How do I tame my RO 125?

[EWTHeckman]

Since my RO 125 is new and I'm getting ready to do a lot of work with it, I've been practicing with some scrap pieces of wood. But I've been struggling with the RO trying to take off in all different directions on me. It'll be good through part of a stroke, and I'll be moving it as smoothly and evenly as possible, then it'll suddenly go off on some random tear, sometimes even trying to change direction several times a second. I eventually get the piece nice, but this is exhausting.

I have it hooked up to a CT 26, and this happens even with the suction turned all the way down. The piece of scrap I'm sanding is clamped down to an admittedly shaky surface, (a Stanley Workmate Pro) but I've pushed it up against a much more stable workbench with no change. It's 3/4" thick Poplar. This occurs in both rotary and random orbit modes. The paper I'm using is all Granat, grits ranging from 60 to 220. It also happened with both the hard pad and the stock (medium) pad. I've tried varying the pressure I'm using with no change. I've also tried varying the the speed between 3 and 6, again, it continues to happen.

I'm probably doing something wrong, but I can't figure it out. Suggestions?

 

[Brice Burrell]

Ed, it's a fine balancing act that have to learn.  Have you ever used a floor polisher/buffer?  The first few times you try using it, it takes you for a ride.  The more you try to force it to do what you want it to, the more it seems to fight back.  Then you figure it out and the thing just glides across the floor.  It's pretty much the same with the RO125.

The problem with the RO125 is the elongated body with the weight of the motor towards the back.  This is a lot different compared to a regular random orbit sander.  It's natural to inadvertently basis the RO125 towards the back, this throws the balance off and it can go crazy.  The difference between getting it right and getting it all wrong is almost inappreciable.  It's just something you have to figure out for yourself.       

 

[peter halle]

Ed,

Brice gave some great info and advice.  Just wanted to also remind you of the break in period.  Find a way to hang it up where it can't sand anything and then leave it for 4 to 8 hours running so that the brishes brek in.

Peter

 

[mouppe]

There is a learning curve that goes with the RO125.

I like to have one hand on the head and one hand towards the back in Rotex mode. You need to guide the sander and be in control of it, but not fight it (if that makes sense). In RO mode, one hand on the head usually suffices once you get the hang of it. You may want to start using it in Random orbit mode until you get a feel for the balance of the tool before going for it in Rotex mode.

Good luck- it is well worth persevering,

Richard.

 

[EWTHeckman]

You may want to start using it in RO mode until you get a feel for the balance of the tool before going for it in RO mode.

That's a little confusing. Could you clear it up?

Thanks for the advice everyone. I'll keep at it.

 

[EWTHeckman]

Brice gave some great info and advice.  Just wanted to also remind you of the break in period.  Find a way to hang it up where it can't sand anything and then leave it for 4 to 8 hours running so that the brishes brek in.

Is there a particular mode I should use?

 

[mouppe]

Edited my post.

 

[tbellemare]

In RO mode, one hand on the head usually suffices once you get the hang of it.

It just goes to show ya', different hand holds for different folks...

In RO mode, I use one hand where the hose connects. All I'm really trying to do is take the weight of the hose and cord out of the balance equation. When I do that, the Rotex sanders float as random orbit sanders. With almost no effort, I can "steer" them around the work piece using subtle angles as they do the work.

Tom

 

[NoBreyner]

When in the more aggressive rotex mode make sure you support it by the knob-like head firmly to help steady, add pressure, or guide the sander.  When in the aggressive mode as you found will go everywhere you don't want it to go.  It may help to look at video reviews of how others use their rotex sanders to get tips on how to use it.

The technique starts at the 2:10 mark.

Paul Marcel's rotex demo

 

[Sparktrician]

Brice made an excellent analogy regarding the floor buffer.  You just have to find that balance point for yourself.  Tom's comment about hand placement is dead on, too.  I have one hand on the head at the normal place, then put the other hand on the furthest position from that, on the end of the barrel where the hose and power cord connect.  That hand is used for ever-so-slight changes in height to find the balance and keep the sander balanced.  Once I find that point, it's relatively easy to keep it balanced using the hand at the end of the barrel.  Try it on some scraps until you get the feel for it. 

