question when using chinese servo drives with original motors

Hi everyone

I haven't updated this thread much as I have been getting help mainly through the mailing list and from linuxcnc guys I have met you all know who you are!

anyway just wanted to update this thread as I know have something to offer others going down the linuxcnc path I think

I have just tonight got my cnc mill working for the first time with a spindle running and working


For those who don't know I am running step and direction using mesa 5i25 and 7i76 cards. and I am using chinese matched servo motors and drives. they are 4 kw motors, I think direct driving 16 mm pitch ball screws so this machine is pretty fast. I have it toned down or otherwise its acceleration can almost shake the whole 5 ton machine around at high rapid and I will blow the ballscrews up.

I still need to get the toolchanger working and the auto oiler and a decent E stop, but that is in the works over the next few weeks hopefully. And I would also like to connect the simulated encoder output from the drives into linuxcnc as soon as possible so I can home to index and also actually check how accurate the servo Pid loop is. I think I will need a 7i84 encoder card for that but would appreciate any help from those that have gone down this path before me. I think it might be a bit harder then just using +-10 volts and a 7i77.

the other benefit I have seen from closing the loop in the controller is that when I push the E stop in and disable the drives the I lose position and wouldn't know if the drives moved while turned off. while if the drives are disabled the encoder counting still works which means I can still know where I am without homing again.

Other than that I am pretty happy.

Next project is get Probe basic aka Qtpyvcpt working on this mill so I have a nice looking controller and awesome probing cycles.