JV has become increasingly interesting in machining. His godmother’s neighbor is a retired machinist and JV visited with him yesterday. He was lent a high school shop manual. He has begun reading it.
- put the work rod in the vise
- lay the center square against the side of the rod near the end
- put a ruler under the center square across the top of the rod
- scribe lines along the ruler
- move the ruler to the other side of the square and scribe lines
- rotate the rod 90* in the center square
- repeat steps two and three
The second way to locate the center of the rod is the hermaphrodite caliper.
- put work in vice
- adjust the caliper to half of the diameter of the work.
- place the curved “leg” of the caliper on the side of the end of the rod and rotate.
- scribe a quarter of a turn creating a semi-circle.
- do this three more times rotating the piece 90* each time this creates a concave square.
I did not understand the third way.