What size tenon?

[bigarm]

I am finally going to use my Domino 500.  I bought it a little over a month ago and am just now going to build something with it.  Been busy finishing the wood shop and staining the house and deck and can finally get to it.  I am going to build a medicine cabinet out of cherry wood.  The carcass will be about 4 1/2" a little less than 1" thick (4/4 cherry, but I ran the pieces through a planer).  To connect the pieces what size tenons should I use?  I will also be making the door frame with approximately 2 1/2" rails and stiles with either a glass or mirror inset.

 

[TOOLTOWN]

We generally follow the rule of thirds.

For 25mm stock (1 inch) an 8 mm tenon is a good choice.  (25/3 ~ 8 )

For narrow stock you can always downsize, but upsizing will begin to weaken the joint as there will not be enough meat left on either side of the tenon.

Ken

 

[bigarm]

Thanks.  I will need to measure the finished size, but at worse I could use 6 mm tenons.

 

[Brice Burrell]

Thanks.  I will need to measure the finished size, but at worse I could use 6 mm tenons.

I don't go by the old rule of thumb of 1/3 the thickness of the material, but rather think about what size tenon will provide enough strength for the project.  I think the 6mm tenon will work well.  The 5mm tenon would probably work also assuming you aren't using a think piece of glass/mirror.

 

[#Tee]

the df500 comes with a 5mm bit so naturally just buy 5mm dominoes which is suitable for 1/2in ply. i used 5mm on 18mm birch ply.

 

[Stone Message]

Yes, the rule of thirds works well. In solid wood you can push it slightly - like putting an 8 mm domino into 20 mm stock but in sheet material, especially MDF it pays to be on or under the 1/3rd.

If you are putting dominos into weaker stock, especially MDF, then watch out for hydraulic locking whereby the domino makes a seal as it goes into the slot and pressure builds up inside the joint. This can rupture ply and MDF and I have seen it split solid wood. To overcome the worst of this just tap the domino in a bit at a time to allow the pressure to equalize as it goes in.

If you would like some more ideas of what you can do with a Domino machine that will be useful in the house then try a simple chair:



I made mine from cherry so if you have any left over from the cabinet it could be used.

Peter

 

[jools]

Good advice above. I would add always use the same face of your pieces to reference the domino, practice first on some scrap, always clamp your work or use dogs and sand a few dominoes and use for dry fitting before glue up.  All this I have learned on the fog from videos and fellow foggers.

 

[ear3]

Also, it pays to do some calibration at the outset.  Normally the Domino comes out of the box pretty finely calibrated, but it's actually possible to get within a couple thousandths of an inch if you want.  The two possible calibrations involve the edge dogs, and then the cursor.  Your kit should have come with extra dogs that are .6 mm smaller than the one installed.  If you do a test and find there is an offset, then you can swap out one of the dogs to get a closer approximation.  You can also adjust the cursor so that it is truly dead center with the mortise centering line, if it's not already.  You can refer to half inch shy video on this process:

 

[bigarm]

Played with the Domino today.  Found out the 6 mm tenon was too long for my use.  Put a hole (well a divet I guess) in my assembly table.  5 mm will work well. Had no idea about the calibration OR why those extra pieces were in the systainer.  Seemed to be pretty good, but I will check the calibration at some time.  I do not have a wheel marking gauge.  Is there another way to do the line? 

 

[ear3]

You could use a slightly bigger piece of wood -- something that can be clamped down while you're marking it -- and draw the knife line with a combination square, holding the blade at the end of the ruler -- you just have to make sure you're holding the blade at the same angle.  You could get fancy as well and make your own marking gauge, which is pretty easy to do -- you don't need something that's accurate in terms of measurements, just something that produces repeatable marks.

In truth, though, I actually just eyeballed the adjustment based upon the initial offset (which was minimal to begin with), and skipped the tape step.  I got lucky and managed to get it dead on with the first adjustment.

EDIT: As Peter says below, there is still a slight amount of wiggle room (with a little help from a mallet) you can get even when using the narrow mortise setting, so you don't have to stress if your machine has a slight offset and you haven't yet done the calibration.  Of course, if you use the wider mortise setting then the offset is completely moot anyway.  But for me, doing the calibration and bringing my Domino to dead-on was a moment of great personal satisfaction, knowing that I could have 100% faith in the accuracy of my machine.

Played with the Domino today.  Found out the 6 mm tenon was too long for my use.  Put a hole (well a divet I guess) in my assembly table.  5 mm will work well. Had no idea about the calibration OR why those extra pieces were in the systainer.  Seemed to be pretty good, but I will check the calibration at some time.  I do not have a wheel marking gauge.  Is there another way to do the line?

 

[Stone Message]

Played with the Domino today.  Found out the 6 mm tenon was too long for my use.  Put a hole (well a divet I guess) in my assembly table.  5 mm will work well. Had no idea about the calibration OR why those extra pieces were in the systainer.  Seemed to be pretty good, but I will check the calibration at some time.  I do not have a wheel marking gauge.  Is there another way to do the line?

This is a good reason not to put your hand behind the wood to react the pressure during a Domino cut.

Also, before you start any batch of Domino work check 4 things...

    - Have I got the right size cutter installed?
    - Have I set the width of slot (narrow, middle or wide) ?
    - Is the depth setting right?
    - Is the height setting right (use either the quick setting or precise setting) ?

For marking I almost always use my Incra Precision "T" Rule. It takes the fuss out of the process and is very precise.

When doing Domino jointing there is at least 0.5 mm or even as much as 1 mm of wiggle room when fitting dominos on the narrow setting. Unless I am doing an expansion (breadboard) joint I always use the narrow setting on the DF 500.

Good luck. The Domino is one of the top 3 amazing tools from Festool.

Peter

 

[Holmz]

... The Domino is one of the top 3 amazing tools from Festool.

Peter

I agree. I used 5-mm in 16-mm jarrah.

6 or 8 mm sounds right. (In real wood 8-mm)
They are incredibly strong.

 

[bigarm]

Made my first project with the Domino today.  Just a simple shelf for spring clamps, but worked well.  I also kind of checked the calibration and it seems pretty close to right on.  Didn't have a 10 torx to adjust anyway.  Had a 20 and a 15, but no 10.  Anyway, I just carefully made a couple of the cuts and they lined up pretty good with just a touch of offset.

 

[fdengel]

Played with the Domino today.  Found out the 6 mm tenon was too long for my use.  Put a hole (well a divet I guess) in my assembly table.  5 mm will work well. Had no idea about the calibration OR why those extra pieces were in the systainer.  Seemed to be pretty good, but I will check the calibration at some time.  I do not have a wheel marking gauge.  Is there another way to do the line?

No reason you could not cut the dominos to make them short enough to fit if needed.