[smile]

 

[jmbfestool]

Once you get the feel  you can hold the sander pretty much any where and you can control it with no problem! 

but the easiest way I found is to hold to Rotex by the end holding the cord and hose together taking the weight from the rear and by just holding the rear you should have full control!  Then by placing your other hand at the front (head)  apply pressure and to give more control.

JMB

 

[greenMonster]

Is the "breaking in" common to the whole rotex lineup?

 

[Brice Burrell]

Is the "breaking in" common to the whole rotex lineup?

No, it's far more of an issue with Festool's smaller sanders, ETS125 and RTS/DTS400.

 

[zapdafish]

these are things that i discovered to help me control my rotex

1) crank the speed all the way up
2) make sure the dust collection is on turtle mode
3) don't exert downward pressure, just guide it where I want it to go.

 

[junk731]

Buy the RO150 then are those troubles disappear. I've had the RO125 for 3+ years, loved it in aggressive mode, tolerated it in the other mode. Recently bought the RO150 and found it as pleasing as the ETS150 to operate, no more fighting. I will soon be selling the RO125. Just my experience.

John

 

[EWTHeckman]

It seems that my RO 125 and I have come to something of an understanding.

I ran it on low for about 4 hours, then an hour at 2 and an hour at 3 to break it in.

When I tried to use it again, it seemed just as squirrelly as ever. But kept at it and figured out a few things.

First, I noticed that the vacuum hose kept getting hung up on the edge of my workbench. So I tried draping the hose and power cord over my shoulder. That really reduced the "random" trips in various directions.

I played around with the suction. I didn't see much difference between minimum and maximum, but I wound up at around 40% suction. I also played around with the speed of the sander itself. I eventually found that 4 seemed to be the best balance.

I also figured out a good grip for me. I have my left hand cradling the front of the knob-like portion, much like cradling a small fuzzy animal. Not much pressure at all. With my right hand I hold it right at the back with my thumb over the top, my index finger hooked around the back of the tool and the rest of my fingers underneath. When things were behaving well, I could even take my left hand off for a brief period.

Most importantly, I figured out to watch the pad in random orbit mode. If the pad wasn't spinning, or was spinning pretty slowly, then I had the right balance. If it started spinning faster, it was a warning that it was about to get squirrelly and I needed to adjust. I even figured out which way I needed to adjust based on the direction that pad was spinning.

Finally, there were still some specific areas on my practice boards where the sander would insist on getting squirrelly anyway. I'm still working out the cause for that. I suspect low spots and/or differences in the density of the wood. (Knots in the pine I practiced on didn't seem to make much difference.)

Now I just need to figure out how to do this without getting so tense. My back was pretty sore when I stopped last night.

Thanks for all your help, guys!  [thanks]

 

[woodguy7]

My RO 150 can be a bit un weildly at times.  One minute it goes fine then it just starts jumping all over the place.  I have noticed it especially bad when sanding wood narrower than the pad like 140mm & less.  I have tried every speed & suction rate combination but like you, found there is no difference.

It just seems to have a mind of its own !

 

[tbellemare]

The 150mm diameter pads can take full suction much better than their smaller brethren.

Tom

 

[Scott B.]

Here is my pretty well seasoned Ro125 doing a bit of material removal in Rotex mode at 60g with Granat. Speed is set at 6, extraction 1/2. Some of the material is as much as 1/8-3/16" thick. The piece is unclamped.

This is an iphone video with the phone leaning up against a box of nails, approximately 10 inches from the piece. Note the lack of vibration, the lack of dust and the sound of the jetstream.

Festool RO125 in Rotex Mode: One Hand Operation

 

[Jonhilgen]

I've felt that my Ro125 was always a bit unruly.  I purchased it used on the fog, so it had already been through its break in period.  I tend to usually ignore the speed setting on most of my tools, because faster is, well,faster right? 

So just yesterday I decided to finally play with the speed setting, and still it was unruly.  But I realized I was dialing it down in full increments (6 to 5, 5 to 4) then I tried to just dial it a little at a time and found a sweet spot.  Once I found it, it was easy to find again even when changing grits. 

My  [2cents]

Jon