I’m baffled. I’ve had my Rotex 150 for about a year and still have not learned how to control this beast.
I am finish surfacing a small table top (20′ x 30″; hard maple). I will be sanding along as a normal, well behaved ROS should (PC ROS standard is my ideal) when suddenly it will take off as if possessed! It lurches right, left, forward, back and even “hops”. No matter the grit. I am operating in the “EX” mode; selector toward the back. I’ve set the speed at many levels, though “4” seems to be least troublesome. When I use the Porter Cable ROS all is fine, but progress is slower.
1. What causes this and what am I doing wrong?
2. Should I operate in the “ROT” mode rather than “EX”?
3. What speed is best for a surface similar to the one mentioned?
4. Should I sand with the disc flat, with the leading edge tipped down slightly or the trailing edge tipped down slightly?
A puzzled and frustrated Frosty
Replies
20' isn't too small a table ;) of course, I'm sure you meant to say 20"
Sounds like the EX setting isn't set dead even. The gears on this unit of course allow you to either choose ROTy or EXcentric (hence the name).
Rotary will really tear up the wood, don't use it where finesse is required.
The speed is more a dependency on your abilities to hold it flat and the grit used for the wood. Always sand with it flat, you'll experience many issues such as you've described (jumping, lurching, etc) if you tip it.
It takes a little bit of getting used to in order to keep it perfectly flat, but once you get the hang, you'll really enjoy how effective the unit is.
Cheers,
Thanks for the suggestion on keeping the disc flat. I was tipping in an attempt to minimize the heebie-jeebie movements. The unit will run smoothly on most of the 20 INCH project but when it encounts some sections or different grain types it starts to jump. I am sure the selector is fully engaged in EX but perhaps the "internal transfer" is incomplete. I guess I'll try calling Festool.Thanks again,Frosty
I finally have the issue resolved. The folks at Festool were remarkable in their insistance on resolving my problem 1. Brushes need to be well worn in; run the toool at least 10 hours to be sure. I left mine unattended (at their suggestion) with no problems or over heating.2. The key was don't use too much vac suction when sanding. I had my Festool vac at max. When I turned it down to minimum, the hopping, lunging problem went away and I still had no dust left on the workFrosty
Ah, I had completely forgotten about the first weekends experience. Glad to hear it settled down so to speak.
Also, failed to ask if you had a variable vacuum so that definetly increases resistance. I have a silver marker that I used to make little tick marks on the Vac where I need to set the unit to (own a CT33) to get the best results on my sanders.
Glad to hear it all worked out for you. You'll enjoy the unit much more now I'm sure :)
Cheers,
Michael
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