I think that’s where I’ve landed on this – I’ll just fiddle with the diameter I tell the CAM program to make this test block come out right. For a given endmill, DOC, feed rate and finishing pass depth, I would expect that adjustment to be pretty constant, as it’s the value that compensates for flex in the machine for that particular configuration.
Fortunately, there are very few times when I need this level of accuracy – it just happened that the first “big” project I wanted to do was one that did. I think there were plenty of lessons learned in this process and I appreciate everyone who contributed.
Though I’d still like to see someone with a well-tuned LR4 produce an accurate cut of my test block without adjusting the endmill diameter in CAM!