Before I post a bug report, I just want to check if anyone has had this issue with the Re-Arm and I’m not sure if it’s firmware or Hardware. Both Hotend and Bed are set to PWM. It will randomly switch to Bang-Bang (full on/full off) which can be seen in the terminal. Switching off and re-seating the SD Card fixes this. It suggests hardware with having to power off and re-seat the card, but it could be something amiss in Smoothieware as well, hence the check.
@David_Sherwood - I’ve realised that reseating the card isn’t necessary, and it’s not likely the card as once booted up config is stored in memory, I discovered this by accident, but you can actually remove the card once booted.
I don’t know if Smoothieware does the same but Marlin only performs PID control within a relatively small temperature range about the setpoint. Beyond that it reverts to on-off control.
If this is the case and you are experiencing significant temperature excursions then it could explain what you see.
There is always the possibility of it being a software bug. The fact that it occurs on both PWM controlled targets and, if common code is used, might support this as another possibility.
@Neil_Darlow - Normally Smoothie will be full on until about 5c within the set point, but with this, it just gets to the set point and overshoots by about 3-4c and stays there. Where normally I’d see a PWM I just see straight on & off with no PWM at all.
Hay Ax Smith-Laffin