I am looking at rebuilding my robot for CNC tending but was wondering if there is a way to stop the robot from going floppy when the Emergency stop is hit as this can cause problems. Most industrial robots have electro mechanical breaks and absolute position encoders is there a reason not to use motors with brakes on them.
i guess it is the price tag of using motors with brakes and also absolute position encoders on robots in this price segment 😀. Another idea could be that you connect the emergency stop (on AR4 with the separate box for the electronics it was connected to the ENA(-) Pin of the stepper motor drivers which causes a stop category 0) on pin39 on the teensy board. This pin is used as EstopPin with INPUT_PULLUP mode and if set to ground, the stepper signal generation is "paused" (i would say similiar to a stop category 2).
Implementing relays to close or short the stepper motor circuits/coils when power is lost is a practical solution to control the motion of a vertical slider, preventing it from free-falling and ensuring it glides down slowly instead. You can try the same method with the ar4...
