Thanks for the thoughts. All very helpful.

I'm amazed that i've not found this to be a major issue before? The machine was built for one purpose which its managed very well, running for several thousand hours quite happily. I did a basic setup when I built the machine but not much fine tuning. Its a belt drive running directly of a 15T sprocket. Still i've always wondered why it cut radius (none critical) in an odd way sometimes. looks like this combination of feed, velocity and acceleration is critical.

You suggest increase acceleration in motor tuning, as 100 is quite low. What would be your suggestion there?

Based upon your advice to lower velocity and increase acceleration whats your guess for a decent feed speed?

Thanks for all advice.