How to keep your most important tool in peak condition

Has your flex shaft ever seemed to run too hot? Or has it started making a weird grinding noise?

Wait a minute, when was even the last time that you paused to do any maintenance on it? Most flex shaft motors are made to run for years and years with minimal intervention, but they do need a little TLC.

Maybe it’s been a few years, and that’s OK – this is a judgment-free zone. Until about 7 years into being a metalsmith, I didn’t even know that this was something that you could maintain. I had to learn it from a co-worker at the time, and I want to share with you the top two ways that you can get your flex shaft purring like a kitten again.

Watch this video here, or follow the instructions below:

First up, Have a look at the motor housing – that’s the main, bulky part that hangs. Make a note of what model you have – this will be important for finding the right parts for your machine. On the side, probably right next to the hanger, you’ll see a black circle on both sides, most likely with a groove through the center. Found it? Great! Here’s what you do:

Tip #1 – replace the motor brushes

• Using a standard flat head screwdriver, unscrew this part and just know that a part will come popping out.

  • This is the motor brush and it is attached to a spring.

  • (It’s called a brush, but it really looks like a small brick of graphite.)

  • Examine the motor brush – does it look worn down? Is it less than a quarter of an inch? If it’s less, then it is unlikely that the motor brush is the issue.

  • Wear on a motor brush is normal over time. This part is there to manage friction on the motor movement.

  • If it looks normal, then replace the motor brush just how you found it and screw the cap back on. If they look too short or worn down, replace them with new motor brushes. Do this on both sides.

  • New motor brushes are usually under $15 for a pair – think about it, your Flex shaft may have been $300, but for just $15 you could make it brand new again!

Tip #2 – Lube the shaft (Seriously this is the technical term for it)

• Grease it! Here’s how:

  • First, take off the handpiece. Most flex shafts you can simply pull it off

  • Look at the part just below the motor housing – where the shaft meets the motor.

  • Do you see a little screw on the side? Use a small screwdriver (for some models you’ll need a small Allen Wrench) and unscrew it. Be sure to set it aside in a container where you can easily find it again.

  • Now slide the entire rubber sheath off. This will reveal the long coil of the shaft underneath. This is the part we need to grease.

  • Take a lint-free cloth (I like an old T-shirt for this) and wipe down the shaft (the coil part). It’s normal to see some dirt or grime on there.

  • Then take a different lint-free cloth (Or a cleaner part of the same cloth) and use it to add more lube to the shaft. Start at the top, near the motor housing, and work your way down.

  • Reattach the rubber sheath and the set screw, put the handpiece back on and run the motor to see how it sounds.

Voila! A couple of simple things you can do, that will take less than 30 minutes and cost very little, all to maintain a machine that makes your life so much easier.

Let me know in the comments if you have any questions!