Quick update. I've solved my issue after further forum hunting and found two significant sensitivities. All with version x.66 I've found that with mm units, Stop CV on angle >90 deg, no backlash and CV Dist Tollerance set to 0.02mm I could achieve smooth motion if I set the feedrate override to 50%. The little jerk on every line went away. When I increased the tollerance to 0.05mm I could set to 150% feedrate before it came back. The feedrate in the code is quite varied (90 to 300), and well below the motor max speed. So, as is noted in other posts, feedrate overide does have an influence on behaviour. Also, its obvious small CV tollerances would be difficult to achieve as speedrates increase, but this is a small part and fairly slow feed and this issue was with no change in path (a split straight line). Anyway, the tollerance is a much more sensitive parameter than I expected and very small changes make quite a big difference to smoothness.
Anyway, very happy my new machine is able to be smooth.
Does anyone know if it is normal to adjust this for different GCodes each time? What is the best way to do this?
Gobbya, I'd be really interested to know what CV Dist Tollerance you used when you tested with 66?
Woody.