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.

There are known issues with Mach3 and using Feedrate Override over 100%. You're better off using a higher feedrate in your g-code and using FRO to slow it down.

Hey woodycam,

I unchecked all cv settings in general config when testing. Now i use 3.042.040 and all works smooth like butter. Using FRO often because im still experimenting with feeds so i adjust often while cutting.
If i use a newer version then the above mentioned it stutters with all feeds. Really annoying. I contacted the manufacturer of the leafboy77 and they say its not their hardware causing this.

So i just use above version now. Maybe in the future i step to EdingCnC usb.