RO 90 Hot

[JuliMor]

I just started using the RO 90 today.  After about 5 minutes I noticed it getting hot.  It was hottest near the dust port.  I'm switching back and forth between the RO 90 and RO 125, as needed.  The RO 125 runs cool, with no noticeable heat build up.  The RO 90 actually feels hot, almost uncomfortable.

Is this normal?  I know heat breaks down certain tool components and I'm worried there may be something wrong with this particular tool.

 

[Administrator_JSVN]

Julie,

Some people have reported their RO 90 running hot when they first get it. If you search the forum, you'll likely find a few discussions about it. It's nothing that should harm the tool. The RO 90 actually has electronics that will shut it off in an overheating scenario. It's likely the heat is there from the brushes getting broken in against the armature and it will go away after 8-10 hours of use.

Shane

 

[peter halle]

To add to what Shane said, The motor is actually at the rear of the tool where you are feeling the heat.

Peter

 

[JuliMor]

Thanks guys!  It will probably get that 8-10 hour break in over the next few days.

BTW, I'm really liking the RO90, after only an hour or so of use.  I'm sanding off stain and varnish on kitchen cabinet face frames.  Every pound counts when you're working vertically.  I can feel the weight difference between the 90 & 125.  And I'm really impressed with how quickly the finish comes off with the Deltex pad on. 

Thanks for the quick response!

 

[skids]

There are vents on the housing that depending on how you hold the tool may get blocked, which may (or may not) add a little heat to that sander. I would defer to Shane and Peter on that theory..I know I tend to hold my RO125 form the rear and block the vent at times. Never noticed abnormal temps..Quite honestly if I did I would still consider it normal since the way the Rotexes operate is pretty aggressive.

I often just dare my Festools to break on me, I don't care if my tools get scratched or pushed to the brink, they are tools so I consider that normal. In the case of all my festool stuff, it just seems to be built so tough it's never going to be an issue. And if it is, they have a  three year warranty. Like Festool drills, and Shane mentioned, there is circuitry to protect from over heating, with the drills it's protection from over driving.

May just be break in period for yours, or how you are holding it, or just the way that little rascally sander operates.  [wink]

 

[JuliMor]

The sander has seen a lot of action.  I know when I first started using it, it was running pretty hot, almost uncomfortably so.  I don't notice that anymore.  It is warmer than the RO 125 but no more so than my Bosch ROS.

 

[ccarrolladams]

Most of us break-in our new Festool sanders by hanging them and letting the motor run for up to 8 hours.

Also, the suggested way to use the RO 90 DX is to keep it steady with one hand on the knob and use the other hand not on the tool but on the hose and Plug-It just to take the weight off those so the sander does not tip. This way even if the sander were to heat, your hand is not near the heat.