Domino Disaster

[deepcreek]

I've cut hundreds of Domino 500 mortises but rarely use the 4mm bit.  The bit in question has made a couple dozen cuts and is genuine Festool.

I was working on a small box today and the Domino cutter kept grabbing and skating as I plunged.

The mortise in the attached pictures was the worst one and I just stopped at that point.  It's a hot mess.

The wood is White Oak.

Any ideas on what is going on?

Thanks!

Joe
[attachimg=1]

 

[squall_line]

That looks like a chipped/dull/clogged bit to me.

 

[ChuckM]

If the cutter isn't the culprit, then likely it was the plunging speed. Plunge slowly to let the cutter do its job. The 4mm cutter is prone to break if it is jammed or hits wood at an angle.

 

[Cheese]

Something moved...the Domino depths are different, the Domino alignments are different. If there was no movement what so ever, then the Domino mortise would appear to be the same even though it may be rough looking. The depth levels are the clue. It could even be a combination of the Domino machine moving along with the Domino 4 mm bit breaking.

 

[tjbnwi]

Do you have the plunge depth set to 20?

Tom

 

[Birdhunter]

My guess is that the tip broke off.  Do you have a backup 4mm bit to compare to? If not, I can measure mine. Those tiny bits can be fragile and oak is a tough wood.

 

[guybo]

Hi, you can see by the photo that the index for the mortice changed from widest to tight.This happened to me talked w/ lester about this,(remember they say to change width while running) mine did it on its own.I found the housing screws to be somewhat loose,retighten ,and it has only happened twice again, since 2010.It could be op error but most of festools are held together and any mechanical looseness is determined by the housing,think thoses who swore running their sanders for hrs. helped with heat,i.e. it got wore in. anyway you can see the steps of the bit in the slot. btw been using the 4mm for cabinet alginment works well. guy

 

[deepcreek]

That looks like a chipped/dull/clogged bit to me.

It shouldn't be dull has it has very few cuts on it.  I verified that it was not clogged.  I will probably go ahead and replace it anyway.

If the cutter isn't the culprit, then likely it was the plunging speed. Plunge slowly to let the cutter do its job. The 4mm cutter is prone to break if it is jammed or hits wood at an angle.

White Oak is pretty dense and I was trying to maintain a slow, steady controlled plunge.  Obviously, I lost control despite having a firm grip on the tool.

Hi, you can see by the photo that the index for the mortice changed from widest to tight.This happened to me talked w/ lester about this,(remember they say to change width while running) mine did it on its own.I found the housing screws to be somewhat loose,retighten ,and it has only happened twice again, since 2010.It could be op error but most of festools are held together and any mechanical looseness is determined by the housing,think thoses who swore running their sanders for hrs. helped with heat,i.e. it got wore in. anyway you can see the steps of the bit in the slot. btw been using the 4mm for cabinet alginment works well. guy

I almost always use the middle width setting and know to only change it while running.  The knob does feel sloppy in the middle setting.  My Domino was made in 2007 so it has a lot of use.  Also, this version was made before the 4mm bit was even introduced.

Do you have the plunge depth set to 20?

Yes, it's set to 20.

My guess is that the tip broke off.  Do you have a backup 4mm bit to compare to? If not, I can measure mine. Those tiny bits can be fragile and oak is a tough wood.

I compared the 4mm bit to a 5mm bit and the end cutter geometry looks the same so I don't think it's broken off. 

Something moved...the Domino depths are different, the Domino alignments are different. If there was no movement what so ever, then the Domino mortise would appear to be the same even though it may be rough looking. The depth levels are the clue. It could even be a combination of the Domino machine moving along with the Domino 4 mm bit breaking.

Something definitely moved!  I feel like I did everything right and the bit is not broken.  That's what has me stumped.

 

[Michael Kellough]

Try a couple on the narrow setting, on the same wood. If they look good try the middle setting again.

I don’t know what the mechanism is that swings the spindle but since you use the middle setting a lot (as do I) maybe some parts have worn.

 

[fraz]

Maybe not disaster.  Most of the time when I have had Domino missteps, it isn't a big deal because the mortise and tenons are typically all hidden by joining boards and full of glue so you never see them.  If I cut one in the wrong place and it is still hidden, just glue and tap a Domino in there, flush cut it, and carefully recut the mortise.

As for broken bits, brand new ones can get the tip broken.  My first 5mm broke on me in very soft ply after like 10 cuts with slow plunges.  Usually the tip gets embedded in the wood somewhere and if you hit it while plunging can create some violent movement.  Do yourself a favor and get a strong magnet and run it over the mortises and see if it sticks to any metal in there.  If you find it, dig it out and try again.

 

[Packard]

I don’t used a Domino, so take my question with that in mind.

To my eye, it looks like the machine shifted in the middle of the cut.  Is there any chance that might have happened?

 

[RussellS]

Hi, you can see by the photo that the index for the mortice changed from widest to tight.This happened to me talked w/ lester about this,(remember they say to change width while running) mine did it on its own.I found the housing screws to be somewhat loose,retighten ,and it has only happened twice again, since 2010.It could be op error but most of festools are held together and any mechanical looseness is determined by the housing,think thoses who swore running their sanders for hrs. helped with heat,i.e. it got wore in. anyway you can see the steps of the bit in the slot. btw been using the 4mm for cabinet alginment works well. guy

I agree with your assessment.  Domino started in the middle setting.  Owner plunged it in a bit, 1/8".  You can see the bottom/left is about 1/8" deep.  But then as it was cutting the top/right, it jumped from the middle to narrow setting.  Did not cut quite as deep on the top/right.  Less than 1/8" deep.  And as the owner kept on plunging, the full depth mortise was cut on the narrow setting.

Measure the width of the mortise.  The wider shallow cut.  And the narrow deep cut.  I bet they measure up exactly with the middle and narrow settings widths for the Domino.  Good evidence that the Domino changed from the middle to the narrow setting in the middle of the plunging.

 

[deepcreek]

UPDATE - I agreed with the assessment that the mortise width was slipping during the cut and sent it in for service.

Festool Service said the width mechanism needed adjusting but they didn't have to replace any parts.

No charge to repair a 13-year old tool other than my out of pocket postage to send it in.

Thank you, Festool.

Thank you very much!

 

[Bob D.]

Good to hear they took care of you.

Is that an adjustment that has to be done by Festool or something a user could do?

 

[Crazyraceguy]

That's a great outcome. Good on em.

 

[waho6o9]

Good news!

 

[deepcreek]

Good to hear they took care of you.

Is that an adjustment that has to be done by Festool or something a user could do?

I called and spoke with them but they only said it required recalibration and did not show excessive wear.  I didn't ask for specifics.