DIY Lap Joint Jig (for any size stock)

I really like the Bridge City Kerf-Master jig, but have been wanting to build an open-grid top table for solar panel assembly with 2x lumber, which is beyond the capabilities of the KM-1.

I've worked up a one-piece jig that's only suitable for use with the blade you use to make it, but that doesn't bother me much. It should work for anything from coffee stirrers to whatever your saw can handle.

No measurements are needed to make the jig, and only one measurement is needed (to locate either edge of the joint) during use.

During use, you'll need a small scrap of the stock that's to fit into the part you're cutting. In the drawing, I've labeled it "Crosspiece Sample".

I'll leave the graphic on my web site for a week for criticism and comment, and then either discard it or replace it with a web page with larger graphics if feedback indicates I should.

You can see the drawings at:

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green block is a miter fence stop, and red is used to show cuts - please let me know if it's confusing)

Reply to
Morris Dovey
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Thanks from a mostly lurker, Morris. I'll have to study it and think about it for a while, to see if I understand it!

Matt

Reply to
Matt

Interesting. How about holding the pieces together with embedded magnets? Or maybe a spring-loaded arrangement - pull it apart, twist to adjust, then the spring pulls it back together on the new setting.

R
Reply to
RicodJour

Sheesh! I give you a one-piece precision jig that you can whip together in under three minutes from whatever scrap you might have lying around and you tell me that what you want is springs and magnets...

You're a tough customer to please! :-D

No. No magnets. No springs. No moving parts. Not even yellow paint.

(But I'm curious to see what you'd build with that extra hardware)

Reply to
Morris Dovey

Well, it seems to me if you're going to be putting in the time, make it with a few standard pieces for your favorite size joints, and then just plug and play. Color code the pieces, mass produce, buy an island. Pretty straightforward, really. ;)

R
Reply to
RicodJour

Morris Dovey wrote in news:hddd7b$v18$ snipped-for-privacy@aioe.org:

I guess I need handholding while this jig is made and a demo of its use. Too much of a newbie at jigs to understand, sorry Morris!

Reply to
Han

No reason to be sorry about anything. Do you have some scrap to play with (say a foot-long piece of 1x4)? I'll walk you through making the jig and cutting the first half of the first joint...

Reply to
Morris Dovey

Neat setup. It relies on a stop block at the end though, which could get tricky if you need to deal with long pieces. Also if you're doing multiple half-laps on a single board you need to relocate the stop block each time, which isn't as convenient for doing a grid like you're talking about.

If you were dealing with pieces too long for a stop block, you could combind it with a finger-joint jig, where the "finger" in the jig is the width of the blade and placed at the desired grid spacing. Then you use your jig to do the initial half-lap on each board, and the finger-joint jig to do all the others at equal spacing.

Chris

Reply to
Chris Friesen

It /would/ be a hassle on the TS - but my RAS setup allows me to locate as many fixed stop blocks as I want along a 12' length. There is a pair of early photos at the bottom of

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the only hassle would be in setting up the first board in each direction - but after that was done, I wouldn't even need to measure.

There /have/ been times when I've wanted a 12' miter fence, too. :)

Sounds like it'd work.

Reply to
Morris Dovey

You're welcome. I just returned from trying it out for the first time in the shop, and can report that I got a joint that fit exactly. It took a fuzz under three minutes to make the jig, and about the same to make the joint itself.

Reply to
Morris Dovey

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