Domino Tenons do not fit in mortise - not even close! Can width be adjusted?

[Lou Miller]

Dave,

I usually use my miter gauge and a fence mounted stop block on the TS. I clamp as many lengths together as I can and then crosscut them all in one shot. For safety reasons (meaning no flying tenons that are kicked up by the TS blade) I have a piece of plywood attached to my miter gauge. It extends about 1/2" past the blade. That's just enough to move all of the cut tenons far enough away from the blade so you don't have to worry about the blade catching them and throwing them at you. I just have to push the miter gauge all the way through before pulling it back. A ZCI installed in the saw is a good idea too. Crosscutting them is probably the fastest step in the operation. When I get to the point where the clamps are in the way (about 12"), I stop cutting and set those lengths aside. They get used eventually for things that I need to alter the lengths of the tenons for. I simply cut them on an as need basis.

There really is no reason you can't chamfer the edges or even leave them square if you like. I believe Tezzer chamfers his on his jointer, IIRC. I happen to have the router bits anyway and I don't mind rounding them over. Besides, it helps with alignment for frames and stuff if they fit perfectly. I make most of my tenons 10mm oversized in width to take advantage of the widest setting on the tool. I find that I almost never need a wider mortise to get things to fit, so I just use the widest setting with a wide tenon. That might not work for everyone (depends specifically on what you're working on), but it works for me very well. I'm doing cabinets the majority of the time. Perhaps with more complicated work, I'd use a smaller sized tenon and the wider settings on the tool.

I did some tables recently where making my own tenons really came in handy. I wanted to use two tenons where the rails and legs met. However, I didn't feel confident with two of them because there wasn't much space left between them. So I simply made two plunges with the tool. One from each side, and had the morises overlap. IIRC, I ended up with a mortise that was about 50mm wide. I then just made some loose tenons that fit and went from there. Super easy and super strong. I also really prefer using the same species of wood as the rest of the project too, and I almost never use beech, so making my own it is.

 

[Dave Ronyak]

Thanks for explaining fully, and sharing more great ideas, Lou.  I especially like the one about using the widest Domino setting, and wider shopmade tenons.

Dave R.

 

[jacko9]

Well, there certainly has been some interesting inputs from this group - thanks to all that have replied.

There seems to be some general agreement that the dominos don't fit "as expected", lots of suggested work around's (round over bits, sanding) and even those that make their own.

From reading your input and my experiments with the machine I know that I'm not using it incorrectly.  Since this is my first purchase of a Festool product I'm going to turn this one over to Festool and see what they have to say about.  Perhaps the dominos were designed to be 0.03 to 0.40 thousands-inch wider than the slot.  Seems odd to me, but you never know...

I will post a reply of my experience with Festool customer service on this issue.  As this is my first Festool product purchase I'm hoping that they will live up to their reputation.

Thanks again,
DNRDHS77

dnrdhs77 - Did you ever hear from Festool on this topic?  If so, did they give you an optimum joint clearance for the mating fit?

>

 

[festoller]

Same problem here! These are my measurements:

Domino Standard (5x30)
28.2 mm (lenght)
19.0 mm (width)
05.0 mm (height)

Domino Sipo (5x30)
28.2 mm (lenght)
18.8 mm (width)
05.0 mm (height)

Mortise (5 mm bit, 15 mm)
16.1 mm (depth)
18.5 mm (width)
05.0 mm (height)

Although in my opinion it's both hight and lenght.

The first few mortises have been made without any adjustments right out of the box, but I'll try another run with adjusting the widht while the Domino is running. Also I still have to speak to Festool support and try to find out if this is normal.

Full post: Domino Problems

 

[slb]

As has been noted, there is a difference between tight fit in width and thickness.  I vaguely recall reading somewhere that the little ridges along the edges of a domino are deliberately a bit tight and are meant to crush during insertion, maybe to allow air and glue to escape?  But for me the real problem is with thickness.  Measuring stock Festool dominoes with a caliper, I have found that only around one in ten measures at or below the nominal thickness.  The majority measure between 0.04 and 0.1mm oversize, no matter how old or new, and no matter how I store them.  If I plane or sand these down to nominal thickness, I can push them into the mortises by hand or at worst with very light hammer taps, which leads me to think that the tight width is a much lesser problem.  As others have noted, drying in the microwave helps, though I've often had some still oversize after cooking.  Usually I give each one a couple of swipes with a block plane, which takes only a bit longer than microwaving them.

