Jigs on the Table

The blocks for the legs are now complete.  Rough glueup size is 1 3/4″ x 2″. The blocks have to be brought square and milled to final size (1 5/8″ x 1 7/8″). The procedure is the same as for squaring the lumber: square two adjacent sides on the jointer, then plane the other two flat.  After that, the legs are cut to their rough length.

Now on to two simple jigs, that will make the whole project proceed more smoothly.

The Angle Jig

A lot of cuts for this project are at an angle – about 3 1/2 degrees.  This includes the side rails, the drawer front, and the ends of the legs.  They don’t have to be exactly 3 1/2 degrees, but they do all have to be the same.

Trying to measure an angle like that repeatedly and accurately is a virtual impossibility in this kind of work. But it’s simple to cut a layout jig to mark the pieces and guide the cuts.

The jig is a simple t-shaped block, made out of two pieces of 3/4″ plywood.  They’re glued together and tacked with a pin nailer into a t-section about 8″ long. Then, the jig is laid on the miter saw, and the saw set to 3 1/2″.  The center rail of the jig is supported on a block so it doesn’t shift. First one end of the jig is cut off, then the piece is flipped and the other end cut at the same setting.  That ensures that both ends of the jig are cut to the same angle. The two blocks are aligned in miter clamps (see photo) to keep them square during glueup.

Once built, always double-check the accuracy of a jig – remember, any errors in it will transfer to the project every time it’s used. In this case, the easiest way to check is to use one end of the jig to mark a line on a board, flip the jig to the other end, and mark another line adjacent to it. If both ends of the jig are the same, the lines should be parallel.  This one seems fine, and this jig will be used to mark and lay out every cut made at this angle through the project. The angle of the jig is written on the side – jigs never get thrown away, they go into storage in case I make another piece of the same furniture sometime (that’s a lesson learned the hard way).

The Dovetail Jig

I’ve had a couple of problems laying out dovetails. One is that I tend to overcut the layout lines slightly, and the other is in aligning the blocks to mark out the tails.  The blocks tend to slip around when marking, which can make the lines inaccurate.  And yes, I cut pins first – otherwise, I find it difficult to follow the line for the pins across the endgrain of the pin board. That’s a loooong argument, and there’s enough on the internet written about it to fill several books.

I think one simple alignment jig may solve both problems. The jig is two small blocks of rock maple out of the scrap bucket, about 6″ long. Holes are drilled in both ends with a 3/8″ forstner bit.  Drilling is done with each piece clamped against the fence of the drill press, to keep the holes in the same locations.  Then a 1/4″ threaded sleeve is hammered into the holes on one block, and two pieces of 1/4″ threaded rod is added.  Nuts are screwed onto the rods and tightened against the backplate, and a couple of drops of superglue are added to each to lock the nuts in place.  Then the other block is placed on the rods, and threaded knobs screwed on.

That’s a fancy way to say “the two blocks make a little sandwich that you can tighten around the workpiece”.  The blocks are slipped over the workpiece (it’ll handle pieces up to about 3/4″ thick”, aligned with the layout lines, and tightened down.  When the cuts for the pins are made, the saw will hit the stop when it reaches the layout lines.

It will also allow me to brace the tail board against the pin board for marking out the tails, without having it slip around. Of course, the jig will eventually get scarred up, but it’s just a piece of scrap wood and about a dollar’s worth of hardware, and only took about 10 minutes to make. And if it saves me overcutting the dovetails on this project, then it was 10 minutes well spent.

Next: More project pieces, more work on the top, and (maybe) beginning joinery.

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One comment on “Jigs on the Table

  1. Nice dovetail sandwich jig, Ross! And nothing wrong with cutting pins first. I do that, too, if I need to make really fine dovetails.

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