DF 700 Domino Joiner Quality Issue. How bad is bad enough?

[CCWoodcraft]

I was getting substandard alignment results from my DF 700 and I initially thought it was user error.  After looking into it I found that the horizontal axis of the plunge cut was off by >.1mm.  I sent the tool into Festool repair and they sent it back with the attached samples demonstrating the problem and no note.  Am I missing something?  I checked the tool and the problem is still there. 

My expectation is that this should be unacceptable for a professional level tool.  What am I missing?

Edit:  changed .01 to .1.  Bad maths.

 

[ChuckM]

Were the registration surfaces checked flat and free of debris? I'm assuming the arrows are pointing to the non-registration surfaces. If the arrows are pointing to the registration surfaces, also check that the pieces are uniform in thickness.

 

[CCWoodcraft]

Were the registration surfaces checked flat and free of debris? I'm assuming the arrows are pointing to the non-registration surfaces. If the arrows are pointing to the registration surfaces, also check that the pieces are uniform in thickness.

These are the samples that Festool made.

 

[Cheese]

I don’t consider a difference in planes of .004” to be significant considering it’s a hand-clamped, hand-held tool. Machine that same piece of wood in a steel vise on a Bridgeport, ya, then that .004” becomes an issue.

Just for fun, try clamping the 700 to the wood and see what you get.

 

[ChuckM]

[attachimg=2]

Were the registration surfaces checked flat and free of debris? I'm assuming the arrows are pointing to the non-registration surfaces. If the arrows are pointing to the registration surfaces, also check that the pieces are uniform in thickness.

These are the samples that Festool made.

My questions are still valid, regardless of who milled the mortises.

If the arrow points to the registration surface, what needs to be measured is the distance shown in red in the sketch.

 

[kevinculle]

Agree with Cheese, when you get significantly below 0.010"/0.25mm with woodworking tools and wood workpieces you are at the limit of repeatable results without taking extraordinary measures.

 

[Birdhunter]

I sometimes get slanted mortises with my 700, but never with my 500. My guess is that the dynamics of drilling into wood with a large bit torques the cutter into a climb. I find that a slower plunge lessens the slant effect. Not a mechanical engineer so this is just a guess.

 

[Cheese]

Not a mechanical engineer so this is just a guess.

With that answer…you could become an honorary ME.  [big grin]

 

[AlexThePalex]

I don't understand why people think tolerances of 0 are possible with a living, breathing material like wood. A result of > .1 mm is excellent already and not a reason to complain, or even suspect you have a faulty tool. Of course Festool send it back without doing anything to it.

 

[Birdhunter]

I graduated with an EE degree followed with a Masters in Systems Engineering. However, most of what I really needed to know, I learned on the job either from other people or from recovering from my mistakes.

My woodworking began long before the internet was even conceived and when television only had 3 grainy grayish channels. If the internet existed when I started with all its wonderful information, my craft would have been accelerated greatly.

 

[chrisrosenb]

I have been using the 500 Domino since they became available in the US. I have been using the 700 for many years. I have never checked if the mortises were perfectly parallel with edge. Because I have worked with wood, I see no reason to.
I converted .1 mm to an inch & it comes up as zero. I got out my digital caliper & set it to .1 mm. I my opinion Festool has done a great job with the Domino.

 

[semenza]

    .1mm seems that it should be accurate enough.  But "twisted" / non-parallel domino mortises can definitely be an issue even if they are not off by much. Especially since the mating mortises will be flipped in relation.

    I have had this be a problem but not with  .1mm .

  [member=78350]CCWoodcraft[/member] could you elaborate on the alignment issues? Is this just measurement, or are you having problems getting actual pieces to mate?

  Seth

 

[ChuckM]

Is 0.1mm -- about the thickness of an A4 size paper -- a lot? It depends on what the build or joinery is, and the tolerance of the individual woodworker.

If I built a cabinet out of plywood for my kitchen or shop, that wouldn't be a big deal. But for something that demands exactness, 0.1mm is too much for my taste:

[attachimg=1]
[attachimg=2]

 

[smorgasbord]

Nice! What kind of Domino jigging did you make/have to cut that?
And in pine? Was that a test?

 

[ChuckM]

It was a simple pine stand.

[attachimg=2]

The trick is a complementary stop block, and accurate miter cuts -- I used the Kapex. You can do it on the table saw like Tage Frid, but as he admitted, it's "very difficult to make."

[attachimg=1]

 

[smorgasbord]

The trick is a complementary stop block, and accurate miter cuts -- I used the Kapex. You can do it on the table saw like Tage Frid, but as he admitted, it's "very difficult to make."

I meant jigging for the Domino cuts into the angled ends.

 

[ChuckM]

No jig was used with the domino machine, just placement lines. To ensure consistency and dead-on marking, I made a cradle to mark the pencil lines.
[attachimg=1]

 

[Crazyraceguy]

I have done those, as sort of proof of concept and testing reality at the same time. The real challenge is actually pushing them together. It needs to happen all at once. I tested each pair separately to confirm before gluing and just went for it, assuming that if I did get it together dry, it would not come back apart.

 

[ChuckM]

For an easier assembly, mill the mortises before cutting the miters:

[attachimg=1]

Regardless of which approach is used, the clamping and checking should be the same:

[attachimg=2]

 

[CCWoodcraft]

[attachimg=2]

Were the registration surfaces checked flat and free of debris? I'm assuming the arrows are pointing to the non-registration surfaces. If the arrows are pointing to the registration surfaces, also check that the pieces are uniform in thickness.

These are the samples that Festool made.

My questions are still valid, regardless of who milled the mortises.

If the arrow points to the registration surface, what needs to be measured is the distance shown in red in the sketch.

I clamped it and registered off the base before I sent it in.  The issue is the horizontal axis of the cutter is out of alignment with the entire fence assemble including the base.  While the amount may not seem like much, if using exposed tenons the skew is definitely visible.  The skew can also be fixed by using a shim.  My thought is that the tool should be more accurate than this.  >1mm is actually quite a bit considering that it is over ~1cm.  This is really just bad QC.  The comments below saying working with wood doesn't need to be accurate are not relevant and aren't considering all of the uses of the tool.