I have been using magnetic test indicator holders with the quick release magnetic bases for setup work on the lathes. However, I thought it might be easier to use a flexible arm held in the quick change tool post for most of this work. Shown is an easy to make aluminum bracket designed to fit in the same space as a 3/8” square cutting tool holder. The bracket part was made from 0.625"x1.25” 6061 aluminum bar stock, milled and fly cut to size, drilled and reamed with 5/16” diameter holes to hold the adjustable arm base in either horizontal or vertical positions, and locked in place with an 8-32 SS cap screw. I purchased Shars Tool online the adjustable test indicator holder arm that fits any test indicators with either 3/8” diameter shafts and/or side dovetails.