Print stops extruding mid-job
Bonjour friends,
My printer started having an issue for the last 2 prints where it stopped extruding mid-print (the infill of the part is clearly visible). However, the interface says the job is 100% "done" and the extruder is in its home position. I initially saw this issue (never encountered it before) on my first time trying a transitional multi-color PLA filament from a lesser-known brand, so I figured the filament might just be cheap and have clogged the extruder. I removed the multi-color filament and loaded some tried-and-true black Hatchbox PLA, but then THAT had the same issue, and the print after that as well. I made sure that the filament was clearly extruding when loading it and that the first layer for each print was laid down correctly. I'm guessing some of that multi-color stuff might still be clogged in my extruder. Another idea I have is that the Bondtech gears seem to have a bit of plastic accumulated in them and I'm thinking they might be slipping on the filament at this point. When I pulled the multi-color filament out of the extruder to unload it, I noticed a narrow portion of the filament feed where the gears were probably grinding on it like a smooth car tire in the snow. I'm going to try to clean the Bondtech gears and check the extruder for clogs. Until I get to that, anyone else have ideas? Seen this kind of problem before?
Re: Print stops extruding mid-job
Matt, how long have you had your printer? I had some of the same issues. I printed for about two months with no issues then one morning I checked on an all night print and there was only about 19mm or 3/4 of an inch of product. The printer said it was 100% successful.
Have you used cleaning filament? Try that after you clear your clog. I tried several methods and one I did use was to preheat the nozzle to about 20 degrees Celsius above the highest temperature filament that you had in your printer.
Initially I couldn't get the cleaning filament to feed so I opened the Extruder-idler door and hand fed the filament.
When you remove the filament from the extruder do you have any issues removing it? I started to have bulbs form on the end and had to lightly pull on it during removal or it would jam.
Re: Print stops extruding mid-job
Thanks for the suggestion, David. I received my printer kit in late June and had it assembled and printing by mid July, so it's been printing away for about a full month now. I've been printing an average of about 2 hours a day up to this point.
I haven't thought of (or heard of) cleaning filament until you mentioned it - I might give that a try. I'd rather do that than the atomic pull method if I can help it.
Similar to what you mentioned, I did have a little bit of trouble removing the filament after each suspected "clog". The extruder would be heated and everything normal for removing filament, but the filament just wouldn't come out very easily. I had to tug on it a bit (one hand on the filament and one of the extruder). Once it would come out, I noticed in each instance that the filament had a slight bulb shape at the bottom and a slight narrow portion a little farther up the string.
Re: Print stops extruding mid-job
I had the same problem. My MK3 printer worked beautifully for the first 200 hours or so of operation. Then extrusion and unloading problems became increasingly frequent until finally the printer couldn't even complete a first layer.
Thinking the problem was somewhere in the hot end, I pulled it apart and could find no obvious issues. Reassembled the hot end using a new PTFE tube, nozzle and an upgraded Micro Swiss heatbreak (highly recommended, BTW), but the problems continued.
Upon closer inspection of the Bondtech pulleys, I noticed that the idler pulley shaft had slipped out of one side of the extruder-idler door, resulting in the filament not getting gripped firmly during feeding. This is difficult to see but quite apparent if you are able to wiggle the idler pulley by hand. I removed the door and re-centered the shaft but I think the problem will eventually return.
Myself and some other users who assembled the MK3 kit noticed that the 18 mm shaft included with our kits seemed too short. I think the printed part is actually designed to use a 22 mm shaft and incorrect parts ended up in some kits.
I reported the problem to Prusa support but haven't heard back yet. The 22 mm shaft is available from Amazon, albeit at an absurdly inflated price: https://amzn.to/2vSY0jY
Re: Print stops extruding mid-job
The 22 mm shaft is available from Amazon, albeit at an absurdly inflated price: https://amzn.to/2vSY0jY
Sorry all, but I posted a link to an incorrect part. 3mm x 22mm is the required size.