Filament not loading on new MK3
I have a MK3 kit that shipped in late January 2018, but due to family illness I wasn't able to get it completed until today. After I finished assembly, I updated the firmware to 3.4.1. Both the Selftest and Calibrate XYZ finished OK.
To perform the First Layer Calibration, I attempted to load the gray PLA filament that came with the printer. I trimmed the end of the filament to a point and inserted it in the top of the extruder. The preheat ran normally, and I could see the extruder motor's pulley turning *very* slowly. However, no filament was being pulled into the extruder, and even after several attempts nothing was coming out the nozzle.
When I inserted the filament into the top of the extruder, I didn't want to jam it too hard but just pushed until I met resistance. During one attempt, I could see the filament through the side view-hole apparently reaching the motor pulley, but it was not drawn in as the pulley turned. During a couple of other attempts, I couldn't even see the filament through the side view-hole near the pulley, even though it seemed to hit hard resistance as I pushed it down from the top.
Can anyone suggest how to debug this at this point? Do I need to push the filament in more aggressively to get it to engage with the pulley? Or is it likely that there is an alignment problem that I need to open the extruder assembly in order to correct?
Re: Filament not loading on new MK3
i would open the idler up and see if it feeds easy by hand. possible its too tight. I put filament in. and tighten the screws so its almost flush with filament loaded. but you should be able to push it thru with the idler open. you should be able to preheat it and see it come out the nozzle too. at least to verify nothings obstructing it.
I have a Prusa,therefore I research.
Re: Filament not loading on new MK3
Thanks, I’ll check it out.
I guess at this point the main thing I was wondering is how far in should the filament go when it’s inserted by hand. Does the tip normally pass the pulley by some amount? How far?
I’m also not real clear on what the idler is supposed to do. Is its purpose to keep pressure on the filament where it enters the extruder mechanism?
Re: Filament not loading on new MK3
"keep pressure on the filament " you got it.
I think I can push mine well past it. make sure the gears that grab the filament are aligned.
I will check when I get home from work
I have a Prusa,therefore I research.
Re: Filament not loading on new MK3
So I've figured out a couple of things.
First, yes, the screws on the idler were set too tight. I loosened them up and then tightened them just until they did the job on advancing the filament.
Before I could get to that point, though, there was another issue. As mentioned in my initial post, it felt like the filament was hitting something hard before it got to the pulleys when I fed it into the extruder by hand. When I removed the filament sensor cover (the plate with two screws on the top of the extruder), everything worked fine and I could push the filament in quite a distance. However, whenever the filament sensor cover is installed, it seems to pull the PTFE tube too far toward the idler side of the extruder, and this creates a blockage for the filament.
For the time being, I'm running the printer with the filament sensor cover removed. The calibrations wrapped up nicely, and the printer is doing a good job of its first print right now (the Prusa logo). At some point I'll have to figure out what I need to do to make things work with the filament sensor cover reinstalled.