Machining Fun

Machining Fun

I mentioned a couple of days back that I was struggling with machining a slightly complex part. The harsh reality is that machining this workpiece in a vertical position just doesn't work. Even very light cuts (.020") in Delrin seem to exceed the Sherline's mill vise grasping capabilities. The jaws only stand about 1" high, and the part that I am cutting is 3.42" tall. Okay, the cut is 1.5" tall, by .020" deep, and I am side milling. But it is already a slow enough process without having to make it even slower.

Because the workpiece is 2.62" wide, it won't fit in the Sherline mill vise lying down. One possibility is to buy a mill vise that is larger, so that I can lay the workpiece on its side, and do the cut that way.

As an experiment, I used the clamps that Sherline sells to lock the workpiece to the table, eliminating the mill vise completely. This works surprisingly well, once everything is clamped down securely. It takes a lot of passes, because I am using a 3/4" diameter end mill, but the good news is that I can take pretty aggressive cuts--.030" or even .040"--since only the end of the mill is doing the cutting.

I keep wishing that there was something in between the coarseness of a chop saw and the precision of a vertical mill--sort of a low accuracy vertical mill, that would let you run either a large diameter cutting tool across the surface in .1" chunks, or side mill several inch long slices in .05" cuts. Perhaps I just need some sort of mill vise that lets me exert a lot more force against the workpiece!