When I’m porting cylinder heads or otherwise using the dividers, once the size is set, I put a couple witness dabs with a high visibility pen, so I can see if I’ve inadvertently bumped it and changed the setting. It’s a time saver over checking it occasionally against the calipers and you won’t accidentally “go too far” if you miss that it has moved. I’ll also do this on the boring bar mic with a sharpie. You can see at a glance that it hasn’t moved. Simply wipe them off with solvent when done.
Ron Flood
Cedar Machine
North Branch, MN