Corner Joint

[Nicholas Lingg]

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Does anyone recognize this joint and what it might be called. This one is on a compound angle, so I'm thinking it has to be cut by hand.

[David Weaver]

It's some type of locking miter joint. it's got an extra little finger vs. what you see on the router bits that are sold now to make that type of joint - pretty cool, it locks in both directions.

I wouldn't be surprsied if it was created mostly with table saw cuts, though.

[Zach Dillinger]

I've seen this style of joint referred to as a drawer lock joint. I can't see the improvement over dovetails if cutting this by hand, and it looks one heck of a lot harder than dovetails to cut. I'd agree with David that it probably was cut with an unmentionable apprentice.

[Paul Saffold]

http://www.rockler.com/product.cfm?page=2142&site=ROCKLER

This is Rockler's version. Most any supplier of router bits has a version.

[Joe Bailey]

Looks to me like that Rockler bit is missing the very thing that makes this joint complex - the cross lock.

[Paul Saffold]

Thanks Joe, you're right. I didn't look close enough. And I didn't read David's post obviously.
Paul

[george wilson]

That is called a cash register joint. A locking drawer joint is also correct,I suppose. Usually cut with special router bits.

[Bill White]

That is one cool tool tray (I guess for tools).
Would like to see more detailed pics with approx. measurements.
Bill

[Jim Koepke]

It looks like the bottom is missing.

jtk

[Jim Neeley]

That just makes the tray lighter to carry, Jim! :p

[Tony Shea]

I think it has a glass bottom. Typically what you see in old tool boxes, a nice see through glass panel bottom.

I also doubt that this joint is done by hand. It is interesting though due to the extra finger in there. I have never actually seen this type of joint that locks in both directions.

[Nicholas Lingg]

I took the bottom off to make sure the joint went all the way throught,"it Does". It measures 13 X 9 at the top. The sides are tapered and the joints are not uniform enough to be cut on a machine,and with compound side I'm not sure they can be.

[george wilson]

The box pictured is a knife box for eating utensils.

[Joe Bailey]

George,
The breadth of your knowledge never fails to amaze me.

[george wilson]

I've seen many of those old knife boxes at flea markets.

[Ryan Baker]

That's a cool joint. I think I am going to have to try making one ... though the compound angle may add some thinking time to the process...

[Greg Wease]

I have a book by Sam Allen, Wood Joiner's Handbook, that has a similar joint he calls a "double-lock corner joint". It has the same locking elements but without the mitered corner or the compound angle. Perhaps you could call the joinery on your piece "double-lock miter joints".

[Nicholas Lingg]

If you make one before I do let us know how you get together. I don't see how the compound side let it go together

[Ryan Baker]

If you make one before I do let us know how you get together. I don't see how the compound side let it go together

Yeah, I know what you mean. I think it's possible (pretty much has to be doesn't it) to just cut the joint parallel to the compound edge and then just slide the pieces together. But I am really tired right now and my brain isn't quite seeing the 3D geometry of it completely clearly.... I'd bet it isn't as hard as it looks.

[mike holden]

Is there a small amount of end grain showing on the right side board as shown in you picture? If so, then the joint should be easy to cut on the table saw. The tricky part is in cutting the boards at the compound angle. Chad Stanton posted videos on how to set up the compound angles easily and without math, try googling "wood chopping time" to find Chad's website.
Mike

[Nicholas Lingg]

With enought time and trial and error I think it is possible to make a fixture to cut the joint. But how do you put it together?

[mike holden]

With enought time and trial and error I think it is possible to make a fixture to cut the joint. But how do you put it together?



It slides together. Similar to sliding together a sliding dove tail joint.

[Tom Vanzant]

The locking joint is created with this router bit by milling one piece flat on the router table, and the other vertical against the fence. Fine-tuning of the bit height and fence location is involved, but once adjusted, all goes smoothly.

[Ryan Baker]

So I decided to play around a bit and try out a sample of this joint just for fun. Don't beat me up too badly for the quality of the fit. This was done as a quick experiment -- and completely with hand tools.

The first thing to note, as Mike mentioned, is that the miter does not come all the way to the corner. I marked up the previous picture to show the alignment more clearly. You could run the miter to the corner, but it would be harder and probably not as strong. The four intervals on each side appear to be different sizes in the picture. I chose to make them all 3/16", which works out well with 3/4" stock.

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Cut off the side pieces square at the desired bevel angle. I chose to use 20 degrees here, which is a lot, but this is just an example. You want these edges left square at this point to give a surface to work off of. The rest of the joint is mostly just cutting a series of grooves in the right places, always keeping them parallel with the angled end. The trick is to cut them in the right order so that you don't cut away a surface you need to run your plane against. Here are my pieces layed out for cutting.
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I found that plowing across the end grain in this popular was smooth as butter. Plowing across the faces left things a bit fuzzy and required some trimming for the joint to slide together.

And here are the two sides with the grooves cut.
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Once they are cut, you can just slide them together (with some suitable trimming where necessary).
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It's actually not too difficult in concept. Making good tight joints in a real project would take some careful work. I had some trouble with the small tenons chipping out at the ends in this soft poplar, and I don't have a very good fit at the miter in particular, but I wan't being very careful about it in this sample.

Give it a try!

[Nicholas Lingg]

Good work :) Looks Great. Now how do you put the 4th corner together?:confused:

[Ryan Baker]

Good question Nicholas. That would be a problem.

I suppose that if the bevel angle wasn't too much, and there was some slop in the joints, you might be able to get it together, but that doesn't seem like a good plan.

[Nicholas Lingg]

You know sometimes it just takes awhile for the light bulb to come on. ALL four corner will have to slide together at the same time.

[Ryan Baker]

Yes, I guess you are right. Not easy. But that would also help keep it from coming apart too ... which makes it a good joint for this type of box. Now for an extra challenge, try to assemble this with a bottom that fits into grooves in the sides!