ETS 150 sander going off course due to the "jagging" phenomenon

[FenceFurniture]

This forum member was banned due to evidence that he was attempting to promote a brand of abrasives that he imports and sells in Australia. The issues that he states about his sander were to help him substantiate why people should buy the other brand of abrasives. Our forum rules state that members must disclose their affiliation with product manufacturers to maintain transparency and help readers understand bias.

Does anyone else get what I call "jagging" when using their ETS 150 sander?

Mine is a 3mm stroke, but I suspect that the stroke has nothing to do with it, and that it has everything to do with the abrasives that are being used.

What I mean by jagging is that the sander pushes and pulls away from the direction in which I'm sanding. It's a bit like trying to pull the sander through a field of rare earth magnets. It causes the sander to miss spots and sometimes can be quite a large deviation - yesterday I had a couple of occurrences sanding a 4½" wide board where the sander suddenly went in an arc that missed 2" of the width of the board. It doesn't happen every now and then - it's quite constant but to constantly varying degrees.

I only notice this with 17 hole discs, and have found that one brand does this more than one other brand, and yet another brand of paper does it far less. When I'm using papers that are covered in micro-holes it's a smooth as silk with no jagging whatsoever (thus indicating that there is clearly nothing wrong with the sander itself). It's also as smooth as silk when I'm using abrasives with no holes at all (like Platin 2).

I have tried turning the vac power down, RIGHT down, and then finally completely off - doesn't make an iota of difference.

I find this jagging adds considerable fatigue during a long sanding session due to constantly fighting to keep the sander on track.

 

[AlexThePalex]

This behaviour you describe is normal for any kind of random orbit sander. You have a round pad spinning on a flat surface, it will always try to go its own way the moment you lose control, even for a second. You have to hold tight onto it to keep it in line. And if you miss a spot, just move the sander back to it, should be no problem. A sander is not like a router where one deviation could screw up your work.

I'd like to add that I notice you were using the 5'' sander on a  4½" wide board, problems like this can occur when your pad is wider than the piece you are sanding. When the pad goes over the edge, which is inevitable when your piece is too small for the pad, the pad can cup due to it's flexibility and grip the edge, which pulls your sander off course. The solution to minimise this is to use the hard pad for your sander instead of the standard soft pad.

 

[FenceFurniture]

Thanks for your reply Alex. I'm actually using a 6" pad (ETS 150), but of course that only adds to your argument [big grin]

I should have specified that I am actually using a hard pad.

Hear what you say, but if that was the case it surely wouldn't matter what disc brand or hole pattern was on there, it would do the same. But that's not the case - microholes - smooth as silk, 17 holes - a rough ride (except for one brand in grits 80 to 220 so far - at 320 grit this brand is also doing it). There's a bit of a complicated explanation for that brand which I won't worry about at the moment.

Also, nobody over here (Oz) seems to get this phenomenon. Are you saying you get it?

I'm in the middle of testing/comparing four brands over 6 grits. I have literally sanding over four miles in the last few days. 

 

[oldie]

Interesting post.  Kudos for sanding over 4 miles of wood in a few days with a ‘fine-finish’ sander – reckon I’d be experiencing more than “considerable fatigue” regardless of what sander I was using.  [embarassed]
What Alex posted, of course, correct.  Subsequently my thoughts were along the lines of:
1/  is the sander running correctly - at max’ speed? 
2/  appropriate suction power should help, not hinder, the process – especially where pad over-lapping the edges of board.  What extractor are you using? 
2/  how ‘rough’ is the surface you’re sanding, and, how much does the ‘roughness’ vary?  Does the wood surface have much in the way of tiny ‘whiskers?’ 
3/  you’ve found an abrasive that works for your task – just curious why even bother with others? 
4/  is it possible that a belt sander might have been better in the circumstances? 
5/  does the sander ‘float’ on the surface when sanding – or are you exerting too much down pressure? 
6/  is it possible the moisture content of wood variable enough to cause a problem?

Fwiw, reason I’m interested in your experience is, that what’s going on for you has relevance whether sanding 4 feet or a lot more. 
Looking forward to input from others and yourself. 
Richard.

