Hi Tony,
I'm a big fan of your work and I love your well-described projects on the home made tools site but this one caught my eye:
https://www.homemadetools.net/homemade-dial-indicator-mount-4I used to use a similar method for centring stuff horizontally until I took a machine rebuilding course. On the course we were warned never to use this method of rotating a gauge - especially a heavy dial gauge - about a horizontal axis for dialling in a part or tailstock ram etc because the weight of the gauge will tend to bend the supporting bars almost regardless of how sturdy they are, causing the reading to change as the gauge swings full circle.
We were sceptical until he did a demonstration where he put a mag mount on a small surface plate, zeroed the DTI to the plate. He flipped the whole assembly over and the DTI moved nearly 10 thou. If you used that example setup to centre a part it would be 5 thou low but read zero all around.
It was plainly obvious once demonstrated but up until that point I was blissfully unaware of the issue.
