicted wash marks using a 3M Scotch Brite on a test panel; I also used a 3M 1500 grit wet and dry to create sand scratches then I used a piece of metal to create severe scratches, the Flex corrected almost 99% of all these paint defects without a problem.

No swirl marks whatsoever! Flawless finish and very high gloss paint finish!

These are characteristics that a rotary has when creating a very high gloss finish!

With the Flex XC 3401 VRG you can eliminate the paint defect.

And to correct these paint defects the Flex's speed has to be set at 480rpm to get these results that is the maximum speed. Otherwise it won't cut the paint!

One feature I really liked was the variable speed trigger which allows you to feather touch the speed for applying waxes, polishes, and compounds and for those very delicate paint areas that need a reduced speed.. After you have selected the desired speed you can lock it in with the electronic speed dial control.

When selecting buffing pads, either Flex or Lake Country, make sure the pad is centered properly otherwise the machine will vibrate a lot (especially at full power).

Noise: because it's forced rotation and direct drive you will get that typical whining of these power tools (Festool Rotex RO 150 FEQ) but in a more balanced way.

Please note: due to the high pitched noise it is advisable to wear ear protection at all times whilst using this power tool.

Feel of the machine and ergonomic design: it feels like a rotary; the electronic speed control dial is on the left hand side; the bale handle is also very useful as it gives you more control when polishing lager areas as well as very small areas.

The fact that it's got a proper handle (like a rotary) was a pleasure to use.

Long periods of polishing were no problem with this machine however, it is advisable to take short breaks.

Electronics: Flex's seven fold microprocessor electronics: with consistent speed control by tachometer generator (Speed Dial Control) soft start, accelerator trigger switch, restart protection after power interruption, over load protection, temperature monitoring and speed selection.

8mm orbital movement

Permanent direct drive for an even polished surface

Removable ergonomic knob grip

High-powered motor: can handle extreme loads

Spindle lock

Quality shut off carbon brushes: if the carbon brushes wear down, the motor will automatically switch off and thus protected from damage.

Technical specifications: Flex XC 3401 VRG

Max. polishing pad diameter 160 mm

Velcro pad 150 mm

Speed without load 160- 480 rpm

Orbit 8 mm

Orbit rate, without load 3200-9600 opm (rpm)

Power input 900 watt

Power output 590 watt

Weight 2.6 kg

Pros:

Plenty of power and torque

Corrects all shorts of paint problems (like a rotary)

Short learning curve compared to a rotary polisher

Will not leave swirl marks (depending on pad choice and polish compound)

Will leave a very high gloss finish like a rotary

Can be used by Professionals and Enthusiasts

Cons:

Will generate a lot of heat if left on a spot (like a rotary)

Can cause paint burn (although highly unlikely)

Can run away from you like a rotary

Vibrations can be a problem if pad is not centered (otherwise a very balanced machine).

You can only use one size Buffing Pad 6 inch or 6.5 inch at this stage, that was in 2008 ! Lake Country have developed this System !

http://www.youtube.com/watch?feature=player_embedded&v=jQEGQZpua7Q#

http://www.lakecountrymfg.com/products/features.cfm/catid/4/subcatid/30/lc--backing-plate-system

In conclusion, I find the Flex XC 3401 a brilliant power tool that will tackle everything that is thrown at it with polishing being it's forte and achieve what it's big brother (Rotary)does even if the speed is slower . In one word excellent!

I would highly recommend this power tool for the novice detailer to the seasoned professional without any reservations.

Paint defects ranging from wet sanding marks , to self inflicted scratches, to paint burn ! To a mirror finish no swirl marks or holograms whatsoever !

Colour Sanding marks 3M 1500 Grit paper !

Deep Scratches !

Deep scratches caused by steel wool

Wash scratches

After used Flex XC 3401 VRG with a Orange CCS Pad at speed six and Menzerna PO 85 RD 3.01 and PO 106 FF

New Lake Country 7" Kompressor Pads can be used with the Flex XC 3401 VRG ! They still need to be centered to get a vibration free polishing experience !

These cars were done with just the Flex XC 3401 VRG DA !

Flex has done it again!

Thanks for reading

Regards Mario

 

[honda-r]

Looks like it is a nice tool to have, safe (ish) tool and can achive paint correction.

 

[Eurogloss]

Yes it is ! It will do what a rotary does even if a bit slower !
As you can see from the pics it will remove severe to harsh paint defects .

I won't replace a rotary but it will complement it !

I am a rotary user but after using this machine for more than one month i am more than convinced ! I use both now , To achieve even better results !:buffer: :thumb:

 

[Bigpikle]

I like it and VERY nearly bought one BUT....you havent mentioned the fact that you cant change the backing plate. You are stuck with the 6"size only, making choice of pads a bit of a challenge and inflexible.

