RTS 400 - control issue

[Len R]

Tried my RTS 400 for the first time today, just to do some light sanding on a picture frame.  It was too jumpy to control, bouncing all over.  I tried reducing the speed, and then reduced the CT vacuum all the way, with no change.  After a while, I gave up and switched to my ETS125, which was smooth as silk.  My ETS 150/3 occasionally jumps around, but if I pay attention I can control it.  The RTS 400 felt like my RO 90 in aggressive mode.  I couldn't use it.  Is this jumpiness normal for the RTS 400? It was really bouncing around. BTW I was using Festool sandpaper, 220. 

Thanks,

Len

 

[rizzoa13]

Seems like your doing the right things to make it manageable. I'd only suggest that you hold it very lightly if it wants to chatter. Holding it firmly seems to make it want to catch even more. Good luck!

 

[AlexThePalex]

The RTS 400 felt like my RO 90 in aggressive mode.  I couldn't use it.  Is this jumpiness normal for the RTS 400? It was really bouncing around. BTW I was using Festool sandpaper, 220. 

This is normal for a brand new RTS400. You need to break it in first, it needs 8 hours of use to get into shape to perform normally.

The problem with a new RTS is that the brushes are square and are therefor not properly seated on the round armature. They need to wear a bit to adjust to the shape. Only then will you be able to use the full power of the RTS and it will be smooth as silk.

 

[Slartibartfass]

Alex, you certainly know your Festools. Thx for sharing the info. Malte

 

[vteknical]

Try it with no dust extraction using just the supplied bag. 

 

[AlexThePalex]

Forgot to mention that an often used trick by people here on the forum is to hang the sander by a rope and just let it run for 8 hours all by itself. Spares you the agony of doing it by hand. The sander can take the long run without problems.

 

[Len R]

Thanks Alex.  I recall reading a thread a few months ago on the "break in" theory.  Some knowledgeable folks disagreed that any break in is necessary.  I am also doubtful about it because I bought my ETS125 at the same time as the RTS400.  The ETS125 was silky smooth from minute one.  Why would the RTS need 8 hours of break in and the ETS125 need none at all?

Regards,

Len

 

[elfick]

I just finished a project with a RO150, RO90, and a DTS. The DTS was by far the hardest to control. I didn't have any problem running the RO150 one handed but the DTS kept me on my toes. It only has a couple hours on it so if it mellows out eventually I'll be stoked.

 

[Pixel]

The RTS 400 felt like my RO 90 in aggressive mode.  I couldn't use it.  Is this jumpiness normal for the RTS 400? It was really bouncing around. BTW I was using Festool sandpaper, 220. 

This is normal for a brand new RTS400. You need to break it in first, it needs 8 hours of use to get into shape to perform normally.

The problem with a new RTS is that the brushes are square and are therefor not properly seated on the round armature. They need to wear a bit to adjust to the shape. Only then will you be able to use the full power of the RTS and it will be smooth as silk.

I have never heard such stuff as your comment, the brushes do nothing to the action of the sander, the action of the sander is controlled by the cams.

 

[AlexThePalex]

I have never heard such crap as your comment, the brushed do nothing to the action of the sander, the action of the sander is controlled by the cams.

Dude, this was the official explanation we got from a Festool employee. The break in period on these small sanders is very real. 

 

[AlexThePalex]

As I said, this was an official Festool answer. Placed on the FAQ of their website and then copied here on the forum by a former moderator. The post can be read here:

http://festoolownersgroup.com/festool-tools-accessories/%27dst-400%27/msg15579/#msg15579

If you know it better than Festool, fine.

 

[rizzoa13]

I think id believe the explanation that the manufacturer gives over someone else (who didn't give an alternative answer) any day.

 

[Pixel]

I think id believe the explanation that the manufacturer gives over someone else (who didn't give an alternative answer) any day.

Nothing to do with the brushes, the leading edges towards the point of the sander means the edges of the paper are digging in as you move the sander, on narrow strips of wood this will cause it to be somewhat uncontrollable, using a square sander would make it a bit better but if the wood is narrower than the sander then use an eccentric sander or do it by hand.
The reason Festool make as many variations of sanders as they do is to overcome every aspect of sanding so choosing the right one is essential.

 

[elfick]

As I said, this was an official Festool answer. Placed on the FAQ of their website and then copied here on the forum by a former moderator. The post can be read here:

http://festoolownersgroup.com/festool-tools-accessories/%27dst-400%27/msg15579/#msg15579

If you know it better than Festool, fine.

