Domino Size Advice

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Established Member
22 Mar 2017
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South Yorkshire
I've got a project underway that initially I was going to make with traditional M&T joinery.

However, having treat myself last year to a Domino 500, i've revised the design to use dominoes.

My question is - which size domino to use and whether to use 1 or 2 dominoes per joint? Here are the dimensions of the joint.



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You need 2 dominos to stop it twisting.

The 21mm thickness is halfway between the thirds rule for 6mm and 8mm dominos. The theory is if the stock you are using is soft (for example MDF) you should use the 6mm as it leaves more strength around the domino.

In reality 6mm or 8mm should be fine whatever, obviously an 8 x 50 gives more glue area then a 6 x 40.
I agree. I would use 8mm Dominoes, two of them.
The nice thing about Domino joinery is that you are not actually restricted to the standard widths. It is easy to merge a couple of slots together to make a wide one and then mill your own tenon material to suit.
I even have aWaggleometer (TM)* to help me decide what size tenons to use.

*Slightly disappointing to see that it has had only 5K views in 13 years and that it has as many thumbs down as thumbs up. It's actually a very useful little gauge, I use mine regularly. And you have to admit, it presented by a very youthful and sartorially elegant gentleman.

OK, possibly not my finest videography.
LOL. It originated as a joke and then kind of got out of hand...
Actually I loved that shirt, I wish I still had it. You know, for special occasions.
Steve Maskery":2j01ow5h said:
LOL. It originated as a joke and then kind of got out of hand...
Actually I loved that shirt, I wish I still had it. You know, for special occasions.

I watched it twice, because I could, and I am confident that I used to have a shirt somewhat like that, in about 1992. Nothing wrong with the shirt.

It's a very nice shirt. :oops:
I like the shirt.
It's like watching a talking, moving Mondrian painting.

Is there a follow up? A jiggleometer perhaps, in the style of Picasso?

Sent from my SM-G973F using Tapatalk
The original idea was that if I ended up doing a series of films, I could have a different whacky shirt for each one. But it kind of backfired. I got a lot of flack, people didn't get it. In fact, I've had more compliments in this thread than in the last 14 years since it was filmed :)

I'm not sure that I make it clear in that clip, but each Waggleometer has 9 setups.
There is a single mortice
There is a double mortice produced with the pin set against the left-hand end of the first
There is a double mortice produced with the pin set against the right-hand end of the first

All of them are produced in all three Waggle settings.

Sorry, this thread appears to have got hijacked.
Steve - thanks for the original idea. I made one last night, i don't think it is exactly the same as you describe above. Mine has 4 sets of "waggles" one for the 5/6/8/10mm cutters. I then transferred the centre and edges of each mortice to the edge of the MDF. Now I can use it to easily mark out where I want the domino, and easily see where they will end up e.g.

I've got a forthcoming project that will use a ton of these - so this will be very handy.
I'd completely forgotten that my first one was exactly like yours, Fezman. This is my set:

Looking at them now, I think my description in my earlier post is not quite accurate. It looks like I've only done the job with the pin moved over to the LH side of the original mortice.

I also have another simple but useful setting out tool for the Domino. It is just a piece of Perspex with a fine line scratched into the underside to make a cursor. It is exactly the same distance from the edge as the centre of a Domino bit is from the sole of the machine. It's useful when I want to place a Domino further away from the edge of a board than the machine's fence will allow.

I simply draw a pencil line for the centre of the Domino, line up the cursor with the pencil line and clamp a block up against it to act as a fence. Now if I press the sole of the machine against that fence and plunge, the mortice will be excatly on the pencil line.

I have one edge scratched for my Domino and the other for my BJ.
perspex setting plate.png


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