Yes Jonathan there is several line on each part.
so if I slow the feed rate down and plunge rate down even farther it may give me a better finish.

how low should I go, can you give me a starting point please

I did once run it so slow that my y-axis stalled and the cutter started cutting at the wrong depth and direction (a big cut line running through my work)
I will upload a image of this later if you wish

my step over is set at 5%to 8%


James