compound tenon

[Robin Cruz]

this project is kicking my butt.

I have a compound tenon to make in a chair side stretcher. The tenon has a 4 degree angle from rear for back to front of chair (wider in front). the cheeks of the tennon have about a 4 degree slope to match the back of the chair.

I think I can do it as a compound cut on the table saw using a dado blade. the blade set to 4 degree and the miter set to 4. and using the miter slot on both sides of the blades to cut either side of the tenon. Then use a handsaw to cut the narrow cheeks and clean up the tenon cheeks with a chisel.

Any suggestion for easier approach?

[Jamie Buxton]

A different approach is to use a loose tenon. You crosscut the end of the rail where the shoulders are. (This is nice because it assures that all the shoulders are in a plane.) Then you cut a mortise in the end of the rail. I use a plunge router and and edge guide. I build a fixture which clamps to the rail and provides a plate for the plunge router to rest on, and has an edge for the edge guide to register on.

[Wilbur Pan]

If you are going to use a handsaw for the cheek cuts, why not use a handsaw for all of the cuts?

[Mike Henderson]

I use a tenon jig on the table saw to make those kind of tenons. The jigs are not that expensive - about $65 - and are really worth while if you make chairs very much.

If you get one, make a few complex tenons out of scrap first.

Mike

[Robin Cruz]

I use a tenon jig on the table saw to make those kind of tenons. The jigs are not that expensive - about $65 - and are really worth while if you make chairs very much.

If you get one, make a few complex tenons out of scrap first.

Mike

I see. So the jig will make all the angle adjusts and the blades stays at 90 degrees it appears from the picture. The Grizzly seems to do everything.

[Mike Henderson]

I see. So the jig will make all the angle adjusts and the blades stays at 90 degrees it appears from the picture. The Grizzly seems to do everything.
That's correct. I don't know the relative cost, but Rockler and Woodcraft sell the jigs also. They're pretty standard so unless you go with a real junk one, any one will do the job. It's good to have one in your shop, especially if you're going to make chairs.

Mike

[there's a few "tricks" about using it so when you get it and try your first couple of scrap cuts, post and people here can give advice.]

[Robin Cruz]

I just discovered that the tenon is straight but the mortise is at a 4 degree angle. only the tenon shoulders are angled. I guess that makes it easier. Its not a compound mortise anyway.

I wonder if the router approach would be better now. I have a table mounted Hitachi plunge router. I could remove it for this task of making mortise. Make a mdf platform for the mortise in the end of the boards. I have templates for the legs already to edge with the router and now I could put make them as router mortise guides as well.

[Mike Henderson]

Make a regular tenon then trim the shoulders with a chisel to the 4* angle. The outside and top of the joint will be the most visible so favor those sides (if there's a small gap or irregularity at the back and bottom, no one will notice).

Mike

[Vince Shriver]

Kind of spendy, but looks well made: www.mortisepal.com (http://www.mortisepal.com)

[Robin Cruz]

Yea i saw that. Im making a jig now to do try and do something like that.