Once I had the Headstock Spider out of the Lewis Horizontal Mill, I needed to open up the bore to have a snug fit on the lathe’s headstock. The first step in the headstock spider boring is to setup to part in the four jar chuck for the lathe. This is a step I have performed many times, so I am very comfortable with this step.
Once the material is in the lathe’s four jaw chuck, and setup with zero run out. I needed to open the 3/8’s inch hole up to 1/2 inch. At the moment, this is the largest drill I own. It was a simple matter to open this centerline hole up to 1/2 with my drill and a Jacobs check and the lathe’s tail stock. However, it took a careful bit of feeding in order to prevent the eighty year old 1/4 HP General Electric from stalling. I really need to update the lathe motor at some point.
Fortunately, with the bore opened up to 1/2 inch I was able to find a boring bar that would fit into the hole. Once the boring bar is centered, I began the process of boring the hold out to 1.065 inches. There were not issues with this process, with the exception I was limit to 0.010 inches (radius) per pass. Any cut larger than ten thousandths would result in the motor bogging down.
All in all despite my motor issues, the boring process went without event. Once I reached my goal diameter, I double check the dimensions with the calipers. Then removed the part from the four jaw chuck. The fit up was beautiful.
Next Step, bringing the outside diameter down to size.