# John Heisz box joint jig question



## deadherring (Nov 25, 2013)

Hi folks,

I made the John Heisz box joint jig a while back and used it on some test pieces, but now am planning to use it on a hardwood box and want to make sure I have it all down before I started cutting into my nice walnut.

My box dimensions are: (2) A 8" wide x 4 ¾" high; (2) B 4 ¼" wide x 4 ¾" high. I'm going to cut a groove into the bottom (1/2" up from the bottom) for the bottom and will glue on a cover.

My question is, in this video

John says to cut the side long so you can trim them down so the box joints line up and fit together.

So, I wanted to verify the procedure and order of operations. I kept B at 5 1/4". Do I:

1. Cut the box joints for A and B
2. Fit together and mark where to cut down B 
3. Cut down B
4. Cut the groove for the bottom panel in A and B

If yes, how do I ensure where exactly to cut down B so that the bottom and top lines up with B? I think the top has to be perfectly flush in order to glue down the top of the box on top of it?

I hope I am making sense. Let me know if anything is unclear.

Thanks,

Nathan


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## MadMark (Jun 3, 2014)

Your sides need to be an integer multiple of the finger size to make things easy. If its a 2x multiple (finger + slot) then you can cut all four sides at once and flip the end pieces and it should come out right.

Any error in your rip will show 2x larger at the corners.

Ripping the slots after the fingers insures you have everything oriented correctly. Stopped dados won't show but are extra work.

Alternately just make a 1/2" thick rectangular bottom and glue it in flush when you glue the box. No slots needed and plenty of strength for anything one person is apt to tote.

The top shouldn't be glued, it should be hinged or a slider. (I like sliders 'cause i don't need hardware,)


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## RichT (Oct 14, 2016)

> Your sides need to be an integer multiple of the finger size to make things easy. If its a 2x multiple (finger + slot) then you can cut all four sides at once and flip the end pieces and it should come out right.
> 
> - Madmark2


Actually, a 2x +1, since a proper box joint has a finger top and bottom.


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## deadherring (Nov 25, 2013)

> Your sides need to be an integer multiple of the finger size to make things easy. If its a 2x multiple (finger + slot) then you can cut all four sides at once and flip the end pieces and it should come out right.
> 
> Any error in your rip will show 2x larger at the corners.
> 
> ...


Thanks for the reply. Can you clarify a bit for noob? I'm not 100% sure I understand what you mean by:

Your sides need to be an integer multiple of the finger size to make things easy. If its a 2x multiple (finger + slot) then you can cut all four sides at once and flip the end pieces and it should come out right.

I am planning to (probably) use 3/8" finger joints so I have a 1/8" blade in my saw, will cut three passes then 'click' three times, then 3 passes and repeat.

So are you saying I should cut A and B together and it should fit? Do I have both A and B at their final sizes and then cut together? Or…?

Sorry if I am not following.

Nathan


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## woodbutcherbynight (Oct 21, 2011)

Get a box joint set, Freud makes one that will let you cut 1/4 or 3/8. Much more accurate and alot less work.

LINK

As for the bottoms dry fit assemble the box. Use tape or a strap to hold together. Then come back with a 1/4 router bit and make a nice channel for your bottom. Test fit bottom, then assemble all as one.


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## MadMark (Jun 3, 2014)

Your stock for the sides wants to be a multiple of the finger size so that everything comes out even and you don't have a fractional finger at one end. For a 3/8 joint you side need to be 1-1/2, 2-1/4, 3, 3-3/4, etc. The steps are 2x the size of the finger spacing so you get a full finger/notch multiple.

If you are on the 2x spacing you can gang cut all four sides at once and just flip the end pieces and all will fit.

I've made over a hundred of these box jointed PO Box door banks:









Front









Back


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## RichT (Oct 14, 2016)

There is supposed to be a finger or a slot at both ends of the joint-not a finger at one end and a slot at the other. There should *not* be an equal number of fingers and slots.

This is a box I made from zebrawood using the Incra I-Box.


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## MadMark (Jun 3, 2014)

There *is* a finger at both ends!

Gang cutting saves 4x the work. Each piece with a notch at one side and a finger at the other is both easier to cut and less prone to error that having both sides end with fingers or a notch.

After 100+ of these banks I learned a *lot* about making box joints quickly and accurately.


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## woodbutcherbynight (Oct 21, 2011)

> There *is* a finger at both ends!
> 
> Gang cutting saves 4x the work. Each piece with a notch at one side and a finger at the other is both easier to cut and less prone to error that having both sides end with fingers or a notch.
> 
> ...


How did you do the back??


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## MadMark (Jun 3, 2014)

Flat cut it to fit *during* glue up. Everything was cut using Incra rules & tools. Backs would drop in place and settle with perfect fit like a piston. Once glued and clamped that was that.

I use flat edged bottoms in most of my boxes. The long parallel grain glue lines give massive strength without dados. Trying to assemble box joint boxes with dado'd bottoms is a five handed logistical nightmare. DAMHIKT

For most small work simple butt joints work well.









All butt joints box back









Front


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## woodbutcherbynight (Oct 21, 2011)

> Flat cut it to fit *during* glue up. Everything was cut using Incra rules & tools. Backs would drop in place and settle with perfect fit like a piston. Once glued and clamped that was that.
> 
> - Madmark2


Thanks, I have been experimenting with a 45 degree router bit on some test parts bins after the box is glued up. Then drop them in with a wedge fit. Add some glue and a clamp. Different method, just trying it out.


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## MadMark (Jun 3, 2014)

Is the box going to be big enough to need that kind of strength? You making a sample case for anvils?!

Never thought about a beveled bottom. I think it would be hard to cut without a lot of chipping. Getting the bevels to mate sounds hard. Give it a try and let me know. I'd be interested in seeing your results, good or bad.

*PS:*
Beveled bottom would have wide side out instead of in. Maybe cut with a dovetail bit for wide side in?


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## woodbutcherbynight (Oct 21, 2011)

> Is the box going to be big enough to need that kind of strength? You making a sample case for anvils?!
> 
> Never thought about a beveled bottom. I think it would be hard to cut without a lot of chipping. Getting the bevels to mate sounds hard. Give it a try and let me know. I d be interested in seeing your results, good or bad.
> 
> ...


Not particularly, but ya never know. I saw something that gave me the idea and decided to experiment. As I can always use certain size parts bins I made something I will actual use and plan to see how it works.


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## MadMark (Jun 3, 2014)

Cool. I'm interested in what you come up with. Post pics when you can.

Good luck!


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