I have an intermittent problem with my printer which I can't figure out. I don't know if it is hardware or software related.
Just as the nozzle lowers to the bed and the print should start, the extruder sometimes suddenly goes into high speed retraction. I have to press emergency stop to stop it. I really mean high speed. I have to catch it quick to stop the filament from flying back out of the bowden tube.
I restart again without changing anything and it may do it again or it may print normally. Seems to be random. Once it starts printing it is fine all the way through. The problem is only at the very start. It is the same whether printing from a pc or an sd card.
I am using an Arduino mega 2560, Ramps, Repetier firmware, Repetier Host and Slic3R. Wade extruder with bowden setup.
