The lines on the side of the plate have to be in ink so your Dial indicator will move over them without falling into a scribed line and cause and error in the readings ......
Later we added a 1/2" mark above the 2" mark on both Bump and Droop.....
Now if we are going to use Dial indicators to measure how much the hub or spindle moves we need a good strong and heavy base to attach the dial indicators to....
This one we made out of some 2"X 2" .120 wall tube we had laying around..... cost $12.00
