Shelf Pin Jig

A clever shelf pin jig. Use a plunge router for straight evenly spaced shelf pin holes.

I have one of those plastic shelf pin jigs that you use the spring loaded drill bit to drill a quarter inch hole for the pin. The problem with that system is I'm not dead on with keeping my drill perfectly vertical when I drill. So last night an idea came to me. A while back, Woodcraft had the Trend plunge router on sale for $99. It came with one guide bushing. You could probably get other brands to fit, but rather than adapt to adapt again, I used what was already there. The outside diameter of their guide bushing is 3 quarters. Seems strange I know, since you only need a quarter inch router bit to make the holes.

Here's how I made mine. I took a 4 inch wide piece of quarter inch thick UHMW to use for the jig.

I ripped a piece of peg board so that a row of holes would run down the center of the jig. Next I fastened the peg board using double sided tape. I wanted to use a Forstner bit to drill a hole that would be the same size as the outside diameter of the guide bushing. Forstner bits have that tiny little point in the center so you can't drill a quarter inch pilot hole using a quarter inch drill bit that would fit the peg board holes. That's when the idea hit me. Or maybe it was something else that hit me, but about that time an idea came to me too. I have a set of dowel marking pins. The quarter inch version is Woodcraft part number 123717. This is a piece of steel with a quarter inch shoulder and then a fairly sharp point on the end. I took the marker, set it in the hole of the peg board with the point down. Then my favorite part, smack it with a hammer to make a reference point for the Forstner bit. I made 15 holes but only drilled 14 of them to full size. Next I convinced the peg board and double sided tape to come off of the jig. I took the jig to the drill press, lined the spur of the Forstner bit up in the dimple the marker left and drilled all the way through. I only drilled a quarter inch hole in the extra hole I had marked. This is for alignment if I want to go all the way down the side of a cabinet or bookcase. Just drop a quarter inch pin into that hole and into a hole already drilled on the upright and the spacing stays consistent.

To finish the large holes off, I took a large counter sink bit and beveled the edges of the holes. Makes it easier to drop the guide bushing in place.

I set the guide on the upright and used spring clamps to hold it in place. The spring clamps are strong enough to hold it in place without leaving a C clamp mark on the wood. It works great and I can drill a bunch of holes fast now, and using a plunge router I don't have to question myself. I know the holes will be perfectly straight. Submitted by Bob Kenedy