It's not _totally_ straightforward but I think I am getting close to nailing the settings. It seems that the cheap 0.1mm cutters I am using are hugely inconsistent. I get massive differences in trace widths with the same settings from cut to cut... Grrr. Might have to look for some that cost more than 25c each!
1st - MDF to see if I had the size right
2nd - No autolevelling. With a 0.1mm depth of cut, this is a critical feature to use
3rd - Perfect quality of cut, but traces a bit thin and design not yet reversed (as it's a bottom layer)
4th - Reversed ok, traces still too thin
5th - Nice thick traces but several areas where they ran together! shorts all over the place
6th - Traces still too thin and on doublesided board so not usabe
7th - Traces too thin... Grrr, I thought I was learning
8th - with some soldered headers. Traces ok but spacing between traces and ground plane far too narrow - impossible to solder
9th - over-rode width of cutter and added a few extra passes to dramatically increase isolation of traces. Nice clean and sized traces. Good amount of room to ground plane so should work. Is doublesided so have to sand of the copper on the other side. Might try again with even more passes on a single sided board.
Working on the 10th now but I think the traces are going to be way too thin... Just about run out of single sided blanks too!
Cheers - N