 

[FenceFurniture]

1/  is the sander running correctly - at max’ speed?  Speed set to just under 5 (out of 6)
2/  appropriate suction power should help, not hinder, the process – especially where pad over-lapping the edges of board.  What extractor are you using?  CTM 26 AC hooked up to a 60mm dia ducted system with a 36mm hose going into that. The suction is FIERCE.
2/  how ‘rough’ is the surface you’re sanding, and, how much does the ‘roughness’ vary?  Does the wood surface have much in the way of tiny ‘whiskers?’  Happens on virtually all timbers I have sanded as I recall. During this testing I started at 80g and tested 5 papers there. Now I'm working my way up through the grits 120 (4 papers), 180 (4 papers), 220 (3 papers), and am 2/3 the way through 320g (4 papers)
3/  you’ve found an abrasive that works for your task – just curious why even bother with others?  Because I'm testing for other people's benefit, and also to be able to quantify what I've been saying about my abrasives of choice for the last couple of years.
4/  is it possible that a belt sander might have been better in the circumstances?  Not relevant - trying to find the best 150mm abrasives going around
5/  does the sander ‘float’ on the surface when sanding – or are you exerting too much down pressure?  With the abrasives I normally use, the sander floats across the surface beautifully while doing the job - smooth as silk. I'm exerting the same pressure as constantly as i can on all the abrasives (for the consistent results that I need for the testing). I measured the pressure as best i can and it's about 9kg plus sander weight - moderate force.
6/  is it possible the moisture content of wood variable enough to cause a problem?

Fwiw, reason I’m interested in your experience is, that what’s going on for you has relevance whether sanding 4 feet or a lot more. 
Looking forward to input from others and yourself. 
Richard.

Cheers Richard. The timber is an old Eucalyptus fence post (20 years old in the ground???) that has been jointed and thicknessed down to new timber. Pretty damned hard, especially by Euro or USA standards, pretty run of the mill here.

I turned the vac down, and then down and then to minimum, and then actually disconnected the hose altogether, and it didn't make a blind bit of difference to the jagging - I tested 3 or 4 papers for this - results as per usual.

It doesn't matter even if there is no force on the sander whatsoever. I tried it just idling on the spot holding the tip of the handle with just fingertips. The bad news abrasive caused the sander to bob around on the spot (probably the random orbital action) and the smoothest running paper was noticeably more stable.

Oh yeah, I'm up to 8.37 kilometres now. [big grin] [crying]

 

[semenza]

1/  is the sander running correctly - at max’ speed?  Speed set to just under 5 (out of 6)
2/  appropriate suction power should help, not hinder, the process – especially where pad over-lapping the edges of board.  What extractor are you using?  CTM 26 AC hooked up to a 60mm dia ducted system with a 36mm hose going into that. The suction is FIERCE.
2/  how ‘rough’ is the surface you’re sanding, and, how much does the ‘roughness’ vary?  Does the wood surface have much in the way of tiny ‘whiskers?’  Happens on virtually all timbers I have sanded as I recall. During this testing I started at 80g and tested 5 papers there. Now I'm working my way up through the grits 120 (4 papers), 180 (4 papers), 220 (3 papers), and am 2/3 the way through 320g (4 papers)
3/  you’ve found an abrasive that works for your task – just curious why even bother with others?  Because I'm testing for other people's benefit, and also to be able to quantify what I've been saying about my abrasives of choice for the last couple of years.
4/  is it possible that a belt sander might have been better in the circumstances?  Not relevant - trying to find the best 150mm abrasives going around
5/  does the sander ‘float’ on the surface when sanding – or are you exerting too much down pressure?  With the abrasives I normally use, the sander floats across the surface beautifully while doing the job - smooth as silk. I'm exerting the same pressure as constantly as i can on all the abrasives (for the consistent results that I need for the testing). I measured the pressure as best i can and it's about 9kg plus sander weight - moderate force.
6/  is it possible the moisture content of wood variable enough to cause a problem?

Fwiw, reason I’m interested in your experience is, that what’s going on for you has relevance whether sanding 4 feet or a lot more. 
Looking forward to input from others and yourself. 
Richard.

Cheers Richard. The timber is an old Eucalyptus fence post (20 years old in the ground???) that has been jointed and thicknessed down to new timber. Pretty damned hard, especially by Euro or USA standards, pretty run of the mill here.

