The South Bend needs a taper pin to hold the handle onto the tailstock. When purchased the handle was held on with a roll pin, that was not very effective. The hole was "measured" with transfer punches. The large diameter was a good fit for the 5/32" punch. The small hole was somewhere between 1/8" and 9/64". The size of the collar on the handle is 0.840".
Taper pins were looked up on "Machinery's Handbook". Using the information in the Handbook a calculator was made to determine the small end diameter for any length of a given size taper pin. (Taper pins are sized by the diameter of the large end.) The calculator indicates the small end diameter should be 0.1385". I do not plan to harden the pin. I also did not plan on putting an accurate radius on the ends of the pin, only filing or sanding a chamfer.
The plan for making the taper was to turn the stock down to the large diameter, 0.156", and rotating the headstock approximately 1.2°. The angle of the headstock will be adjusted to 0.25"/foot or 0.021"/inch with a dial indicator.
A 0.25" steel round bar was placed in the chuck with about 1" exposed. This was reduced to 0.156" for 1". The headstock was rotated about 1° and the angle was checked with the dial indicator. The headstock was rotated in small increments and the angle was rechecked until the displacement over 0.75" was between 0.015" and 0.016". A 1" length was reduced about 0.021" to produce the taper. The free end was rounded with a file. The stock was parted off at 0.84" from the non-rounded line on the stock. The final overall dimensions are 0.837" long, large diameter is 0.154" and the small diameter is 0.123".
The small end was significantly smaller than expected. The pin fit well in the hole and was gently tapped in with a ball peen hammer. Now I can get the drill chuck out of the tailstock!!
