dado minus the chippers...

[sloughin]

I've been reading Jim Tolpin's book "Tablesaw Magic" and have built a number of his jigs and fixtures for my TS3650.

One thing he describes is how he cuts the cheeks of a tenon using the two outside dado blades, minus the chippers, separated by "a plywood spacer." The pair of blades can then be used to cut both cheeks of the tenon at the same time, giving a very repeatable thickness assuming you get the plywood thickness just right. My dado set has a few spacer shims but nothing like the 3/8" I would need for this kind of application.

Also, I'm a little nervous about putting a plywood spacer in there. If it comes apart at full speed, I could ruin my saw or have a chunk of plywood hit me in the face.

Has anyone else tried this technique? I was thinking about using back to back stabilizers (like the CMT set). I'll need about a 3/8 spacer for the project I'm working on right now, and even back to back stabilizers won't give me 3/8".

[nelz]

sloughin ,since you dont seem comfortable with the spacers I would try makin your own tennoning jig,i made one from shopnotes issue#6 which works really well
It took a bit to build but makes it all worth while as you use your OWN handmade tool

Nelz

[wbrooks]

I don't think that plywood will fly apart even if it cracks the pressure of the blades and arbor nut should keep it together. That said if a tool scares you you should find an alternate method that you have confidence in. You could make an indestructible spacer out of UHMW or Lexan.

[sloughin]

Thanks for your replies. I've actually already made Jim Tolpin's tenoning jig which slides along my extended fence on a sled. It works just fine, though I was thinking about the spacer technique since it cuts both cheeks in one pass, and gives you more precise control over the thickness of the finished tenon. At this point, I got a quote for $61 for a set of metal spacers (11 1/8" spacers and then an assortment of sizes down to 0.001" (which of course would be overkill).) I'm also talking to my brother, who has a metal working lathe, about making up spacers in brass. Since I always cut the tenons to fit mortises I've made either with my chisels or with a 1/4" router bit, I don't need too many. UMHW is a good alternative too, and I could machine that on his lathe.