Just to describe myself, as requested:
I’m a retired design engineer, but over the years have done a fair amount of hobbyist metal working – starting with a six month workshop training course over 50 years ago now. Got a very old small 8″ swing Myford lathe, arc welder, pedestal drill, small CNC router, 3D printer etc.
Introductory question: need to machine circlip grooves in some 1.5mm silver steel bar. The grooves need to be 0.5mm wide, and 1.2mm bottom diameter. First attempt, despite feeding very slowly, with an HSS tool (which from what I read should be OK) bent the bar and snapped the (very fragile) tool. Think I ground too much top rake on to the tool and it dug in. What should the top rake be for something like that?