Hi Boyan,

My name is Dimitris and i am writing you because i did the same mistake... I used 8 pokeys57cnc cards to construct 8 similar 3-axis cnc machines for a customer. I trust these new for me cards because in the past i have successfully constructed a lot of cnc machines, using a tiny mach3 parallel communication board and mach3 software. And i can sure you that these machines are still working perfectly aftes 10 years of working without any kind of problem.
Now i am really sitting on fire because i have the same problems as you. The axis not always stops in the given position. Sometimes stops correctly and other times (randomly) stops between -1 - +1 mm. My mind its gonna blow.
Fisrt i had the same problems as you, as i using the extPokeysRelay boards. Finally the problem was the noise. I solve it as i "dress" the wires with a grounded metallic fence (for EMI protection).
Now i am trying to solve this f*** positioning issue. I am using the Leadshine DS1008 servo drives and as you, i tried to change the PID parameters. The movement of the axis now it seems better but still i have the same positioning problem.
Could you please advise me how the f*** can i solve this problem? Is something wrong in the mach3 parameters? Is the noise? Must i EMI protect the axis driving wires too?
Any ideas will be veeeery welcome!!!!!

Thank you in advance