Changing the Brushes on a Festool Rotex 150 Sander

Frank Pellow

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Location
Toronto, Ontario, CANADA
Three days ago my Festool 150 Rotex E sander stopped working right in the middle of a job. I could not find anything wrong with it and I had no internet access at the job site, so I had to work for two days with an inferior sander (a Makita 5 inch random orbital).

Yesterday afternoon, I contacted Bob Marino and he suggested that it was probably due to the fact that the carbon on the brushes had worn down and that they would need to be replaced. I have never worked on motors and had no idea what brushing even looked like. Nowhere on any Festool manual, or at their web site, or on the three forums that I checked could I find a description of the brushes changing operation or even a picture of the brushes. There was one article entitled “Dual mode sander Rotex RO 150 E: Maintaining” at the Festool USA WEB site that mentioned brushes but gave no information about them.

I was in the middle of trying to figure out how to order brushes when I remembered that a small maintenance kit had come with the sander. So, I checked it and, sure enough, it contained a couple of small chunks of carbon with wires dangling from them. “These must be brushes”, I happily :) said to myself. Now, I had to take the sander apart and locate the worn brushes. I managed to do the job and the sander now works, but I sure would have liked some instructions.

I expect that I am not the only one who would be intimidated by the task of changing motor brushes, so I am showing just what I did. The good news is that the task is actually quite simple. The pictures below show the procedure.

(1) Remove the two screws at the end of the handle, then slide back the motor housing:

Changing 150 Rotex sander brushings -1 -remove screws then slide back motor housing.JPG

The two (very) small yellow arrows point to the locations of the screws.

(2) You can find one of the brushes on the top then, flipping the sander over, find the other on the bottom. Pull aside small clip/spring that holds a brush in place (pointed to by the small yellow arrow in the picture below), then pull the carbon out of the slot.

Changing 150 Rotex sander brushings -2 -extract carbon from under spring.JPG

(3) Pull the connecting wire out of the connection on the sander, in order to completely remove the brush:

Changing 150 Rotex sander brushings -3 -pull out wire .JPG

(4) Flip the sander over and remove the other brush.

(5) Locate your replacement brushes. Here is the parts bag with one new brush shown on top:

Changing 150 Rotex sander brushings -4 -one new brushing sitting on parts bag.JPG

And, here is a photo of a worn brush and a new brush side by side:

Changing 150 Rotex sander brushings -5 -old and new brushings side by side.JPG

(6) Holding aside the clip insert the carbon of one new brush into the slot. Then place the clip over the carbon in order to hold it in place (again see the small yellow arrow):

Changing 150 Rotex sander brushings -6 -hold aside spring and instert carbon from new brushing.JPG

(7) Attach the wire to the connector on the sander, replace the other brush in the same way, then re-install the motor housing.
 
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You might want to try a different brand to see if you can get some useful life out of it. My Ridgid just runs and runs.
Good joke Allen! :D

And, I doubt very much that you have run your Ridgid sander for as many hours as I have run my Festool Rotex.

Anyway, running is only one reason for selecting a sander. I grant you that it is a very important criteria but, once the sander is running, the other criteria come into play.
 
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Hey Frank, now you can say you have changed the brushes in a motor, I guess that makes you a motor mechanic :thumb:

It is a fairly straight forward thing to do, but I'm a bit surprised that Festool has no instructions on doing it, you should send them a note suggesting it.

BTW, if you ever get stuck with a tool and the brushes are worn out, and you don't have any replacement parts, and you really need to tool just for a short time more, you "Can" get a bit more life out of the brushes, usually.

Just cut a small shim or sorts out of some wood, and put it behind the spring, this will put more pressure on the spring and let the brushes contact.

I would not recommend doing this unless you "Have" to, as it is not exactly the best practice, but at 4 PM on a Sunday, when the job had to hit the road on a Monday morning, and you just need to do that last 10 minutes of sanding, it can be a life saver.

Cheers!
 
Are "Brushings" the same as brushes, or do they do double duty as some kind of "bushing/bearing" too?

How many hours (estimate) did you have on the 150 before failure, Frank? Just an estimate is fine. I know you've used it a lot, following some of your project threads. Any other signs of wear on the 150? Gears? Bearings?

Thanks.
 
Are "Brushings" the same as brushes, or do they do double duty as some kind of "bushing/bearing" too?
I guess that I got the term wrong. :eek: See, I said that I did not know much about motors. I will go back and alter the word in this thread's title.

How many hours (estimate) did you have on the 150 before failure, Frank? Just an estimate is fine. I know you've used it a lot, following some of your project threads. Any other signs of wear on the 150? Gears? Bearings?

Thanks.
As best I can figure it out, I have run the sander for somewhere between 300 and 500 hours (in the slightly less than three years that I have owned it).
 
Hey Frank, now you can say you have changed the brushes in a motor, I guess that makes you a motor mechanic :thumb:
There is no chance of that happening. :D

It is a fairly straight forward thing to do, but I'm a bit surprised that Festool has no instructions on doing it, you should send them a note suggesting it.
I was very surprised as well. :( have already suggested documentation to Bob Marino and will do so to Festool themselves.

BTW, if you ever get stuck with a tool and the brushes are worn out, and you don't have any replacement parts, and you really need to tool just for a short time more, you "Can" get a bit more life out of the brushes, usually.

Just cut a small shim or sorts out of some wood, and put it behind the spring, this will put more pressure on the spring and let the brushes contact.

I would not recommend doing this unless you "Have" to, as it is not exactly the best practice, but at 4 PM on a Sunday, when the job had to hit the road on a Monday morning, and you just need to do that last 10 minutes of sanding, it can be a life saver.

Cheers!
Yes, once I saw what brushes were and how they worked, I did think of that. Thank's for the confirmation that it would work.
 
Good tutorial on repairing Festool equipment, Frank.:thumb:

I am, however, surprised that you would have to do any internal work on such highly regarded (by some) equipment.:eek: My 1/4 sheet PC sander is 6 or 7 years old, and the only repair I have made to it is replacing the foam pad under the sandpaper. :dunno: ;)

Also, as pointed out above, those carbon slabs with the copper wire sticking out of one end are called a brushes. When in place, they are brushing the commutator on the armature of the motor rotor. ( Consider yourself educated.:D )

Jump to serious mode:
Festool must put soft carbon brushes in the sander to prevent damage to the armature. Otherwise, they would expect you to order a set, rather than including a set with the sander. (Clue, order another spare set.)
 
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