box joints a little off register

[Brian Runau]

Did my first box joints yesterday. I cut all the sides and then used 1 side for the spacer and did the top & bottoms. Think this screwed me up the last 3 tops & bottoms we off.

I was doing pieces for four serving trays.

I think I need to literally do them as sets and pairs. Can't do as seperate pieces and then reassemble?

Thanks.

Brian

[glenn bradley]

You don't mention how you were doing them. When you say you used one side for a spacer, do you mean you cut the first notch and then used this as an offset? This is what I do with a sac-fence on one of my sleds and it seems to do OK.

The problem with using a key (as I do) is that a small error becomes compounded as you go along. I find a light but firm touch when registering the material against the key works best for me as opposed to a death-grip that can induce flexing. I seem to be able to make them OK after some practice.

Another idea might be to cut your fingers on over-width pieces and then rip them to width as required.

[Brian Runau]

I am doing them on a router with a sled.

[Joe Scharle]

Without a doubt 'creep' is very frustrating.
Mic the fingers and the slots. They have to be the same. Some folks like their fingers a thou or 2 skinnier, but I get snug joints with both the same.
What happens is:
a. the slot is FIXED...the cutter will always cut the same width slot. BUT-
b, The spacing of the index pin AND the width of the index pin COMBINED with superman force against the jig all accumulate into a progressive error.

And like Glenn, I trim an edge after cutting the fingers for best looking joints. Only talking a sixteenth at most.

[Michael MacDonald]

Norm Abrams did a NYW episode where he cut the drawer front and side as a pair. Don't quite remember which episode... if it will help, I can try to hunt it down for you. I did some recently and cut them separately. Luckily, it worked out for me, but I think there is a lot of sense in cutting the two joined panels together. Next time I do it, I will take that approach.

[Brian Runau]

Is there any way to correct the ones that are a bit off register, or since I have the flexibility, would I be better off to cut off the ends and redo?

Thanks to all.

Brian

[Myk Rian]

To me, there are 2 ways to create good box joints. With the Oak Park router table jigs, or an Incra jig.
http://us.oak-park.com/catalogue.html?list=boxj--
http://www.amazon.com/Incra-Fence-Block-Fixture-Package/dp/B001DT14H0

[Jim Terrill]

I have never used this, but the price is right if you don't want to make one on your own.
http://www.rockler.com/product.cfm?page=21338&filter=box%20joint

[Greg Peterson]

I just made my box joint jig and made a box. There was a little bit sliver of wood left, less than 1/32". Easy enough of an adjustment. I use the miter gauge with a tall fence with index pin. One thing I did after making the first box was I glued some 100 grit sandpaper to the front side of the jig just to keep them nice and snug.

[Peter Quinn]

I think its pretty tough to correct box joints once things have gone wrong. I'd cut the ends off and go a bit shorter. My index pin is SNUG. I usually cut the second pair using one piece from the first pair to reference all the cuts. I've never paired them up so to speak. Its not usually a problem if the widths are the same on all parts. A clamp holds my parts to the sled (TS set up), I don't trust hand pressure for safety and accuracy.

[Rick Frye]

I made one of these several years ago. It is extremely accurate. You can even cut box joints without a dado blade, or create varying spacing. Just do an internet search on "Lynn Sabin's basic box joint jig"

[Larry LaRoque]

+ 1 on using clamps, in fact Incra suggest using wood turn-screw clamps as they hold better.

[Lee Schierer]

I always cut my box joints in pairs. I offset the two pieces by the width of the pin then clamp the two sides that will mate together and cut the joints in both pieces at the same time. Even if there are errors, this will generally allow the pieces to fit.