Ploughing Web Frame Dado

[Charles Brown]

Surely I'm over-thinking this.

Previously, when I made a chest of drawers I would use web frames that were 3/4" thick. I would use a 3/4" pattern bit and a small block to plough the dados and then come back with a dovetail bit fit in a guide bush to create a sliding dovetail. I've decided to change the size of my web frames and have run into a road block.

I would like to use a 13/16" thick web frame. This means I can't use the pattern bit. I would like to run this in one pass so there aren't a lot of fussy setups. I use a circular router base plate and do not think that guiding one edge along a straight edge is accurate enough. Should I create a jig that traps the base plate on both sides and then plough the dado? Is there a simpler way? I would like the setup to be straight forward and repeatable without a lot of fussy measurements (wouldn't we all?).

Maybe I answered my own question? Anyone have any other suggestions to help me through this little thought experiment?

How does everyone else create sliding dovetails with a shoulder in their casework?

[Mike Henderson]

I made a jig that consisted of two boards, the spacing of which gave me the dado width I wanted, with my chosen straight bit (a spiral bit). I referenced off the base of the router - this can be a problem so you want to keep your measured sides to the boards and not spin the router around (by "measured sides" I mean the distance between the router bit and the side of the router base - check each side so you don't have to spin the router around to cut the sides).

Mike

[Sam Murdoch]

As Mike says - also good idea to mark your feed orientation and stick to that - left is left and right is right. And make sure that you have a piece on the underside of your jig, on the outfeed end that is snugged up hard to your stock to keep your end cut from blowing out.

[Charles Brown]

I'm with you on keeping your router orientation the same. I'm not too concerned about blow out. With the way I build, if the backside blows out a little nobody is going to notice because of the rabbeted back.

Maybe I need to look into guide bushes? Does anyone know about guide bushes with an ID larger than 13/16" ? I know they don't come in the regular set.