What are your strategies for fixing jams in the hot end?
(Printer I refer to is a PowerSpec Ultra)
I also ran into an issue when I went to reassemble one of the extruders and found out the spring had been thrown out (curse those ignorant people that don’t understand things have a purpose). What do you recommend I get to replace this? I bought some off amazon marketed as extruder springs but they put way too much tension on the filament, to the point it grinds off filament without any extra agitation.
First off when it is working correctly. Please the printhead into a feed in mode as if your loading filament and allow a bit of filament to come out. Leave it feeding and squeeze the trigger on the appropriate side and pull out the filament as quick as you can. This insures the majority of the filament has not had a chance to soften and always a clean extraction. (This is good technique for most printers.) Also do not let PLA sit loaded in an unused print head as it does get brittle and can brake off while moving back and forth with the print head.
If you have a situation now where the printhead is jammed, pull the stepper motor off, heat the head and work another piece either into the extruder tube or use needle nose pliers to extract the piece that is stuck in the extruder tube (after everything heats up. It most likely has a blob on the end; especially if you used the slow unloading method. (Squeeze the trigger and pull when hot is the only way to go to insure no clogs.)
I agree with dmyers about the filament going brittle. It is a real pain when it snaps off. As far as unloading the filament is concerned: what he is referring to is called a ‘Cold Pull’. The best way to do a Cold Pull is to let the head cool down, then start it heating back up again and start to pull on the filament once it gets to around 160 - 170 degrees. The colder you can pull the filament out the more filament and dust / contaminants will come out with it. The end of the filament can be snapped / cut off and discarded leaving a nice pure filament end.
Another thing you can do is: cut a piece of cheep washing up sponge and inch or so square, make a small hole or cut a slit in it then make the filament go through it before it goes into the extruder. This will wipe any dust off of the filament and minimise contaminants getting into you hot end.
Another thing I have had in the past is that: the starting gap between the hot end and the bed was too small making the filament build back pressure and overheat in the hot end which can carbonise, thus causing a jam!!!
Spring
I don’t know if the spring on your printer is pushing or pulling so I hope this helps. Simple thing to do here is to cut the spring down with plyers and stretch it a little. This will lesson it’s strength / tension.
You spend all day printing successfully, You go to bed and wake up the next day (filament still loaded and no settings changed). You start another print run and (it works the same flawlessly or, it fails big style). Your heating was off for the night the room cooled and moisture/condensation dampened the filament loaded on your printer (nearly every one leaves the filament loaded). The filament is brittle and snaps off at the extruder or gathers hot end clogging dust. The first layer is too squished or too loose. Hey!!! Every thing is changing and is always in flux!!! (ambient temperature, expansion of the bed, hot end, filament or planet MARS! just aligned with VENUS!!!). Sometimes (sorry for casual swearing) SHIT happens.
3d printing is not a science it is an ART. I spent 8 hours trying to do a really simple print with failure. Went away had a couple of glasses of wine, chilled out and gave it another go (relaxed). Worked great with another fantastic print (relax don’t try too hard) remember, we do this cos it’s fun!!!
Because of thermal dynamics everything is always changing so go with the flow and keep trying. When ever you need to figure something out or learn do a youtube search including the word tutorial and you will find a video that will help you.
If you need more direct help I am very willing to help: just email me at dave_jolliff@hotmail.com and I will lend my 3 intensive years of knowledge to help you solve your problem.