Is it harmful to run the extruded dry? I am trying to diagnose a mechanical issue and I dont want to waste filament.
Jhead at 220c
Accessible extruder
Prusa i3
Running the motor dry won’t hurt, but letting the extruder sit hot with a little bit of plastic in it that’s not moving might.
it can be harmful to heat the extruder and not put any filament through it, as this will cook the filament in the heater barrel. If the thermal barrier is not actively cooled, this can cause a jam which will require hotend cleaning. Repetier firmware allows you to do a ‘dry run’ which will execute gcodes without any extruder moves and the hotend off.
Ah, that is too bad but I expected as much. The issue at hand is a overheating issue so I was hoping to lead the nozzle at temp for extended time. Maybe I’ll reduce the extrusion instead.
Use M302 (allow cold extrudes) then you can run the extruder motor without the hotend being hot. Of course you don’t want to be slamming filament into it so be cautious.
If you clean out your nozzle with a cold pull first, it should be fine, because there will be no plastic left in there to burn. Nylon is best for that. http://bukobot.com/nozzle-cleaning
M302 if you just need to extrude with the heater off but sounds like you might need it on? What (more specifically) are you troubleshooting?
@Jarred_Baines , yea, I needed the heater on. Take a look at the problem in my last post. When I added a fan to the hotend, I started losing current. The problem was caused by overheating issues on RAMPS and resolved with an additional fan. Running a long print without filament was a simple way to test the solution but I ended up just running a long print instead. No regrets, this is the best print so far. The Prusa i3 makerfarm kit should come with fans, they don’t seem to be optional.