Hello
If you notice the programming the radius information is given by Z axis position. There seems to be two schools of thought: 1 is put the radius information in the Mach 3 screen as you and ger21 suggest and the other, which seems to me Hoss has said is raise the feed rate to 200-300 or more and suddenly you get much better feed rates. I tried the latter and crashed my controller. I don't whether the BOB which was probably suspect, I felt that for some time a C-10, or it was too much for the system. I have a new C-11 board and gecko drivers and testing runs fine. Will be finishing the new controller box today and should be up and running. I can try both methods. Next step is to buy a power cleaner of sufficient size, I believe the power sine wave has a lot of garbage in the sine wave, already use one a gem scale which eliminated the voltage fluctuations which played havoc on its accuracy.
I built a new controller box out of a tower so there is room for expansion and reduction of heat through 3 fans. I have heat-sinked the Gecko Drives and now every component is opti-isolated. Separated the power supplies from the rest of the equipment and added a power switch for the 4th axis so the driver will not be powered unless it is in use. I have isolated the ESS smooth stepper power with an external charger.
Still don't know if the KL-5056 and 8070 D steppers are harmed or not, if I can determine how to test them I may use on another project either running an old craftsman lathe 6 x 18 or a 4 axis router with much smaller stepper motors. I am very sure that the cheap C-10 board is not functioning. I have one rough running 570 oz NEMA 23 motor, which I replaced always keep a spare,, the cheap Chinese stepper motors do not seem to have great life spans. I will buy better stepper motors in the future. I have lost two of them in 8 months. It may be either the stepper drivers or that C-10 as well. I have kept the drivers just under 5 amps for the 570 oz motors.
I have pretty heavy usage for a hobby machine, already wish I had a bigger mill (Taiwanese built) than the G-0704. I have a lathe which has tremendous tolerances, which will never be a CNC.