Monday, November 16, 2009

A Better Mousetrap?

When I built the original pistol case I knew that being accurate on the finger joints was important.  I  thought  that I had discovered a good jig on the web but after building it and trying to make it work found it just wasn't so!  The jig here came from a publication from ShopNotes called: Table Saw, best tips, tools, and techniques.  What made it a better jig is that the two sides ride in the miter gauge slots and have 2 pieces of 3/4" ply keeping them square.  The only negative I had is that it wanted to tip forward when cutting fingers on a long board but that was easy enough to overcome by placing my forearm on the rear portion of the jig.  It has a jig fence and what I'd call the finger fence.  You need to make this "finger fence" for each size of finger joint you plan to make, I only made this for the 3/8" size I'm using on the pistol cases.  A really nice feature is the that board you're cutting rides on a 1/4" piece of mdf, this prevents it from moving up/down in case your blade insert isn't perfectly flush with the table.  There's also a sacrificial piece of mdf on the back to help prevent tear out.  The adjustment comes from having a larger hole on the part that slides in the miter slots than the carriage that goes through the finger fence.  In my case, I had a 3/8" bolt so I used a 1/2" hole in the rear fence.  The adjustment is done through the piece on the end with the three holes in it.  This is attached to the rear fence, the single hole at the front is so that you can place a screwdriver in it to adjust the position.  I put a tee nut there (10/32) and used a cabinet handle screw to accomplish this.  Once you've dialed in the cut simply tighten the wing nuts on the back of the jig.
     One last thing I'd like to share, if you've ever made a finger jointed box with a panel floating in a dado/groove you know you can't cut that dado all the way through the finger.  What's required is some chisel work to stop the cut.  I used my test pieces from setting up  the finger joints to support the sides of the piece as I cut the stopped dado.  Of course, you could also use your router to cut that and not have much to square off but who wants to take the time to set that all up and then listen to the racket!  I used a dado blade in the saw and needed to square off the ends of the dado.

No comments:

Post a Comment