Box or Dovetail joint quantity

[Esqy]

So far, I've been butt-jointing any box-like things I make - but I wanna try some more fancy joints.
I've seen many guides on making a router table or tablesaw jig but I have questions...

What I've struggled to find, is how to decide how fat to make the fingers.
Sizing them as 1/2 the thickness of the wood seems to be the general consensus for making it look pretty, However when I'm making box-like items, they can be all sorts of various heights.

So, for example - My current plans have 3 different boxes - 220mm, 270mm and 108mm

(The latter was something I was making ad-hoc, and for round 2 of it, I'll probably round out the numbers, but it's a good example of what I'm after)

So, When box jointing - Or dovetailing - how does one decide on the size of the fingers to ensure that my last one isn't veneer thickness?
Is it just a given that, unless the height of the box is pretty specific, there will be 1 joint with slightly smaller fingers?

Is it just a case of Height divided by Bit size and aiming for a whole number?

If I'm building a jig, I might aswell build a few, so what are the, say, top 3 bits that cover most sizes?
Is it just one of those things that the end-fingers are commonly slightly smaller that the rest?

I feel like I might be overthinking this - 's what happens when I'm at the computer instead of the workshop!

 

[Just4Fun]

I use hand tools so I can choose any size I want, not being limited by the size of a router bit or something. I don't have a consistent approach, I just do what takes my fancy at the time. Sometimes I create equal sizes using dividers. Sometimes I just do it by eye without measuring or marking anything but I haven't done that often as my eye seems not to be very good at picking good-looking sizes. If I measure and will have an odd-sized finger I usually try to locate it in the middle of the width rather than at one edge.

 

[Blackswanwood]

There are loads of articles out there on this for dovetails but I'm a fan of the approach that @Just4Fun takes.

I know the author can cause an allergic reaction for some but this may help ...

dovetail-sizing-keep-simple

While deciding the spacing out putting any extra odd mms where the saw line will go through the pins when separating the lid and body of the box can be useful.

 

[Tris]

How complicated do you want to get? This thread shows a really impressive jig

Thread 'My latest jig creation' My latest jig creation

 

[Jacob]

...

So, When box jointing - Or dovetailing - how does one decide on the size of the fingers to ensure that my last one isn't veneer thickness?
Is it just a given that, unless the height of the box is pretty specific, there will be 1 joint with slightly smaller fingers?
...

You decide on where the first and last one will sit and divide the rest of the space between them equally.
"Box" joint is really a machine only joint - if doing them by hand there is no point in not making them as dovetails, it's just a different angle.
Most dovetails were done freehand without jigs or guides and it's a good place to start.

 

[andrew_2]

I looked at lots of box joint videos on youtube and some are incredibly complex, and look like they give superb results. Then I found this one, which is dead simple.

I've tried it out on 7mm and 9mm fingers and it gives a very acceptable result. I don't think it's absolutely perfect machine quality, but I reckon that's more me than the tools.
So the tests I made were done on boxes where the fingers were multiples of either 7 or 9mm, but you can make the fingers whatever fatness you like. No veneer flappy bits top and bottom.

 

[Fitzroy]

I think I'm saying the same as Jacob, but use a spacer at the start of the set of joints to get the first and last section a similar size and avoid the veneer thick issue.

I looked at lots of box joint videos on youtube and some are incredibly complex, and look like they give superb results. Then I found this one, which is dead simple.

I've tried it out on 7mm and 9mm fingers and it gives a very acceptable result. I don't think it's absolutely perfect machine quality, but I reckon that's more me than the tools.
So the tests I made were done on boxes where the fingers were multiples of either 7 or 9mm, but you can make the fingers whatever fatness you like. No veneer flappy bits top and bottom.

ah, Mr Maskery formally of this parish, much missed.

 

[recipio]

Box joints are strictly machine made - life is too short to cut them by hand. I am fortunate to have a dado blade so I can adjust the width of the joints but of course they can be cut with different router bits. I make a test cut and then measure that accurately with a vernier , then multiply by the number of joints to get the overall height of the box.
Sometimes I find I have a sliver of wood on one edge after machining and all four sides can then be run through the table saw for uniformity.
Box joints have a few unwritten rules. The smaller the box the thinner the joints should be and aim to have the top and bottom ' finger ' at the front/ back rather than an end grain piece. It just looks better. Generally for something like a 300 x 200 mm jewellery box , 6 mm / 1/4" joints look good. To use large 12 mm joints for instance the box should be about 300 mm / 12 " high. For milling a groove to accept the base it's so tempting to use the table saw but you will then create a gap through two of the fingers on each piece.. Filling with a plug never seems to work so the only option is to drop the piece on to a router bit in a table and leave a tiny piece of wood at the end of the finger so a gap does not appear.

 

[Jacob]

Or get a better machine?