I turned the vac down, and then down and then to minimum, and then actually disconnected the hose altogether, and it didn't make a blind bit of difference to the jagging - I tested 3 or 4 papers for this - results as per usual.

It doesn't matter even if there is no force on the sander whatsoever. I tried it just idling on the spot holding the tip of the handle with just fingertips. The bad news abrasive caused the sander to bob around on the spot (probably the random orbital action) and the smoothest running paper was noticeably more stable.

Oh yeah, I'm up to 8.37 kilometres now. [big grin] [crying]

Hi,

  Welcome to the forum !  [smile]

  I find that I get this sander behavior with a random orbit when the surface has undulations. Causing the sander to grab when part of the pad is on a slightly high spot. The other causes are too much suction or too much pressure, but you have ruled those out.  Do you have a soft or super soft pad to try on the sander? I be curious if that would reduce the problem compared to the hard pad.  Have you tested it on a large surface that is wider than the pad?

Seth

 

[FenceFurniture]

Yes I do have those pads Seth, and can give them a spin. My forecast is that it will be almost, if not completely identical.

Strange how the microholes discs are as smooth as silk with the hard pad under all circumstances (vac on full, vac not connected, all grits). Speed of sander makes little to no difference either. It does reduce the ferocity of the jagging, but it's still well and truly there, even on speed 1.

Just for reference, the board is no longer flat after over 8 kms of sanding, but it happens on flat boards just the same as non-flat.

 

[roblg3]

I second the idea of the boards being not flat.  I have had very similar experiences and it took me a while to figure out it did that when it grabbed extra hard on a high spot.

 

[Administrator_JSVN]

The process of determining the issue is a process of elimination. Remove variables. Sounds like you've already ruled out dust extraction and suction as a potential cause. Sand something else that you know is completely flat and see if you have the same problem. Try a different abrasive, try a different pad if you have more than one since the pad could be warped or delaminated. If, after ruling all of these variables out and you are left only with the sander, then you know it must be a problem with your sander. If that's the case, contact your local Festool offices for warranty repair.

 

[FenceFurniture]

I only notice this with 17 hole discs, and have found that one brand does this more than one other brand, and yet another brand of paper does it far less. When I'm using papers that are covered in micro-holes it's a smooth as silk with no jagging whatsoever (thus indicating that there is clearly nothing wrong with the sander itself). It's also as smooth as silk when I'm using abrasives with no holes at all (like Platin 2).

Hi Shane

I have definitely ruled out any problem with the sander. It's only 17 hole discs that it occurs with. Discs with hundreds of microholes are very smooth in operation.

I've been noticing it over the last couple of years on pretty much everything i sand with 17 hole discs, and at the same time noticing that I doesn't happen with microhole discs. It's just come right to the fore during this testing which involves quite a few 17 hole discs, and of course I am being particularly observant of all characteristics during a testing comparison. It hasn't really been an issue in the past because i tend to use the microhole discs as a matter of course.

Will sand a very wide board in the next hour or so to see what happens, but my recollection is that the behaviour is the same.

 

[Administrator_JSVN]

The discs "with microholes" are Platin, I assume. That's our abrasives that are 500-4000 grit. They have a padded backing, making them more "squishy". So, you're negating any lack of uniformity in the pad.

I would recommend that you try one of your other pads. And, since sometimes people use the word pad to mean different things, a pad is the white foam thing on the bottom of the sander that you attach the abrasive disc to. If there are irregularities in the pad, you could experience weird behavior. That would be my next step.

Full speed (6) on the sander, half suction on the dust extractor.

Photo of Platin:

 

[FenceFurniture]

Ok, have done a few tests.

The 17 hole disc was 220 grit Rubin 2 (brand new out of the drawer), and what I refer to as the microhole disc has a couple of hundred or more holes that are 1½ to 2 millimetres in diameter.  it  The back of it is only very marginally softer than the Rubin back.

I sanded four different pieces, with and without dust extraction (either full suction or off). The DE made no difference at all.

Using a hard pad (understand what you define as a "pad" - that's my definition too).

Sander speed just less than 5.

