I made this one without a plan, but most of these jigs use a similar design. This one is used for picture frames, so the backer board is movable. There are two bars that run in the miter slots. The movable backing allows fine placement of the spline in the corner of the frame, which is usually no more then 1 1/2 inch so precise placement is nice. The large backer makes it easy to clamp the frame in place. On my router table, I would alter this so the miter bars ran in the table's miter slots and the center of the jig lined up with the bit. This jig is made of 3/4 ply for the base, but the sliding part is 1/2 Baltic Birch.
How I'd modify this design for a router table: I'd make the base out of half inch ply set at the same 90 degree angle. But I'd cut out the center of the sled so I could drop in some 1/4 ply or mdf. This because you will have to change the bits and might even use a dovetail bit, so the replacable 1/4 inch piece acts as a zero clearance, anti-tearout piece.
I've seen numerous jig designs like this one. The most important thing to me was using an accurate draftsman's triangle to check angles. To make the V shape in the base, I simply set the saw to a precise 45 degrees, cut the 3/4 I used in half and applied glue while holding the triangle in place. Once the glue set it was perfect. There are two support pieces under the 45s that were cut the same way (Thank the lord for Wixey digital angle gauges). I used the triangle to work out the placement of the support pieces. So all the perfect 45 degree cuts support each other.
I cut a dado in the back part of the V for a Tslot and installed a T Track so I can easily lock down the vertical support. Make sure you cut all the parts with your saw set at exactly 90 degrees so it assembles sauare (Wixey again). You can see the slot where the blade goes throuh, that's where I'd cut out a wider opening for use on a router table.
It took several hours to figure out and then make this jig. It is solid and has a shelf set aside where it lives between uses.
The more I do, the less I accomplish.
Last edited by DesertRatTom; 03-27-2018 at 10:40 AM.