Angled End Half Lap Joints

jim crockett

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120
Location
Jay, Maine
I am building a folding wall-mounted table for my shop. The braces are 2x4's, 24" horizontal and 30" vertical. The plans call for half lap joints at all corners. I would use the table saw if I had a half decent dado set, but I don't, so I thought I would use my router with a 3/4" straight bit. The problem I ran into was that the angled joint is so long that the router has no support when routing the end of the half lap. As long as I have support, I can get a reasonably smooth surface but as I get to the end of the supporting material, the router bit dips in and gouges a divot in the wood. I tried using a second 2x4 for support but still similar problems especially when transferring the support from the 2x4 being cut to the auxiliary piece.

Ideally I'd love to cut these on the router table but haven't figured out how to cut a 51.3 & 38.7 degree angles on the table. There must be some kind of a jig I can create for this - maybe something like a surfacing jig only at an angle - but I haven't come up with a good idea yet.

Anyone have an idea of how I can accomplish this task? Jigs? Or maybe I just need to make an auxiliary base plate that is larger? Any suggestions will be appreciated.

Thanks.

Jim
 
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That joint is just made to be cut on the radial arm saw. Leave your saw a touch high so you can clean up your bottoms nice and flat with a chisel or shoulder plane, and then cut your angle.

If you don't have a radial arm saw, you could easily cut them by hand too. Just use a good crosscut saw to and rip saw to make the notch, then make the ankle cut with a crosscut saw or miterbox.

My preference is the radial arm saw though. Many people believe its use is outdated, but to understand it, is to love it.
 
Will a TS blade reach if you stand the 2x4 up on end at the 2 different angles? I'm thinking a TS tenoning jig then 2nd miter cut if the tenoning jig cut will reach.
 
I don't know if I can visualize the actual angled joint but my suggestion would be to cut the angled shoulder like you are doing and then finish cleaning up the ends that give you trouble on the router table.

Hope that makes some sense.

Keith
 
Angled Half Lap Joint

Will a TS blade reach if you stand the 2x4 up on end at the 2 different angles? I'm thinking a TS tenoning jig then 2nd miter cut if the tenoning jig cut will reach.

Unfortunately, no - the lap edge needs to be at least 3-1/2" back from the edge and my ts blade only extends 3" + a little. I suppose I could finish the remainder with a hand saw, though.

Jim
 
Just to let everyone know, I finished up the angled half laps with my *&#($*& Dado Blade set. Then sanded down the ridges! Fold-down work table is almost complete - just need to get some PB for the top and then cover with hardboard. Nothing fancy, but I have very little room and this will give me a worktable that's somewhat out of the way.
 
Ideally I'd love to cut these on the router table but haven't figured out how to cut a 51.3 & 38.7 degree angles on the table.

I'll take it from this statement that you do not have a miter slot on your RT. Yeah, I know, lotsa folks don't know why you'd want one. Well, here's a reason. Going on that assumption, I would make an angled backer board (or two or three) and ride the fence:

Untitled-2.jpg

If your cut will not tolerate the fence, add a guide to your backer board to ride the front of the table:

Untitled-1.jpg

On either of these cuts, clamp the board to the backer to maintain control. This may not be right on base but maybe the ideas will help. Wait a minute . . . what a dork, I missed your post that you were already done. Sorry about that.
 
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Just leave the piece long as you cut the laps with the router, and trim to length after. Or doublestick tape an offcut to the bottom of the router to support it on the work surface as you cut.
 
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