Otherwise I have no doubt it is a great machine, but I'm glad i went rotary in the end

 

[phil440]

I'm a rotary and DA man there isn't many cars Ive done where it isn't a combination of the 2, rotary for open easy to work spaces and DA for tight contoured surfaces and plastics IE bumpers

 

[superstring]

Interesting write up. However I'm curious about this statement:

No swirl marks whatsoever! Flawless finish and very high gloss paint finish!

These are characteristics that a rotary has when creating a very high gloss finish, you can't get this with a Random Orbital. Because these machines jiggle they can't generate enough heat to correct paint problems there for they give you an optical illusion they are removing the defect when in actual fact they are filling it !

How do you figure a RO "fills" defects? My understanding is it's the polish/compound that does the filling, not the machine.

 

[Eurogloss]

I like it and VERY nearly bought one BUT....you havent mentioned the fact that you cant change the backing plate. You are stuck with the 6"size only, making choice of pads a bit of a challenge and inflexible.

Otherwise I have no doubt it is a great machine, but I'm glad i went rotary in the end

Actually ,The Edge Buffing pads in USA are in the process of developing a system that will get rid of a backing plate all together and be able to fit and centre perfectly any pad size ! Here is the link !

Regards Mario

 

[swordjo]

Interesting write up. However I'm curious about this statement:

Originally Posted by Eurogloss

No swirl marks whatsoever! Flawless finish and very high gloss paint finish!

These are characteristics that a rotary has when creating a very high gloss finish, you can't get this with a Random Orbital. Because these machines jiggle they can't generate enough heat to correct paint problems there for they give you an optical illusion they are removing the defect when in actual fact they are filling it !

How do you figure a RO "fills" defects? My understanding is it's the polish/compound that does the filling, not the machine.

I agree with superstring, i've seen plenty of people on here to full corrections with a DA and not just fill the swirls, proven by doing an IPA wipedown. You can achieve full correction with a DA. As Dave KG has said on many occasions, he feels the only difference between a rotart and DA is the time and that a rotary gives a slightly crisper finish.

 

[Eurogloss]

Interesting write up. However I'm curious about this statement:

How do you figure a RO "fills" defects? My understanding is it's the polish/compound that does the filling, not the machine.

You are right ! The compounds fill . However , because a RO does not spin it oscillates or jiggles it doesn't generate enough heat to break down the polish and cut the paint there for it's pushing the product into the swirls or scratches that's why it's filling !

Perhaps if you use a wool pad you might get some cutting results !

Flex on the other hand works in forced rotation and generates enough heat to
eliminate the paint defect !:buffer:

 

[Deanoecosse]

Forgive me for being blunt, but your talking b0llocks about the DA not removing defects. The DA IS removing the defects by process of working the polish. The polish, being abrasive is cutting the paint and removing defects, not masking them. A simple wipe down with an IPA solution once you've fully worked the polish will remove any fillers which may be there and will reveal a defect free surface (if you've worked the polish correctly). You dont need heat to remove defects

 

[Dave KG]

Excellent review of the forced rotation DA - I used a Makita BO6040 (same idea, but switchable) and it was very good but I couldn't justify it into my detailing routine as I use rotary and DA extensively...

I must say I disagree entirely with you on the defect correction capabilities of a DA though. Correction (physical removal of paint) can happily be achieved by a DA, indeed it can happily be achieved by hand with enough time and effort. I have proved this many times in the past, either in actual test or during details that I have carried out extensively with a DA. The one that spring to my mind is this one on an Audi A4, corrected entirely by DA using Power Gloss and IP (no fillers):

http://www.detailingworld.co.uk/forum/showthread.php?t=7441

These marks were not filled by DA, they were physically corrected.

Further demonstration of hand, or indeed DA ability to correct by physical paint removal comes from the fact that these tool can strike through - and this has been demonstrated in test, and also a few unlucky members here have struck through by DA - they'll happily say they are removing paint, I am sure.

The differences are the speed at which a DA and a rotary can correct... A rotary breaks abrasives down more aggressive and will cut faster than a DA, but its speed thats the difference. DAs will struggle to fully break down harsh compounds, but they will still be cutting and they can happily break down finishing and medium polishes to give a finish on most paint types that will be a rival for a rotary machine if the tool is used correctly. On soft solid paints, the rotary may finish down just a little sharper owing to more consistent abrasive break down - but that is it.

Heat is an irrelevance to actual cut, simply a by product of the cutting process (friction) - but more heat does not equal more cut: try wool vs foam to see this. Higher cutting wool pads will correct more than foam, but run cooler.

Sorry for the essay there, but just felt it necessary to highlight that DAs can indeed correct paint, and they dont just fill as implied by your original post.

 

[superstring]

^ I think that about nails it. :thumb: Thanks Dave! Not to take anything away from the OP; still an excellent review.

 

[rob750]

Compared to a Porter Cable 7424 has the flex got less or more vibration ?

