Flowerpot
Apr-19-2004, 12:03am
I can't remember who had posted the top carving setup for the drill press, with the 20 threads per inch indexed depth guage, but I made my own 10 cent version of what they had done. It worked very well, so thanks for the hint!
Mine is a piece of wooden dowell self-tapped onto a bolt with 20 threads per inch. Each revolution gives 0.050" depth adjustment. The drill press stop stays fixed, and the dowell moves up and down to determine depth of cut. I should use a different drill bit, but I could not find a perfect one; grinding the spike off a wood bit did not work well, as the spruce tore away pretty badly, so a standard bit was better.
After "zeroing" the jig by a single test hole, the thing was accurate to within a couple of thousandths even over 0.25" throw. I drew contours of constant depth (relative to the underside of the top, which is still flat at this point), and went around drilling happily. The hand work is going quickly -- I like this setup, and it's good and cheap.
Mine is a piece of wooden dowell self-tapped onto a bolt with 20 threads per inch. Each revolution gives 0.050" depth adjustment. The drill press stop stays fixed, and the dowell moves up and down to determine depth of cut. I should use a different drill bit, but I could not find a perfect one; grinding the spike off a wood bit did not work well, as the spruce tore away pretty badly, so a standard bit was better.
After "zeroing" the jig by a single test hole, the thing was accurate to within a couple of thousandths even over 0.25" throw. I drew contours of constant depth (relative to the underside of the top, which is still flat at this point), and went around drilling happily. The hand work is going quickly -- I like this setup, and it's good and cheap.