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Jan Bianchi
05-03-2015, 8:00 PM
My question is whether this jig is a safe way to cut the pins of a large dovetail, and if not, if anyone can suggest a different way. I am making a large live-edge slab coffee table. The wide slab legs will be connected to the two long stretchers by a large dovetail joint (a la Hank Gilpin's joinery in the current Fine Woodworking). Because the dovetails will be 3 1/2" tall and 2" inches wide, I am not confident that I can cut them accurately enough by hand. I can cut the tails on the band saw, but not the pins because the slabs are too wide to flip inside the throat of my band saw. (See pictures of poplar mock up--not the actual table top, and the actual slab legs below.) I am thinking of trying Greg Paolini’s method demonstrated in Fine Woodworking http://www.finewoodworking.com/how-to/article/how-to-cut-dovetails-on-the-tablesaw.aspx (http://www.finewoodworking.com/how-to/article/how-to-cut-dovetails-on-the-tablesaw.aspx) 312854312855He marks the location of the pins, sets the table saw’s miter gauge to the same angle as the tails and attaches a tall wide fence with a foot for the pin board to rest against and slides the whole fence into the cut. However, I am concerned that these pin board slabs are large and unwieldy, even if I make the fence much taller than what is demonstrated. If you don't think this is safe, can you suggest a safer way?

Kent A Bathurst
05-03-2015, 8:27 PM
Get some other material of the right size, and use it to practice cutting by hand.

rip off the first practice set, and try again.

Rinse. Repeat.

3 practice runs, and you will be able to do it by hand just fine.

Hold vertical on a TS? Maybe. Not me, though.

Rich Enders
05-03-2015, 8:56 PM
I agree with Kent. The attached photo's show 1.75 inch dovetails in maple which were the first ones I ever cut by hand. I used a Japanese pull saw from Tashiro.

They didn't have to be perfect on a workbench and that took some of the pressure off.312866312867

Jan Bianchi
05-03-2015, 9:17 PM
I've hand cut quite a number of small ones, but four inches is a little intimidating. I glued up the poplar legs so I could practice, practice, practice. Might as well practice by hand. I think you both confirmed my discomfort with the jig. Thanks.

Bruce Wrenn
05-03-2015, 9:21 PM
Why not build a sled for your dovetails. Flat sheet on bottom, with a TALL fence centered over width of sled. Sled has two runners to fit miter slots. Bracing attached to sled from tall fence. Cut a couple of clamp slots in fence to hold slab in place.

glenn bradley
05-04-2015, 8:17 AM
We all have a papa-november-romeo when performing woodworking operations. I cut finger joints on the tablesaw on some pretty big drawer fronts but, I would take the cutter to the work if things got any larger/heavier. By hand or with a router to hog out the bulk of the waste, I would bring the tool to the work in your situation.

Jamie Buxton
05-04-2015, 11:01 AM
You're not telling us the size of the slab. From your second pic, the slab might be only 20" tall. If that's true, you could likely run it through the table saw if it is properly fastened to a jig that holds it upright and at the correct angle. But you also say "large coffee table", which might be 40" or more tall. At that size, bringing the tool to the slab makes more sense. You might consider a router jig -- something like the pin side of a Keller jig. The router sits essentially on the end of the slab. You could put a top bearing on a long straight bit, or you could use a template guide. I'd probably rough-cut the waste away before I use the jig to make the final edge cuts.

Mike Henderson
05-04-2015, 11:42 AM
If you mark both sides of the pins, you can saw safely to the waste side of the pin and then trim by hand (with a chisel). Since you have marks on both sides, trim to the marks and then use a rule to make sure you trimmed "flat".

Mike

Jan Bianchi
05-04-2015, 10:37 PM
This is what I eventually did today. The first one came out pretty good. None of my dovetail saws were wide enough to cut the pins 4 inches deep so I had to use my back saw to start the cut and then use a Japanese double sided saw to finish. Seemed to work pretty good. If I were going to do more than four of these though I would figure out a jig.

Jan Bianchi
05-04-2015, 10:55 PM
The finished leg will be 18 inches tall. I like your idea of using a template on the side of the slab, but the pins will be 4 inches deep. Do they even make a straight bit that long?

Jamie Buxton
05-04-2015, 11:33 PM
The finished leg will be 18 inches tall. I like your idea of using a template on the side of the slab, but the pins will be 4 inches deep. Do they even make a straight bit that long?

4"? Hmm. I've used an end mill that long when I needed to reach down to the bottom of a hole. But I wouldn't do this operation with a 4" long bit. This operation has you cutting along the side of the bit for the full 4" height. That's a lot. I'd go with the hand tools -- pull saw, and a chisel to pare to the line. It'll take a while, but that's pretty much what you're committed to.

Oh, and by the way, the usual 10" table saws only can cut 3" high. You couldn't do this operation with it.

Jan Bianchi
05-05-2015, 5:39 PM
Yes, I realized this too after spending all that time looking for an appropriate jig which is why I went for the hand cutting. I just finished the second one and it was pretty good too. But thanks for the encouragement.

Kent A Bathurst
05-05-2015, 5:57 PM
Occam's Razor wins again: The solution with the fewest assumptions will usually be the correct one.