SFDeeJay wrote:Ger, I had to chuckle after reading your reply 2 or 3 times. I thought "how could UCCNC be up and running if the PC was not on". Then, of course, I realized you meant the StepCraft controller. I'm gonna stay with your suggestion and see if that makes a difference in that "ker-chunk" sound/motion at startup.
With "your machine" means Gerry the CNC. First switch on the PC then start UCCNC while the UC100 is connected and first after that should the CNC mains power switched on. Of course, this assumes that your UC100 is powered via the USB cable connected to the PC otherwise UCCNC will only start in demo mode. This is not always the case, even if for the UC100 it is the most logical. Other controllers, like the UC300 and UC400 this can be, or must be different since they can/must use external power supply. My electronics and CNC has just one mains switch, so I can't switch on the UC300 first without switching on the CNC as well. and occasionally there is a loud "clonk" sound when the steppers get energized. The main reason is that when the UC300 is powered up it does not initialize the outputs, or the outputs are set to the wrong level and not before UCCNC is started that the UC300 gets correctly initialized. So, when UCCNC (or Mach3) is not started but the UC300 is powered up the motors get enabled and energized and this causes a large bang and a slight turn to the nearest full step position. This should be pretty easy to fix in the firmware since after the first configured start of UCCNC the software knows which state the outputs should have in a reset condition, and the UC300 firmware should start in that condition, regardless if UCCNC is running or not. Not a big deal, but annoying and not logical. Perhaps there is another explanation to the clonk also, but in firmware I am familiar with, this would be a non-issue and solved with very little effort. Perhaps the firmware memory is full and it is not possible to add more instructions to it, but I don't think this has been addressed at all.
In short: Do as Gerry means, follow the power-up/start sequence checklist:
PC: ON and Windows is running
UC100: connected to PC, LED indicates OK
UCCNC: started and ready
CNC: powered up
You should not get the clonk but in my experience this may still happen and most of all, even the spindle motor can take a few turns (unless you use Modbus) until UCCNC is up and everything is powered up and ready, so be careful during start-up, regard that as an uncertain condition until everything is up and ready.