Locating the bush hole
This is a simple and accurate way of locating the hole position when bushing a clock plate.
Machine a centre drill hole in a piece of bar, then select a steel ball bearing that will contact the outer rim of the oil dimple only.
Fix the brass into the centred hole with grease or Vaseline. With an angle plate on the cross-slide (make sure of a clear back hole), place the clock plate against the steel ball, with a push bar in the tailstock. Apply pressure with the tailstock, then clamp the clock plate to the angle plate lock cross slide.
Remove the tailstock back along the bed. Remove ball and centred bar. Now chuck a two-flute slot drill of the required size and create the hole you want.
I have used this method many times and it always creates a hole exactly in the centre of the oil sink.
William Maysey, UK
