Mastercam will cut electrodes as well as cores and cavities. You might have to do some prep work on your geometry to get what you want. It does not have the trim that WorkNC has. It's a nice feature to get rid of unnecessary cutting but it's not a must. I recommend that you find a local mold shop that uses MC and ask them if you can have a looky loo.

Thanks for reminding me why I hardly ever bother posting anything here anymore.

That just seems to be the nature of Mastercam. I run into this sort of thing all the time cutting mold detail. There is no fix that takes care of everything. I found that changing boundary to center and reset my upper and lower limits sometimes gets rid of some of the crazy jumping around. Sometimes I need to add another in between tool (in your case maybe a 3/8 dia. before the 1/4). Unfortunately this legacy toolpath still works way better that some of the newer rest toolpaths. Another beef I have with leftover is the fact that MC does not seem to be aware of exactly how much stock is leftover and when a small tool goes into the leftover area, it gets buried in the stock and sometimes break. (Can you say how much we need to drop parting line to fix that?) You have to experiment a lot and hopefully find a work around. WorkNC did a fantastic job with left over stock 20 years ago. It's sad that Mastercam is still so far behind with this technique.

I've had this problem on a persistent basis since using 2017. Exit MC and restart is the only solution I've found. Maybe MC is expecting us to use some mental powers?

Weird. Didn't have this problem with X9. I'll try it. Thanks.

Seems that every so often 2017 no longer wants to chain. Yes, I checked level, planes, duplicate entities and so forth. If I exit MC and restart, voila, achaining I go. Graphics issues, perhaps? Thanks in advance