Router Jig Mortising Question

[Bruce Miller]

I built a jig for my plunge router to do mortises.  Found  the design in FWW. My problem is the router rides on a 3/4" piece of plywood and the work piece clamps below it.  So in order to reach the work piece and then the depth of the mortise I have to pull the router bit out of the collett further than I usually do in other applications. How much of the shank needs to be in the collett?  I don't want the bit to wobble, or come out and tear up the work, the jig or me. Thanks for advise. Bruce

[Eric Johnson]

There has been a lot of conversation regarding this in the past. A search of this group should give a several different perspectives. I try to keep at minimum 2/3 of the shank in the collet for several of my jigs. I have several jigs of this nature so over time I have bought proper bit length to match the intended job and recommend doing the same.

EJ

[Preston Andreas]

Somewhere I read a minimum of 1". I use a router jig where the workpiece clamps even with the router. It is very simple and works well. You might try another type of jig. BTW, I also own a Powermatic mortiser and since I tried the router mortising jig, the Powermatic doesn't get near as much use.