4th axis as a "poor man's lathe"

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I decided to make an upgrade (actually more than one...) of my CNA lathe.

Number one update is to change the spindle motor.



While the 180W 50V DC servo works surprisingly well, I want some more torque and higher RPM, so I bought a 600W AC servo. This motor will allow me to change the gearing from 1:3 to 1:1.5 so I will get a maximum chuck RPM of 2000 instead of 1000. I think the motor will be strong enough for me at that speed.



I made some modifications to the servo driver, added three LEDs and a small relay to the four outputs, and also a button to one input. Inside the driver there is more than enough space for the small PCB necessary for this modification. The parameters are set according to the following for this modification:

LED 1: Servo ready
LED 2: Servo motor power on
LED 3: Zero speed
Relay: Alarm detection
Button: Alarm reset

The relay NO output is connected to a 3.5mm contact, which in turn is connected to my eStop so that when everything is fine (no alarm) the relay is energized and the contact is shorted.When there is an alarm from the servo driver the relay will break the circuit and UCCNC will stop the G-code execution and all motors and halt. When the error condition is back to normal, by pushing the button the error flag is reset and the servo driver is ready again and UCCNC can start again. Of course, this condition is emergency stop, so the code can't continue from the same spot where it stopped.

This is all in theory and after bench tests. I can't run real tests yet, since I must make a new motor holder plate, and I won't have time to finish that work the coming weeks, since tonight I will be off to Hungary and Austria for two weeks.