RTS 400 Sander - Vibration Problem

Joined
Apr 2, 2010
Messages
14
Good Day:

I purchased the RTS 400 a couple months ago and used it only a handful of times.  There seems to be excessive vibration and the sander wants to "dance" all over the workpiece.  This is very annoying, especially for a sander that is supposed to be used one handed.  I have seen the posts about letting the sander "run-in" and was wondering if this is Festool's official recommendation.  Is there any other workarounds for this problem?

Thanks,

Michael

Victoria, BC
 
Hi if you have a local dealer pop it in and ask them to have a look and if there is anything wrong you can get it repaired replaced under warrantee.
 
CanadianCraftsman said:
I have seen the posts about letting the sander "run-in" and was wondering if this is Festool's official recommendation.

Yes, I believe it is.  

And, since you have already seen posts on the topic, you probably already know that it takes some 10 hours to completely break-in the brushes.  One idea was to tie a rope around the sander and suspend it from a ladder and let it run.
 
CanadianCraftsman said:
I purchased the RTS 400 a couple months ago and used it only a handful of times.  There seems to be excessive vibration and the sander wants to "dance" all over the workpiece.  This is very annoying, especially for a sander that is supposed to be used one handed.  I have seen the posts about letting the sander "run-in" and was wondering if this is Festool's official recommendation.  Is there any other workarounds for this problem?

Yes, the statement that some sanders need to be run-in/broken-in is official. Here is the relevant article from Festool USA's Support Knowledgebase:

Q: I recently purchased a Festool sander and it seems to experience fluctuations in power.

A: All Festool 120 volt power tools use brush-type universal motors with self-seating brushes. These brushes are serrated on the surface with narrow triangular grooves. The grooved texture of this surface needs to be worn down to the solid carbon substrate before the tool will reach peak performance. This is called the break in period. During this break-in period the brush takes on the same cylindrical shape that perfectly matches the curvature of the spinning armature, resulting in full contact. Some of our tools need to be run for as long as 10 hours before the brushes take on this shape and the motor develops full power. Your sander will be susceptible to power line fluctuations during this period and may not run at a constant speed. This difference in power is more noticeable in the tools with smaller motors such as the ES 125, DS 400and RS 400 sanders. A new small sander doesn?t seem to have as much power as one that has been run for a while. Brand new, these sanders develop less than half their rated power. Use these machines for at least a couple of hours before deciding that something is wrong. This also will free up the bearing seals and break in the rubber collars so that the whole mechanism develops more freedom of movement.


Forrest

 
This might be a dumb question, but are you using a vacuum, is it set to low speed, this sander will dance all over the place with vacuum set on high. I use this sander all the time to sand between coats when finishing.
David Werkheiser
 
Hi:

I contacted Festool and they mentioned it might help to run it in.  If this doesn't help I will send it to their repair center.

Thanks.
 
Michael, my apologies, I didn't see your original question since I was on vacation at the time.  There's about a 10 hour break-in period for most, if not all, of our sanders.  During this period the brushes are getting seated and the sander is not producing full power.  It's possible that's what is causing your results.  If it doesn't work to your complete satisfaction, please call back and we'll get it repaired to your satisfaction.

Thanks,
Shane
 
I have had the same issues with mine. Its not like any other palm sander I have owned. I put it down to three things. One, it has a boatload of power, two, the built in Fan in it creates its own suction, and three it has a very small footprint relative to a normal 1/4 sheet sander.

Like others have said, let it run in, if you are using a vac, put it on low. Running in does make a difference. I was skeptical at first as well. I still think it should be a 1/4 sheet sander even though the narrower width is somewhat useful.
 
Shane Holland said:
Michael, my apologies, I didn't see your original question since I was on vacation at the time.  There's about a 10 hour break-in period for most, if not all, of our sanders.  During this period the brushes are getting seated and the sander is not producing full power.  It's possible that's what is causing your results.  If it doesn't work to your complete satisfaction, please call back and we'll get it repaired to your satisfaction.

Thanks,
Shane

I'm experiencing the same issue with my two-week-old DTS 400. It dances around the surface, producing scratches and gouges. It's totally unusable. I'll reevaluate after the recommended break-in period. Thanks for the tip.

By the way, I unsuccessfully attempted to resolve this issue through Festool customer support. I tried submitting a message through the website, calling the support number, and directly emailing a contact at Festool. To date, I have been unable to speak with anyone. A significant motivation for assembling an all Festool shop was the reputation for quality support. Needless to say, I've been disappointed by the level of responsiveness from Festool. Is there some trick to getting a response?
 
Call again. [smile] Never had a problem getting through. Been a user since 2005.
 
I had been meaning to get back to this thread for some time...

I'd like to mention that Shane contacted me within an hour of my post, and I was contacted by the Festool service department first thing the following morning. Thanks Shane!

The tech basically echoed Shane's earlier advice about the 10 hour break-in period, although he felt that the amount of vibration I was experiencing was more than could be accounted for by poor brush contact. So, I ran the sander for a bit and reevaluated. There was a small but noticeable improvement. I also tried operating the sander without suction, which I hadn't tried before (it's a Festool!). This eliminated all vibration.

My conclusion is that the sander is simply very sensitive to suction. The downward pressure creates too much friction for the low mass of sander. The suction relief channels in the sander pad are not blocked, so I don't see any way that this could be the result of a unit defect, but I'd love to be proved wrong. I can operate the sander at maximum speed and low suction with acceptable results. And now I know that the sander runs smoothly at any speed without suction. I can live with this minor disappointment. I'm planning to fabricate a suction limiter, which should resolve the issue.

Still, if anyone has an RTS 400 that hums along at low speed with suction, I'd love to know about it.
 
Mine will if I have very fine paper in it 220 or so and I put no pressure on it at all. I have been using it a lot lately to sand down a ceiling. I was using 80 grit, low suction and had no issues except because of the shape (not square) its very sensitive to pressure being applied unevenly and it causes it to hop. Again, this thing, in a 1/4 sheet version would be the cats butt..
 
Chas said:
Mine will if I have very fine paper in it 220 or so and I put no pressure on it at all. I have been using it a lot lately to sand down a ceiling. I was using 80 grit, low suction and had no issues except because of the shape (not square) its very sensitive to pressure being applied unevenly and it causes it to hop. Again, this thing, in a 1/4 sheet version would be the cats butt..

What up with this?  Is this something like saying something is bad, when you really mean that it's good?  [unsure]
 
Are you refering to the Cat's behind comment? Cat's behind here means really good so what I was saying is that it is good but if it came in 1/4 sheet size, it would be great!

 
Hmmm.  That is surprising to me.  Usually an expression that refers to either a person's or animal's backside is meant to be derogatory -- as in a "horse's patoot."  Now, as to the "Bee's Knees,"  well, that one really has nothing to do with any part of a bee at all.  [smile]
 
I own one, I found that the dance was entirely caused by having the suction set too high. I never tracked break in hours, but I do find the problem if I ever have one, can be alleviated by lowering suction. On a side note, with the suction decreased, there is a bit more build-up on the paper, A rubber stick is a great thing to have.
 
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