I have a strange problem with my Printrbot Simple Metal.
When I start printing it's suddenly trying to go off axis before starting to print. All is fine once it actually starts to print, but it's very annoying to hear the sound on the start and end of each print.
That can't be good on the motors and chains either, something is going to give out at some point.
Here's what that sounds like: YouTube - IMG 5600.
My OctoPi settings are:
It is very common that FDM 3D printers "home" their position at the start of each print (as defined by the slicers preprint g-code). This is done by deliberately running the end effector towards its expected X=0, Y=0 position until it hits the endstop switches for each axis. Could it be this behaviour you are seeing? If so, I would suggest checking that your endstops are functioning correctly.
You can manually activate this homing action using the G-code G28 in (for instance) Pronterface. Alternatively, you can verify that your endstops are actually working using the M119-command while pressing each switch manually.