Jigs and Rigs for Cutting Tenons

Thoughts on how to set up for cutting tenons on a table saw or other equipment. January 20, 2010

I just purchased a General tenoning jig for the first time. It seems to me like it's very sloppy when you adjust the different settings on the jig. Is this common with these jigs, or should I return it for a new jig? I would think it should be somewhat stable in order to get accurate tenons.

Forum Responses
(Architectural Woodworking Forum)
From contributor T:
If it's like mine, it has a few adjusting screws. They are designed to make it fit the saw snugly and to take out any slop that you have when you first take it out of the box. I enjoy mine - after some fine tuning.

From contributor R:
Do yourself a favor and return it for a refund. The money would be better used for something more useful, a RonCo salad straightener maybe.

All joking aside, I cannot think of a more useless device, unless you are a novice and do not know how to safely use a tablesaw. Tenons can be quickly and accurately cut by simply using the saw fence and a zero clearance plate. An auxiliary (tall) fence may be clamped on for particularly deep cuts but normally is not needed.

From contributor J:
I don't know how contributor R is cutting his tenons (freehand?), but before I recently switched to loose tenon construction, I used a Delta tenoning jig which was adequate for the task. There is some slop in these devices (hey, what do you want for what they cost?). But for the most part you can tune them in enough to get your tenons milled accurately.

From contributor A:
Either ShopNotes or WoodSmith magazine had plans for a really good tenoning jig a few years back. Issue #187 if memory serves. Has presets on it to cut 1/4, 3/8, and 1/2 inch tenons. It is very good and fast at offset tenons. See if you can find that back issue and build one. Took me about 2 hours, and worked like a charm until I left it behind during a move.

From contributor M:
We still do our tenons on an older Delta jig. It's cast iron and a dream to work with. The extra weight gives it the "dream" - no slop whatsoever. If you can find one in good shape, do yourself a favor and grab it. I've seen them usually go for $350 or better. There is a good reason for this - if you have the chance to use one you will understand!

From Gary Katz, forum technical advisor:
I always have a tall auxiliary fence mounted to my rip fence, so it's easy to use a homemade jig, like the one in this picture.

Click here for higher quality, full size image

From contributor R:
And I thought Rube Goldberg was dead...

From Gary Katz, forum technical advisor:
Oh no... not at all. He doesn't even smell dead.

From contributor R:
In answer to the question regarding how I cut them, I do it the same way I do most of my work on the table saw - I use the fence. I do not consider this freehand as the fence provides plenty of support. Simply stand the piece on end, and the right hand powers it through the cut and the left provides pressure (control) on the outside face to keep it fenced and vertical. Obviously a zero clearance plate is required for this operation, as the stock plate as shown in Gary's photo would present a hazard cutting in this manner. A tall fence, such as a 6" wide piece of plywood, can be quickly clamped to the stock fence if you feel more vertical support is needed. Work from a reference "face" for accuracy cutting offset tenons or if your tenons are centered and the stock varies in thickness slightly. Set the blade height for the tenon length and set the fence to the outside of the blade to define the inside face of the tenon to be cut.

Make the first vertical cut. If you are cutting centered and all your stock is the same thickness, you can flip the board around to fence the other face and make the second cut, otherwise reset the fence to the inside of the blade to make the second cut. To cut the cheeks, set the blade height to the shoulder height and the fence to the tenon length, measuring to the outside of the blade, and run the end of the piece hard against the fence to complete the two cuts. Use the miter guide for safety for the crosscuts, particularly for narrow pieces. You can also readjust the blade height at this same setting to cut a shoulder to haunch the ends of the tenons if desired. I also had a few spacers made for my most common size tenons, to use with a matched pair of rip blades and shims to make the two vertical cuts in one pass; this also eliminates 1 set of the fence if working from a reference face.

There maybe some rare (very rare in my experience) occasions where a jig is called for; if the work piece is too small to be handled safely for instance, but even in this event a shop built fixture can be quickly and cheaply cobbled together, not to mention designed or targeted for a specific task such as the jig shown again in Gary’s photo, however, it looks like he is not cutting a tenon but beveling the end to a feather edge. This is a good example of where a shop built jig is advisable as this could be a bit dicey even with a tight clearance at the blade and plate.

I have no argument with the manufactured jigs for the novice or inexperienced, but why waste money on what others have pointed out is a typically substandard tool as available today? The antique Rockwell is a beautiful tool but, again, what’s the point when 99% of these operations can be done quickly and accurately without it.

From contributor C:
I do a fair amount of tenons and I find a combination of my 20" bandsaw, radial arm saw and stops to be fast and accurate.

From Gary Katz, forum technical advisor:
I have a little bandsaw that can't cut straight and wish I had a bigger one. That's my next goal. I can imagine how easy it is to make even large tennons using a bandsaw.

From contributor H:
I've cut thousands of tenons and use a good router table with a large straight bit with a fence. Very accurate, micro adjustments a snap, all cuts - including shoulder cuts - made without re-adjusting. Easy tricks employed to avoid blowouts. Long pieces may require a tenon buddy to hold the off end.

From contributor S:
Another method, if you have a shaper, is to use a rabbeting knife and a coping sled. Unless you need extra long tenons, this works very well, and is super fast and accurate.