Flex Cordless Random Orbital Polisher: Inside the FX3321

Cordless detailing tools have come a long way over the past several years. What was once a category dominated almost exclusively by corded polishers has steadily shifted as battery and motor tech continue to improve. Enter the Flex cordless random orbital polisher—a purpose-built tool that means business.

Looking purely at the specs, it appears to be a formidable contender, but we have a few questions to answer before we give our final verdict. With that in mind, we set out to discover what this polisher has to offer and what sets it apart from the pack. Is it the right tool for you? Let’s find out!

Buy from Acme Tools

Flex Cordless Random Orbital Polisher Performance

At its heart, the Flex FX3321 random orbital polisher houses a brushless motor and a variable-speed trigger with eleven speed settings ranging from 1,250 to 4,350 RPM. Bear in mind that the speed dial only goes to “6”, but there are positive stops between each number, bringing the total to eleven. I got fooled by this during my initial inspection and thought Flex made a mistake.

It also sports a 15mm orbit diameter and an orbit rate of 2,700 and 8,700 OPM. This is right in line with what we expect from Pro-grade polishers, if not slightly faster than some competitors like Milwaukee’s 2684 or Makita’s XOP02. This fast orbital motion is designed to efficiently remove swirl marks and scratches from your vehicle’s finish.

If you’re a little skeptical about retiring your tried-and-true corded polisher, Flex offers a familiar feel and performance to help smooth the transition. Moreover, its free-spinning random motion is more forgiving on paint, making it ideal for beginners and seasoned Pros alike. Plus, you don’t have to contend with a cord that’s constantly getting in your way.

Vibration

Vibration is a tricky subject for random orbital polishers, corded or cordless, because it’s simply unavoidable. The orbital motion and swift RPMs do cause a fair amount of vibration to travel through the tool body. The nice thing is that the rubber overmold provides enough grip that even when your hands are tired, you can still maintain a good grasp on the tool.

Flex Cordless Random Orbital Polisher Design Notes

Size, Weight, and Ergonomics

Shifting over to the tool’s design, this polisher features a slender grip and a large front pommel to help keep it steady while you work. The variable-speed dial is easily accessible during right and left-handed operation, and the lock-on button makes longer polishing sessions a breeze.

The Flex FX3321 weighs in at 4.6 pounds as a bare tool, 6.9 pounds with a 6.0Ah battery, and measures 15.2 inches from tip to tail.

As I mentioned earlier, the main grip area and front pommel are draped in a textured rubber overmold to improve comfort and handling. The texturing is pretty aggressive, but it really saves the day when your hands are sweaty and starting to fatigue.

As you might expect, the backing pad features a hook-and-loop attachment style that’s compatible with a wide range of pads and accessories. This interface makes it very easy to switch between polishing and buffing tasks in a matter of seconds. Flex also includes a second 5-inch diameter pad, adding to the overall versatility of this polisher.

Flex Cordless Random Orbital Polisher Price

The Flex FX3321 polisher retails for $599 as a bare tool and $749 as a kit. The kit comes with two 5.0Ah batteries, a charger, and a soft storage bag. Flex backs this polisher, batteries, and charger with a 5-year warranty.

Should You Buy It?

The Flex FX3321 proves that cordless random orbital polishers have reached a point where they’re a legitimate alternative to many corded models, and Flex has put together a well-balanced polisher that’s more than capable of producing impressive results. Considering Flex’s deep history in the automotive polisher segment, that’s not surprising.

The primary thing to consider is whether cordless freedom or unlimited runtime is the primary goal for the way you work. What’s not in question is the performance, so it really is a matter of preference between cords and batteries.

For the Pro who is full-time or part-time mobile, it’s an easy call. Cordless is king since you don’t have to worry about the customer having a nearby power source. You just need enough batteries to make it through the job.

For the traditional body shop, it’s a little trickier, since you’ll need two or three batteries to cycle on heavy polishing/buffing days. There’s a lot to be said for not having to manage the cord as you work around a vehicle, so the convenience factor is a big deal. On the other hand, if you’re trying to limit your upfront costs, it’s hard to argue with Flex’s corded options.

Buy from Acme Tools