Thread: Ball mill girth gear setup

Hi, I am seeking help with a simple formula to help me setup a spread sheet to check girth gear run outs.

I have two (2) dial indicators (A and B) setup to measure axial run out or movement. Once the readings are taken I need to calculate the run out.

When the stem of indicator A is pointing in the same direction as indicator B, subtract the values entered in B from the values in A. The different is the axial run out. For example A = 0.2mm, B=0.4mm = 0.2 - 0.4 = -0.2mm = Axial run out. Please note any the reading can be plus or minus

When the stem of indicator A is pointing in the opposite direction as indicator B, add the values in A and B. The different is the axial run out. For example A = -0.2mm, B=0.4mm = -0.2 + 0.4 = 0.2mm = Axial run out. Please note any reading can be plus or minus

I know it is fairly simple but I need a start point.

Thanks for any help. confused: