Festool Domino mortise is not parallel to face when edge joining

[Ricky]

When edge joining using the Domino, mortise is not parallel to face of workpiece. result is the two workpiece edges are near flush on one side of mortise and then taper out of flush on other side of mortise.  have used this machine several months (edge Joining) and have had good results. This condition just started. Any suggestions

 

[peter halle]

Ricky,

First,  [welcome].  Others will come and give ideas, but the first on on my mind is, after using the domino for several months maybe your bit is dull?

 

[MarkF]

New one for me.  Is excess sawdust built up keeping the bit from swinging fully side to side?  Is the dust extraction pathway clear in the machine? 

 

[Brice Burrell]

[welcome] to the FOG Ricky!

I'm not sure if I understand your problem correct, but of parallel mortises are usually the result of the plunge rate being too fast or too slow. Check out this chart in Peter's reply #4.

 

[tigger]

Hi Ricky, welcome to FOG.

I will have to agree with Peter and Brice on this one. As the bit become dull, or blunt, it tends to "creep" up or down on your piece. It no longer has the sharpness to bite into the material on first contact. If you plunge too quickly, this result will be exaggerated.
I tried all sorts of adjusting to prevent this from happening, only to find that I needed to sharpen the bit.

Good luck

 

[MarkF]

Good stuff about the same issue discussed here over the previous ~2 years :
http://festoolownersgroup.com/festool-tool-problems/domino-mortices-not-horizontal-anyone-seen-this-beforei-still-love-the-thing!/?all

Looks like it could be a problem with the tool or a problem with how you use the tool or both.

 

[Ricky]

Thanks for all the responses.  The last response by MarkF and his link to similar condition was exactly the problem
I'm having. Whether its user caused or other condition I'm not sure. I just know that its worked perfectly up until now and i can't understand what's changed.  I have changed cutter sizes (some that have not been used but 2 or 3 times) and i get the same problem. My next step is to contact Festool.  Again, thanks for all suggestions and patience with technically challenged woodworker.

 

[Brice Burrell]

Ricky, I really do think this could be a case of plunge speed. Try slowing down the plunge rate first, if that doesn't work speed up. Check out this Domino mortise trouble shooting document.

 

[Ricky]

Thanks Brice, i've printed out the chart and will try different speeds.

 

[Michael Kellough]

Sometimes the fence doesn't camp down parallel to the base (it only clamps on one side). It isn't much of a problem if you're using multiple Dominos but if you use only one as in joining a small frame then the parts will be twisted. Where are the links to those discussions?

Is there a simple way to check parallelism of the fence to the machine?

The auxiliary jig Ron and others have made that basically extends the base out so you can register the work to the base should eliminate this particular issue but you only get one or two depths.

 

[bionicus]

When my Domino was doing this I found that the fence was gradually slipping/shifting under downward pressure. As a simple fix I removed clamping foot and used an emery stick to lightly scuff up the opposite vertical mating surface on the fence. I've also noticed that my fence exhibits a tiny bit of slop side-to-side when it's not clamped down, so now I always make sure to lift and lower it only from the left side before clamping at the desired height.