|Project by Spencer||posted 02-23-2013 05:14 AM||4476 views||9 times favorited||5 comments|
Another router circle jig. I built this one to fit the plunge base of my router. The first picture shows the setup with the router base in the “base” of the jig. Last picture is the bottom side of that base showing bolts epoxyed through the hardboard and 3/4” ply to screw the jig knobs on to from the top.
Skip to third pic to see how the hardboard “arm” is sandwiched between the base ply and another piece of ply with a little bit of the hardboard arm extending over the router base to hold that side of the base in the jig. Between those two pieces of ply there is a dowel that the hardboard arm sits in to prevent slipping.
Second pic is the back hold down. Again, two pieces of ply, the bottom one glued to the hardboard base, the top one is clamped down with the jig knob. Two dowels keep the top piece in position.
Fourth pic is the trammel. Two pieces of ply simply squeeze the arm. Holds really well. Trimmed bolt epoxyed to the underside is the pivot pin, so this does require a hole in the workpiece. So far, this has not been a problem on my projects. Fifth pic is this same contraption opened up. Hinge on one side, jig knob on the other. You can see I trimmed one of the pieces of ply to fit the hardboard in there just right. If I need a longer trammel, all I need to do is cut a longer piece of hardboard.
The great part of this jig is there is no need to remove the baseplate of the router and screw it to something else – it just slides right in the jig as is, then simply tighten up the knobs. Super simple. Easy. Quick. I love tools like that.