As the title says, I have my BF20 spindle running off mach. My motor RPM is not linear. When I run the spindle at max speed in Mach, I setup my max speed (actual) with what mach is commanding by adjusting my C6 board Pot. Problem is if I try to set Mach spindle speed at half, my actual rpm ends up 200-500rpm lower. If needed I will put a Tach sensor on the spindle but it will require another BOB as my C35 is full.

Can I manually adjust the output curve for different speeds?
Thanks,