 

[legend_of_chaos]

I like it and VERY nearly bought one BUT....you havent mentioned the fact that you cant change the backing plate. You are stuck with the 6"size only, making choice of pads a bit of a challenge and inflexible.

Otherwise I have no doubt it is a great machine, but I'm glad i went rotary in the end

This is incorrect, flex have now made a 5.5" backing plate with foam inbetween the velcro and backing plate that they are sending to all flex purchasers.

 

[maesal]

I have the 5.5" backing plate and it works nice.

 

[ZoranC]

I like it and VERY nearly bought one BUT....you havent mentioned the fact that you cant change the backing plate. You are stuck with the 6"size only, making choice of pads a bit of a challenge and inflexible.

Not correct. First, backing plate is 5.5", not 6". Second, last half an inch of those 5.5" is soft foam that can be easily trimmed with scissors down to 5" so if you get spare bp you can have your cake and eat it too.

Further more, number of USA owners have trimmed down their bp on a lathe all the way down to central ring ending with 4.5" bp.

 

[Eurogloss]

Forgive me for being blunt, but your talking b0llocks about the DA not removing defects. The DA IS removing the defects by process of working the polish. The polish, being abrasive is cutting the paint and removing defects, not masking them. A simple wipe down with an IPA solution once you've fully worked the polish will remove any fillers which may be there and will reveal a defect free surface (if you've worked the polish correctly). You dont need heat to remove defects

I totally disagree with you ! Why on earth do professionals like myself and others rely more on rotaries than RO ? No disrespect to you or others on this forum but you do need heat to remove paint defects !

That's why more and more professional and enthusiasts use rotaries !

Flex is the closest thing that does what a rotary does !:thumb:

 

[Eurogloss]

Compared to a Porter Cable 7424 has the flex got less or more vibration ?

I have never tried a Porter Cable so i can't comment !
All i know any DA or RO that oscilates will cause some form of vibration even if more balanced !

The vibration is mostly caused by the pad not being perfectly centered !

 

[Eurogloss]

Excellent review of the forced rotation DA - I used a Makita BO6040 (same idea, but switchable) and it was very good but I couldn't justify it into my detailing routine as I use rotary and DA extensively...

I must say I disagree entirely with you on the defect correction capabilities of a DA though. Correction (physical removal of paint) can happily be achieved by a DA, indeed it can happily be achieved by hand with enough time and effort. I have proved this many times in the past, either in actual test or during details that I have carried out extensively with a DA. The one that spring to my mind is this one on an Audi A4, corrected entirely by DA using Power Gloss and IP (no fillers):

http://www.detailingworld.co.uk/forum/showthread.php?t=7441

These marks were not filled by DA, they were physically corrected.

Further demonstration of hand, or indeed DA ability to correct by physical paint removal comes from the fact that these tool can strike through - and this has been demonstrated in test, and also a few unlucky members here have struck through by DA - they'll happily say they are removing paint, I am sure.

The differences are the speed at which a DA and a rotary can correct... A rotary breaks abrasives down more aggressive and will cut faster than a DA, but its speed thats the difference. DAs will struggle to fully break down harsh compounds, but they will still be cutting and they can happily break down finishing and medium polishes to give a finish on most paint types that will be a rival for a rotary machine if the tool is used correctly. On soft solid paints, the rotary may finish down just a little sharper owing to more consistent abrasive break down - but that is it.

Heat is an irrelevance to actual cut, simply a by product of the cutting process (friction) - but more heat does not equal more cut: try wool vs foam to see this. Higher cutting wool pads will correct more than foam, but run cooler.

Sorry for the essay there, but just felt it necessary to highlight that DAs can indeed correct paint, and they dont just fill as implied by your original post.

Thanks Dave ,

I use Rotary and DA ( Flex XC 3401 VRG and Festool RO 150 E) as a professional ! Sometimes i use DA and nothing else it all depends on the job and the paint defect !
Why on earth does Meguiar's say you can't remove sand scratches with a ro ? Forgive me if i am wrong ! But don't you need friction to remove a paint defect ? By product or not ( of cutting , correction ) ?Also speed is very important !

 

[swordjo]

Thanks Dave ,

I use Rotary and DA ( Flex XC 3401 VRG and Festool RO 150 E) as a professional ! Sometimes i use DA and nothing else it all depends on the job and the paint defect !
Why on earth does Meguiar's say you can't remove sand scratches with a ro ? Forgive me if i am wrong ! But don't you need friction to remove a paint defect ? By product or not ( of cutting , correction ) ?

We get your point mate, YOU ARE A PROFESSIONAL, but what difference does that make. I removed swirls on my first go with a pc years ago, as have hundreds of people on this forum. And i'll think you'll find that some of the pro's on here still use a DA on certains cars where they feel they have to and still remove the defects. If you are only filling in the swirls on the parts of the car where you use the DA i'd maybe think about advising your customers that they aren't getting 100% correction when they could be if you knew a little more about the product you were using!