I am looking at the feedrate issue. This needs to be addressed before the clunking in any event.
There was a rather glaring error in the feed-rate calculation that overlooked arcs. Here is a hex that corrects that. I’m positing it now so you can give it a try. I will be testing this over the weekend before pushing to edge if it’s OK.
Chris – I have been testing the arc changes on a Shapeoko and on a Probotix and am getting correct arc movement and no clunks. Can you try on your machine? What kind of machine are you running and can you post your settings? This will help work though exactly what you are seeing and help to develop a better strategy for short, isolated lines.
Chris – If you are adventurous you could try this build out as well. It addresses the issue of short moves and works down to about 0.02 mm on my shapeoko setup.
There is still a lot of testing to do – I will probably be running files through it most of the rest of the weekend, but I would be very interested in your feedback if you get the chance.