Dominos Too Tight

[Monju123]

When I drill a 6mm Domino mortise on the 1st position, I can not even hammer the Domino in.  The width of the mortise is .719 in, the width of the Domino itself is .79". Any suggestions? The height of the mortice is fine. I have tried the microwave solution with no success. Where can I find the specs on tennon  and mortise sizes? Is the .719 I get too small? This Domino is from a newly opened bag.

 

[bkharman]

Is the cutter old?  That doesn't look right. Is that board Pine?

 

[Monju123]

Wood is maple. Cutter is old, but not heavily used. The height of the mortice is fine, which in my mind rules out the bit. I am wondering if the bit is oscillating widely enough.

 

[semenza]

    I agree that it doesn't look right. The sides of the mortise don't look even to me, but might just be the perspective of the picture?

    Is the pencil line traced around the domino? If so that sure looks like the mortise is waaaay under sized.

    Try a test with a medium or wide mortise setting to see what happens.

Seth

 

[tbellemare]

Have you tried any other size cutters/tenons?

If they work, it would eliminate the machine...

Tom

 

[Birdhunter]

I had the tip of a cutter break off. The short cutter sweeps a smaller path than the normal cutter, thus would produce a mortise that isn't wide enough and would have a messy entry point.

The suggestion to try another cutter is spot on.

 

[grbmds]

If it's really just that they are a little to tight, then lightly sanding the ridges off the two sides of the Domino should make a difference. I've tried that when they are just a tiny bit too tight. I would agree, though, the mortise doesn't look quite right; a little ragged around the edges maybe.

 

[Holmz]

It looks about right if it was the 5-mm cutter.

 

[Monju123]

It looks about right if it was the 5-mm cutter.

Its not a little too tight. The Domino cant be installed into the mortice.

 

[tbellemare]

I have to assume you changed the cutter to a 6mm? The DF 500 comes with a 5mm cutter.

If you changed the cutter, it would be instructive to change it back to the 5mm cutter and try making a mortise with it. If you have the same issue, it would indicate that the machine has a problem. If the problem isn't the same, it would indicate the cutter.

Tom

 

[dltflt]

I had the tip of a cutter break off. The short cutter sweeps a smaller path than the normal cutter, thus would produce a mortise that isn't wide enough and would have a messy entry point.

The suggestion to try another cutter is spot on.

I had the happen also.  definitely worth taking a look.

 

[Holmz]

It looks about right if it was the 5-mm cutter.

Its not a little too tight. The Domino cant be installed into the mortice.

Just for kicks, I would still suggest seeing how a 5-mm domino looks in that mortice.

 

[Monju123]

5mm on left. I have problems putting the 5mm into the 6mm mortice. The width is very tight, but it can be done. Height wise, the 6mm mortice is too loose and the 5mm Domino wobbles up and down. The 5mm Domino into the 5mm mortice, tight width-wise but it can be driven in. The 2nd pic shows the 5mm Domino in the 6mm mortice.

 

[Bohdan]

I am wondering if the bit is oscillating widely enough.

To me it appears that the cutter is short, the tips of the cutter might be missing. This would give a slot that is the correct height but not the correct width.

 

[Cheese]

The thing that I first noticed is the sloppy hole that was created by the Domino. That's really unusual. They're always smooth and crisp. Consequently I'd check the Domino bit and look for any damage to it. The Domino holes in the photos below were produced with a #5 bit that has produced at least 200-300 holes in cedar, oak, maple, ply and glue-lams.

[attachthumb=1]

[attachthumb=2]

As Tom and others have suggested, I'd try the #8 or #10 bit and see if a Domino fits in those holes, if so, then I'd inspect the #5 bit closely or just swap it out for a new one.

 

[Holmz]

I am wondering if the bit is oscillating widely enough.

To me it appears that the cutter is short, the tips of the cutter might be missing. This would give a slot that is the correct height but not the correct width.

I thought that the oscillation was left and right with no up and down motion.

Let R = the radius of the cutter.
So R=2.5 or 3.0 for the 5 and 6 mm cutters respectively.

The height should be 2*R and the width should be 2*R + oscillation?
Or is it really possible to have the right 6-mm width and still have the length be short?

 

[GarryMartin]

The movement is only side to side, but it is in an arc from a fixed centre point, so if the cutter is short, the arc wouldn't be as wide and hence the domino slot would not be what you expect.

 

[Holmz]

The movement is only side to side, but it is in an arc from a fixed centre point, so if the cutter is short, the arc wouldn't be as wide and hence the domino slot would not be what you expect.

Good explanation.

(Even I am following you now... [embarassed])

 

[Monju123]

I have a new 6mm bit coming in on Tue. The tip of my current 6mm bit is not broken. If the new bit doesn't fix the problem, I'll probably send the machine into Festool. I will report how the new bit works out.

 

[Sparktrician]

I'm going to suggest that you examine how you hold and use your Domino tool.  It appears that it may be climb cutting a bit.  I'd suggest that you hold the fence firmly to the workpiece, then SLOWLY plunge it, holding it back by the PlugIt connector rather than by the barrel grip.  Listen to the motor as you plunge the tool.  There should be only a slight change in motor speed as you plunge.  If it's a dramatic change in speed, you're plunging too quickly.