I find it difficulty to think that a company as fanatical as Festool would tolerate sloppy manufacturing, so my guess is that they are having the dominoes made to within a close tolerance of nominal size, and are not accounting for the empirical fact that nearly all of them subsequently expand.  Wouldn't it be better to make them a shade undersize, expecting that most would then expand up to nominal?

 

[Monju123]

2 words, micro wave. Nuke those boy just a little, (they get hot fast), and they go in much easier.

 

[Toller]

2 words, micro wave. Nuke those boy just a little, (they get hot fast), and they go in much easier.

Can you give us a hint as to what time you have found to work?

Getting them out again after dryfitting is a challenge, but I have never had a serious problem getting them in.  But I would like to try the microwave to see what happens.

 

[fshanno]

I don't think of it as loose tenon joinery, I think of it as tight tenon joinery.  I always thought that was the real inspiration of the thing.  This tightness of the stock tenons is part of the innovation and, frankly, the brilliance of Festool's design.  They tuned the tenon sizes so that they are almost always quite tight fitting despite all sorts of variables.  On the narrow setting I always have to use a mallet.  Sometimes I have to tap quite hard to seat the things.  Nevertheless the stock tenon sizes are just about perfect for me.

 

[Toller]

I don't think of it as loose tenon joinery, I think of it as tight tenon joinery.  I always thought that was the real inspiration of the thing.  This tightness of the stock tenons is part of the innovation and, frankly, the brilliance of Festool's design.  They tuned the tenon sizes so that they are almost always quite tight fitting despite all sorts of variables.  On the narrow setting I always have to use a mallet.  Sometimes I have to tap quite hard to seat the things.  Nevertheless the stock tenon sizes are just about perfect for me.

I have never had a domino fail, but always wondered just how much glue can be in a joint that tight.
When you do a normal glue up, the glue has a few minutes to soak in the wood before you clamp it; no time at all in a domino.

 

[Monju123]

I microwave them only a few seconds, maybe 10 or so. They really do get hot fast, so don't just grab a handful, but it does shrink them just a smidge.

 

[MarkF]

Getting them out again after dryfitting is a challenge, but I have never had a serious problem getting them in.  But I would like to try the microwave to see what happens.

[sad]

I mentioned this in another thread and have done away with dryfitting Dominos and pulling them out, etc.  It is a waste of time and effort.  I call this the "Half Dry Test Fit".

I mill one mortice on the tight fit setting and the opposing mortise on the next widest.  Then I glue all the Tenons into the tight side and hammer them home.  After a few minutes to allow the glue to start to dry I test fit the piece without glue in the wide mortices or joint edge,  It's much easier to use the leverage of the whole workpiece than to try to pull each individual tenon.  If I'm not happy with the fit/allignment, I pull it apart, use a flush cut hadsaw to remove the protuding tenons, glue the offcut tenons in the opposite mortice, remortice in the appropriate places and try again.  If ok, I pull it apart, apply glue to the oppsing mortices and both edges and whack/clamp it together.   

 

[bonesbr549]

I'll add my 2 cents worth.  I've had the domino since it came out and used it a lot.  I use the tight fit (I) on one side of the joint and the next widest setting (II) on its mate.  this allows for lateral adjustment to a final fit.  Secondly, I have a set of tenons I call my test fit tenons.  I take a 60 grit sanding block and lightly hit both sides to thin it just a hair.  Finally I take a utility knife and shave just a hair off the edge of the tenon so you have a bit of air space around the edge when inserted.    They still have to be tapped in with my deadblow hammer and to remove I use a pair of challen lock pliers and grip them gently and tap the bottom side of the pliers with my hammer and they come right out with a couple taps.  When I do the real glue up I use fresh tenons.  If the piece has a lot of tenons that need to be glued ut once like a long panel etc, I'll glue one side in and then glue it to its mate after that side is set.  Not had a single issue. 

 

[Toller]

If the piece has a lot of tenons that need to be glued ut once like a long panel etc, I'll glue one side in and then glue it to its mate after that side is set. 

When you put the domino in, a good amount of glue is squeezed out.  You would have to carefully clean all that up because when you put the panel together it would be in the way.  Wouldn't it?