So big news everyone..... and a big problem for some...I spoke to the real factory and more specifically the lead engineer who developed the DDCSV1.1( i lived in China for 5 years so still have sourcing contacts) turns out my problem is because my X and Y step rates are not equal.... this is why the arcs are off. So even tho you can set different steps per mm for X and Y it will not work out. so X and Y pulses per step must be equal... my machine uses a ball screw on X and a rack and pinion on Y and has different steps per mm... wish I knew this before...

So basically if your machine has the same steps per mm for X and Y your gold ( this is also why you can't do arcs in Z or helix moves all axis must match in steps per mm) if your machine does not have equal X/Y steps this control will not work for you.

On the positive side, the DDCSV replacement ver 2 is 40 days out and will have this option and a whole new software (no the new software will not work on the 1.1). Luckily I have a smaller router that has the same ball screws for x/y I can use this on and the factory is sending me a V2 to beta test.

chriscnc,

I had the same problem where I installed the DDCSV on a small Emco lathe, the one axis was 2mm per rotation and the other axis was 5mm per rotation, and I also picked up that the G2 and G3 commands would track the wrong arc. I however could reproduced the arc error mathematically using the ratio between the two axis and thus realised that they have screwed up the arc math constants in the algorithms when the axis were not the same. To solve for this error I changed my Microstepping resolution on my motor drivers to reflect the inverse of the mm/rotation ratio between the two axis. My lathe now runs perfect arcs.

Just another point, I see many reviewers of this product make the statement that this controller cannot be used on a lathe, and while this holds true for threading and tapping, which is simillar for a milling machine scenario (there is no inputs available for spindle orientation), it is running perfectly on my small lathe install. I am using Autodesk Inventer with the Cam module and I have written a DDCSV Turning Post for Autodesk.

Marius