Results are:
The original piece of hardwood (4½" wide so the sander overlaps the edges by 3/4" each side) - same face as the previous 8 kilometres
microhole disc - smooth ride (with and without DE)
17 hole disc - moderately rough ride (with and without DE)

That piece of timber does not have lumps and bumps, just a bit of cupping from all the previous sanding.

The reverse side of the hardwood - straight out of the thicknesser - flat as a tack
microhole disc - smooth ride (with and without DE)
17 hole disc - much rougher ride (in fact quite difficult to control the sander - seriously) (with and without DE)

Piece of softwood (Mango root) - straight out of the thicknesser - 10" wide
microhole disc - smooth ride (with and without DE)
17 hole disc - moderately rough ride (with and without DE)

10" wide piece of MDF
microhole disc - smooth ride (with and without DE)
17 hole disc - moderately rough ride (with and without DE)

As I slowed the speed of the sander down the ride did become a bit smoother, but was still not the same as the microhole discs where the speed made no difference - smooth all the way.

Changing to the "Soft" pad and using the same discs and timber pieces:
This diminished the roughness of the ride quite a bit. I will only show results for the 17 hole disc (microhole was tested - all smooth).
The 8km face of hardwood - noticeable, but not too bad
The flat face of the hardwood - quite noticeable
Softwood - only barely noticeable because i was looking for it - nothing to complain about
MDF- only barely noticeable because i was looking for it - nothing to complain about

So, after that:

• I know that the hard pad exacerbates the rough ride quite significantly. Yesterday I changed to a brand new hard pad - identical rough ride.
• Hardwood exacerbates the rough ride
• Dead flat hardwood results in an even rougher ride (hard to control the sander - came close to out of control at one point)
• Dust extraction power makes no difference at all

 

[semenza]

Not sure what to tell you. Something funny going on with it. Maybe time to have it checked out. I use both the  ETS150/5 and the ETS150 /3 with a whole variety of Festool 17 hole abrasives (Platin also), and I only get that problem if there is something obvious such as too much suction, pushing down on the sander, or uneven surface.  ???

Seth

 

[FenceFurniture]

Heh heh, join the queue of people who can't figure it out Seth.

I'll get hold of a couple of mates who have an ETS 150 and get them to come around with the sander. Will keep the board in reserve. Now THAT will be interesting. I'll also get them to operate my sander on said board, just to make sure I'm not dreaming  [blink]

What's the bet that their sanders suddenly start misbehaving?  [jawdrop]

 

[Gary in Texas]

Heh heh, join the queue of people who can't figure it out Seth.

I'll get hold of a couple of mates who have an ETS 150 and get them to come around with the sander. Will keep the board in reserve. Now THAT will be interesting. I'll also get them to operate my sander on said board, just to make sure I'm not dreaming  [blink]

What's the bet that their sanders suddenly start misbehaving?  [jawdrop]

I will go with......they will experience the same problem, if equally equipped with same grade of sand paper.......

I've experienced the same thing a few times in past, not with my ETS125, and concluded it was the wood property/grain pattern/ or cosmic event....

 

[FenceFurniture]

It's a very straight grained, ordinary piece with no fiddleback (which is why it was selected for the main abrasives comparison test - this jagging is a sideshow that I'm trying to solve).

Will photograph later, when I'm finished the 1500 grit tests.

 

[Roseland]

Is it possible that the pad isn't flat?  If the sander was stored on it's side it could have a small lip on the edge, which could  cause erratic behaviour.

Andrew

 

[FenceFurniture]

Is it possible that the pad isn't flat?  If the sander was stored on it's side it could have a small lip on the edge, which could  cause erratic behaviour.
Andrew

I changed it to a brand new hard pad Andrew - guess what the difference was.........well I'm still here looking for answers......

 

[FenceFurniture]

Might just have to open this up as a competition - whoever can supply the answer gets, hmmmmm, lemme see.....

I know! They can have my supply of 17 hole discs! ROFL  [big grin]

 

[semenza]

Baremag nailed it ..... it is a cosmic event.  [blink] 

          OR

It is because the sanders spin in the opposite direction in Australia. So you have to turn the board around facing the opposite direction as well. You knew that , right  [huh]  [tongue]

Seth