This has been a problem for a few weeks now so I thought I would share it...
When unloading filament from the M200, the hotend heats up, then the gear backdrives the filament out of it where the user can easily pull the filament out of the inlet hole on the top of the extruder stepper motor mounting plate.
Recently, the filament has been getting stuck in the printer head once the gear backdrives the filament out of the hotend (every time with glass and abs as those are the only filaments we have). My best guess is that when the solid filament pulls apart from the heated and more semi-solid filament in the hotend, the gear mashes it up into a more oblong-elliptical cross section, which in turn has a larger diameter that is greater than the circular cross section inlet hole in the plate that the extruder stepper motor is secured to. This causes the filament to be stuck between the top of the gear and that first inlet hole in the stepper motor mounting plate leading to the gear and bearing section.
To fix this, I have been taking off the screws on that plate and cutting the mashed up end off so I can pull the filament out...every. time. The next step is that I am going to have the machine shop here at my company just bore out the hole a little more so that it can accommodate the mashed up end of the filament.
Anyone else having this problem? Has this topic existed in a previous thread before? I only have about 150-175 printing hours on this printer and I am having more than just this one simple problem. I am going to try and run a loading/unloading trial and measure the largest diameter that I see in 5 trials and bore out the hole to a little larger than the average diameter that I observe.
Just for me, there is not any trouble with unloading filament, except the gear is 'dirty'.
If it does not work on the first try (not all coming out of the extruder), I just select the unload option a second time and probably assist with pulling the filament.
No need for any further action here.
But I don't print Z-Glass. It's not a good filament (my opinion), I use a transparent ABS instead.
It still doesn't come out even when you pull hard and unload it a second time, third, fourth...even n number of times. The reason for this is that the filament clears the gear; the gear did it's job. It is the filament not fitting in the hole as a result of the end of the filament being mashed up by the gear. I also clean the gear every time I take apart the printer head.
I really have to pull hard to get the filament out. I feel it is really bad for the rails to do it continuously though. This is why I have been taking apart the printer head every time I need to switch a filament and even hotend maintenance.
It still doesn't come out even when you pull hard and unload it a second time, third, fourth...even n number of times. The reason for this is that the filament clears the gear; the gear did it's job. It is the filament not fitting in the hole as a result of the end of the filament being mashed up by the gear. I also clean the gear every time I take apart the printer head.
I really have to pull hard to get the filament out. I feel it is really bad for the rails to do it continuously though. This is why I have been taking apart the printer head every time I need to switch a filament and even hotend maintenance.
Too much maintenance - just kidding.
Strange, though: in the first (a lot of) hours of printing I didn't even know where any of the screws were - no need, it just worked.
Maybe try once more a serious cleaning, new nozzle and use a wire to check the alignment of all the parts involved, top to bottom.
I've seen here somewhere (and used) an alternative way (by Andre, if memory serves): skip unloading entirely, just cut the filament above the plate, press load and after the 'old' one is gone from view start inserting the 'new' one.
I occasionally have "the blob" from the hot end get stuck in the passage below the gear (pulling gently during withdrawal while everything is warm usually prevents this) but have never had any blockage above the gear. Yeah, just drill it out.
Me too. I made the suggestion that if Zortrax extruded briefly before unloading that would wipe off the small blob that is sometimes present at the end of the filament.
To test if this works you can wait until the nozzle is fully heated, then turn off the printer and push the filament down quickly before pulling out. Comes out smooth for me. I do a similar thing with the Flashforge printer.
Me too. I made the suggestion that if Zortrax extruded briefly before unloading that would wipe off the small blob that is sometimes present at the end of the filament.
To test if this works you can wait until the nozzle is fully heated, then turn off the printer and push the filament down quickly before pulling out. Comes out smooth for me. I do a similar thing with the Flashforge printer.
Amazing, I recently had to change filament on my Flashforge and didn't think about this method.
Needless to say, the extruder is opened and I had no time to put it back. All because of a big blob inside it.
It's so logical and simple, I'm mad at myself for not thinking it...
I'm also having this problem, a blob that can't pass through the exit when unloading filament. What I'm doing as workaround is (annoying...) first load filament then immediately unload and push it out, don't let it cool.
I have this problem with every change, is there any other solution, it feels like [as you say] the opening immediately below the cog is to narrow. Won't even go through after a good clean out...
Well I guess that I'm not the only person who has had this problem. I did work out a technique that has solved it, at least for me.
Here it is:
1) Watch the readout for the extruder heat-up.
2) At 99%, grasp the filament and exert continuous gentle upward pressure.
3) At 100% and when the feed gear begins to back the filament out of the extruder, help it along with upward pressure in one continuous smooth pull until the filament has exited the printer.
4) Solved my problem and I get a clean pull-out every time now.
Before, what was happening to me was I wasn't fast enough with my pull-out and the small amount of cool-down time after the gear stopped backing the filament out and before I pulled on the filament was allowing the filament to form a small ball on the end. This made pull-out very difficult.