Lock Mitered Closed Box Test

[charlie b]

Bay Area Dave's question about using a lock miter joint on a sloping sides letter tray got me to do some testing to see if it'd work. A post asking if a lock miter bit could produce a closed box - for a miter saw station ironically - was subsequently asked.

Did up some drawings to work out how it might be done and posted that stuff to a.b.p.w.. This evening I cut the parts for a test box per the drawings and routed the lock mitered edges of all the parts.

Did a dry fit and it worked. Problem then was getting a closed box with all mitered corners apart. Fortunately, the router bit set up wasn't perfect and I hadn't firmly pressed one of the parts down completely. A dental tool and some careful use of it got the box apart. Seems strong enough, even without glue. With glue it should hold together really well.

Have posted an image of the test box with edge details in a.b.p.w. if anyone's interested.

charlie b

[Eric Johnson]

Particularly if you wrap it up with some good ol fashioned filament tape!

A bit of Titebond II, and the ultimate gift box, for someone you don't specially care for. Hehehehe

JOAT It's what you learn after you know it all that counts.

- Pete Maccarrone

Life just ain't life without good music. - JOAT Web Page Update 29 Jan 2004. Some tunes I like.

[Steve Turner]

Pretty cool, eh? I've used lock miters on plywood for several of my projects, and you may remember me posting pictures of some five-sided boxes (open on the top end) on a.b.p.w a year or so ago. The one's I've made are about 1' square, and I use them all over the shop for holding cutoffs, jigs, etc. My wife and friends have a few, and I've got friends and family after me to make more. :-)

I've built some drawers using lock-mitered baltic birch panels for the front, back, and sides, but I've yet to build any with lock-mitered bottoms. I think that would be very nice (and sturdy!), but you wouldn't be able to use the bottom-mounted drawer rails that tuck up under the side panels.

I should have warned you about that :-)

Definitely. If you're doing a closed box like this and you want the inside to look nice (after you saw it apart, of course) you might consider using some fairly wide (and carefully placed) blue masking tape to protect the inner panels from glue squeeze-out.

[charlie b]

Thanks for the blue tape tip. Getting dried squeezed out glue off is not fun. Getting out of a corner is less fun. Getting it out of the corner of a very small box requires dental tools - and valium.

Hadn't though about using the joint for 6 or 8 sided things. Will it work for odd number of faces "boxes"?

thanks

charlie b

[Eric Scantlebury]

Thanks for the info Charlie.

Eric

[Bannerstone]

Snip

Seems almost airtight, possibly you could use air pressure to blow it back apart during dry fitting or even do your final clamp up with a vaccum setup.

Anyway thanks for the post, it was great food for thought. Now I really want a lock miter bit. :)

David

[Lawrence Wasserman]

[Steve Turner]

Been there, got the T-shirt, etc...

Don't know about that, but when I spoke of a "five-sided" box, I meant a regular box with four sides and a bottom.

I'm currently punishing my brain trying to figure out how a person could use lock miter joints to connect panels of differing sizes so that the inner and outer surfaces mate cleanly (for example, 3/4" side panels to a 1/2" back). This means the miter angle would no longer be 45 degrees, so I doubt that this would be doable with our regular router bits. You could build a jig to run the panels through at angles other than 0 and

90 degrees, but the "lock" portion of the joint would then be out of sync with the miter angle and would probably make it impossible to join the panels together.

Probably a job for the table saw, or a different joint altogether.

[Bridger]

it should be doable. you'd use the same bit on both parts, but run them through at different bevel angles.

[charlie b]

Have posted one way to do what I think you've got in mind to a.b.p.w. Shouldn't be that hard - IF - the half inch stock is the one cut flat/horizontally. You just need a piece of 1/4" under the 1/2" and set the bit height and the fence for the 3/4" stock.

And this one's the last lock miter wild hair idea I'm gonna do! (unless someone comes up with a really interesting potential application :) ).

charlie b

[Steve Turner]

Saw your diagram; reply on a.b.p.w. Thanks.