 

[orm8426]

As I said, this was an official Festool answer. Placed on the FAQ of their website and then copied here on the forum by a former moderator. The post can be read here:

http://festoolownersgroup.com/festool-tools-accessories/%27dst-400%27/msg15579/#msg15579

If you know it better than Festool, fine.

 

[AlexThePalex]

Alex,
The link you posted discusses a lack of power, not a difficulty of control...
"This difference in power is more noticeable in the tools with smaller motors such as the ES 125, DS 400 and 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. "

It's the same issue, one thing leads to another. If your sander lacks power it will bind with the material instead of sanding it, making it jumpy and difficult to control. Once these sanders have full power they are very smooth.

Am I the only one who thinks, given the price point of Festool, these sanders should be "run in" at the factory and be ready for immediate use at 100% performance straight out of the box?

You are definitely not the only one. Even a cheap sander should run 100% right from the start. I don't understand Festool's choice to do it this way. You won't believe the number of posts we read about this issue here on the FOG, and very often people are so dissatisfied with the sander they would return it right away if we wouldn't tell them otherwise.

 

 

[tiralie]

Is this jumpiness normal for the RTS 400? It was really bouncing around.

Len:
When I first got my RTS 400, I used it to sand the curved edge of a 1/4" MDF template I was preparing to use with a router. It was very "jumpy" at first but it soon settled down. I agree that sanding the edge of a thin board added to my problems but I really think the vacuum hose pulls the back of the sander off balance and creates the jumps or "wheelies" the back end.
I have used it frequently since I first got it and can make it "jump" when two sides of the sander pad touch the vertical sides of a drawer when going into the corners.
I really like the RTS and have used it a lot. Brillant little sander. If I am using it for any length of time, I will sling the power cord and vacuum hose over my shoulder which seems to neutralize the "wheelie" affect from the hose and cord.
I have a DTS, and it didn't jump at all when I first used it and presumably it has the same brushes and motor. The Delta shape probably just works better with the tall motor housing etc.

Alex,
The link you posted discusses a lack of power, not a difficulty of control...
"This difference in power is more noticeable in the tools with smaller motors such as the ES 125, DS 400 and 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. "

It's the same issue, one thing leads to another. If your sander lacks power it will bind with the material instead of sanding it, making it jumpy and difficult to control. Once these sanders have full power they are very smooth.

Lacking power seems to be a logical explanation but I am not sure that is the problem.
I don't know anything about electrical motors or Festool tool motors for that matter, so I will defer to those who do.

Lets assume as Len has stated that you change the power setting from 1 to 6 with no difference in (perceived or actual) "jumpiness". That would remove the aspect of lack of power as the issue, wouldn't it?

Tim

 

[AlexThePalex]

Lets assume as Len has stated that you change the power setting from 1 to 6 with no difference in (perceived or actual) "jumpiness". That would remove the aspect of lack of power as the issue, wouldn't it?

If it's already lacking power at 6 then it will also lack power at 1.

I went through all this myself with a brand new DTS400. I already had the DS400 and the RTS400 (bought both used), so I knew exactly how these sanders should behave. When I used the new DTS for the first time I was severely disappointed with it because it was utterly weak and tame. I didn't understand it. If I dialed it down below 3 I could make it come to a full stop with the slightest touch. On higher settings it would behave erratically, jump around and stutter. I knew something was not right and was afraid I had to RMA it. But then I searched on the FOG for this issue and found out about the brushes and break in period.

So I sat through the break in period for the next two weeks, using it occasionally. Until I finally noticed the sander came to life. It finally got power and behaved like it should.

Take my words or don't take them. This issue has come up many, many times already. Do a search on the FOG for "break in" or "DTS brushes" and you will find many threads about this subject.

If you have some new insight to add why this might happen, I'll be glad to hear it,.

 

[SS Teach]

I've had an RTS 400 for 3 years. It has been smooth as silk from day one when I pulled it out of the systainer.

 

[tiralie]

On higher settings it would behave erratically, jump around and stutter. 

Ok, let me say I am not doubting you but I am curious as to why this lack of power would translate into a jumpy stuttering machine.

Take my words or don't take them. This issue has come up many, many times already. Do a search on the FOG for "break in" or "DTS brushes" and you will find many threads about this subject.

I read the link in your post earlier (Thank you, I had never read this before) which has lead to the questions I have as to why lack of power creates a mechanical(?) problem.
As noted earlier I have no understanding of how these sanders work so some explanation would help.
Tim