Machining the Base

The design of the pivot for this compound was inspired by the pivot found on Southbend 9 inch lathes. It has the advantage of being able to adjust the angle of the compound without loosening all 4 bolts of the compound (one of which is often under a part of the compound).

The first step is to chuck up the piece in the lathe and face one surface.

The next step is to face the other side. Then cut it down till it is 0.625 inches thick.

The next step is to take cleanup cuts on the four edges.

Here I am using an adjustable boring head to bore the pivot base for the compound pivot.  Then the edges are machined sequentially keeping the hole centered until a 4 inch square is attained.

Mount the base plate on a rotary table. Then drill the holes for the pivot clamping pins. Drill the center hole that goes towards the headstock first.

Rotate the plate 120 degrees and spot face a location for drilling the hole.

Using a center drill, start the hole for the clamping pin.

Then drill the hole through into the pivot hole using 1/4 inch drill.

Then using a letter F bit, step drill the first half inch of the hole for a 5/16x18 tap.
Last Modified 12/14/06 09:27