I have had my growth series for a few years now. Its a love hate relationship for sure. When I first set the machine up it made pretty descent bolt holes but since changing to Acumove 2 the quality of my bolt holes well they suck. I did do some adjustments to my lead screw y axes end play which made a huge difference on larger holes but I still can not get a descent bolt hole. see pics. This stainless first time cutting stainless. both sides I also got a lot of curf. second photo is back side.
Those hole look a little small. With "conventional" air plasma you should be getting 2:1 ration on bolt hole size: material thickness. Also changing things like LEADIN radius and those things will also improve your hole quality.
The holes are 3/8th in .25 thick stainless. I did notice my machine making terrible circles. So I started looking at the leed screws and they were tolerably out of wack. Tightened all that up and shes running good. But when I do bolt holes no good. I guise I'm better off doing a pierce only But I'm not sure how to go about that. I usually use a good grade reamer on my bolt holes. How do I do just pierce so it ends up in the center of were the hole needs to be. I feel bad for Ziggy when he gets me in class in June.
Pierce only is generating a 1/8" circle and when you generate the tool path you will get a pierce hole. Drill from the backside then you wont be killing bits.