Flexshaft vibrating in the shaft itself

I just bought a new Fordom TXH flexshaft from Rio Grande, (Motor,
shaft, footpedal control, the 30H handpiece.) and I noticed after
assembling it that it is giving me quite a bit of vibration in the
shaft itself, regardless of speed. The shaft also gets a little bit
warm after 10 mins or so. I’ve checked the shaft for lubrication-
it’s fine. I wiped it down and re-lubed just in case. No change. I
checked to make sure it was properly assembled several times. I
checked the shaft itself for signs of wear or other problems. Nothing
wrong that I can find.

So here’s my question: Is this vibration normal? I’ve had a Dremel
before, and if a Dremel vibrates it means it needs lubricating,
especially if the shaft gets warm. Also confusing is that it will
occasionally run smoothly for a few moments before resuming the

Help? Advice?

Lindsay Legler,
Dreaming Dragon Designs

Hi Lindsay,

I recently upgraded from a Dremel to a Foredom too. I had the same
problem at first but soon realised that it was due to the extra
torque of the Foredom and the fact that I wasn’t used to it. For me
it was a case of getting used to the sensitive foot pedal and getting
the appropriate speed/revs for the job at hand.

Another thing which you’ve probably already checked is whether or
not the shaft has a good, uninterrupted path so that it can rotate


Hi Lindsay,

It’s hard to judge from a written description exactly what is
happening, but it seems to me that one possible cause of your flex
shaft’s vibrating MAY be overloading it, asking it to do too much. I
also have a TX, and I do use it hard - grinding alabaster with an
approximately 2" diameter wheel in the 1/4" handpiece and using the
desktop speed control. When I put pressure on the grinding wheel the
shaft jerks and stutters rythmically. Since there is elasticity in
the shaft I believe this is to be expected and constitutes a sort of
innate warning signal. On one occasion in fact when I kept on
grinding anyway the shaft jerked so hard it pulled itself out of my
hand & wrapped itself into a knot. I thought “oh-oh, so much for
that shaft” but after untwisting it worked just as before.

Mike Zagielski are you monitoring? What does it mean when the shaft
stutters and goes rhythmically jerk-jerk-jerk?

Hans Durstling
Moncton, Canada


An important tip here for loading any accessory into a #30 Jacobs

  1. You will notice that the chuck has three discrete indentations.

  2. When you load in a flex shaft accessory, make sure that you
    engage the chuck key into each one, tightening and rotating,
    tightening and rotating, until all three have been accessed in this

  3. Why? If you move from a very tiny accessory, such as a small
    drill bit and then to a larger width bur, if you only continue to
    load and tighten with one indentation with the chuck key, eventually,
    the rotation of the Jacobs chuck could spin off center.

  4. By tightening all three, you insure that you have equal pressure
    bearing down on the accessory at all times thereby extending the life
    of your handpiece and creating a very tight fit.

There is no need for this when you use a quick change hand piece of
course, only ones that contain a Jacobs chuck (the three pointy parts
of the handpiece). However, one thing to note about quick change.
After a time, mandrels which load a Moors abrasive disk or a 3M
Radial Bristle disk will work harden and wear down and the handpiece
jaws can loose their grip. Especially important for the minute size
tolerance of the actuating jaw and the mandrel.

My friend has a Swiss Techno X handpiece and was yelling that now
she had to purchase a third one, because the mandrels were slipping
in the jaw assembly. I looked at the mandrel and realized that the
shaft had worn down. I found a newer mandrel and swapped it for the
one she was using. She exclaimed happily, "you fixed my handpiece!"
No, just swapped the mandrel.

Sometimes it’s just the $.05 part and not the $145 one. LOL

Karen Christians

I would take the handpiece off the shaft and check if the female
coupling in the handpiece is bent so it doesn’t get a good connection
or has too much play with the male coupling on the shaft.

(Yeah. That’s the best way I can describe the connection so go ahead
and snicker. I sure did when I reread it.)

Rick Copeland
Silversmith and Lapidary Artisan
Rocky Mountain Wonders
Colorado Springs, Colorado

it seems to me that one possible cause of your flex shaft's
vibrating MAY be overloading it 

Nope, certainly not an overload situation. It was doing it while
under no load at all, as well as while under load. But if you read
the message I just sent, Rio contacted me to replace the shaft.
Customer service lady thought it might have a small kink in the

As an explanation of what I’m using it for, I carve wood and
reconstituted stone. Nothing as hard as natural stone, and I’m using
tiny little burs. I am however carving for hours at a time, which is
why I went for the TXH, rather than the lighter duty options. I’ve
used a little Dremel Multi-speed long enough to have an ear always
open for the motor, to back off at the first sign of stress. (My
Dremel has survived for almost 4 years…It’s a brave little
trooper. Not shot now, either, just wanted to upgrade.)

I would advise you to be careful- It sounds like you need to start
letting the tool do the work rather than forcing it. It’s not faster
in the long run, as you’ll lose money and time in repairing the
tool. And you’re lucky it didn’t take your hand off or smack you in
the face.

Lindsay Legler,
Dreaming Dragon Designs

Looks like I’ve got the issue solved: A VERY nice Customer Service
rep from Rio Grande called me today, and they are sending me a new
flexshaft. Seems they watch this list, and the part about the shaft
getting warm might indicate a small kink somewhere in the shaft
itself. Interestingly, a guy from Fordom e-mailed me too. So it
looks like my impulse to ask the question here was a good one.

Lindsay Legler
Dreaming Dragon Designs

I recently upgraded from a Dremel to a Foredom too. I had the same
problem at first but soon realised that it was due to the extra
torque of the Foredom and the fact that I wasn't used to it. 

This is not correct. A dremel vibrates much more than a Foredom
should. Why screw around asking us? Get in touch with your seller or
with Foredom.


Something else you can check. Sometimes, if the coupling of the inner
shaft to the motor shaft is placed wrong, the tabbed end that couples
to your handpiece can be either too far out of the sheath, or not
extending out far enough. In one case, the handpiece puts the shaft
into a compressed state, which not only isn’t so good for the
handpiece (can make some of them run hotter than usual, by loading
the bearings more), but can make the inner shaft buckle a bit within
the sheath as it runs, which can cause a vibration. If the tabbed
end seems to extend farther from the sheath than it needs to in order
to properly engage and drive the handpiece, check to see if it can
mount further up on the motor shaft.

If the inner flex shaft is mounted too close to the motor, and not
enough of the tabbed end engages the handpiece, then this too can
make it not run smoothly, especially if the tab jams into the end of
the handpiece without fully engaging the slotted coupling. The
instructions that came with your flex shaft should describe the
appropriate distance that the tabbed end should extend from the
sheath, or you can simply judge it by eye from looking at the
handpiece and seeing about how far it needs to extend. it’s not a
super critical measurement, but it does have to be in the right
general area for the shaft to run smoothly.


A dremel vibrates *much* more than a Foredom should. Why screw
around asking us? Get in touch with your seller or with Foredom. 

In my case, as I said it was due to the fact that I was not used to
the extra torque and it was a possibility that the same was the case
with the person who asked the question - but apparently not.

I only had a problem with it for a few minutes initially until I got
used to the foot control, and ever since then it has been as smooth
as silk.


Another solution may be to coat the inner cable with Vaseline to
quite the vibration.

Jeff Herman

That’s great advice for anyone who is running everything in
Foredom’s line except the TXH square drive shafts. They are fixed
length and not adjustable that way.

Thanks for taking the time to reply.

Rio’s sending me a new shaft anyway.

Lindsay Legler
Dreaming Dragon Designs