I am getting really frustrated with my printer.

3D Printing
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1

I am getting really frustrated with my printer. I have taken a break from printing for several months while still making designs, and now I am trying to get my printer working. I have an Einstein cold end and a J-head variant .4 mm nozzle. Last weekend, I replaced the hosing that feeds the filament from the motor into the nozzle, thinking it was damage during frequent un-clogging. The same problem occurs despite this, I may get an initial test extrude, but any time period between first test oozes and first print, and it fails to extrude anything. The motors work. I generally keep the fan on and the end hot in between.
It seems whenever I clear a clog, it will extrude once, but after testing it stops before the first print.

Any tips on where to go from here? It is annoying I have no results to show for advice. extrusion works fine the first time so I think the temperature is fine. Prontrface reads 205 for PLA, I have tried a few other temps with similar results, but don’t know if I am getting it wrong or missing some crucial variables in the settings. I am considering just rebuild the whole printhead in my frustration, but don’t know if that will solve my problem.

2

If your PLA is old it might have sucked in moisture from the air, causing frequent jams. You can try to dry it out in a dehumidifier or get some new PLA. You might also need to thoroughly clean your hotend, there might be some deberee in there that is moving around but never leaving the hotend.

3

Have a picture of the setup by chance? If you to, upload it to imgur and link it in the comments. Might help get an idea. So many possibilities.

4

You should already be able to push the filament by hand thru the heated nozzle. If it is really hard to push by hand, then it’s probably a nozzle issue. Touch the outside of the nozzle with filament. Does it melt?

5

heat is not the problem… it melts fine on the first time extruded. I don’t know if it’s a physical/design issue or a setting too hot/too cold pushing it through too fast… not sure the best trouble shooting methods to determine out of these things which it is. I replaced the tube on the thought it was either bent or with something inside causing a jam. Overall thought is heat is getting up above the pfte tube and melting the plastic, I don’t know if this is common for my setup (see above for details of print head) or if its a setting issue that could be fixed

6

@Neal_Paulus some pictures would really help.

7

I’m sorry, I don’t have the printer with me atm, what do you want pictures of (as there isn’t any failed print to show, it just does not extrude). I’m sure I can find pictures of my prusa i3 model if you need a picture of my nozzle?

8

Yeah, closeups of the nozzel and everything around it.

9

http://www.2engineers.com/shop/ceramic-hotend-chess-for-1-75mm-fillament/ is what i have

10

the problem is within this part with either too hot and getting soft before it gets far enough and jamming somehow, i just don’t know if it’s a bad design, a damaged part (either option leaning towards replace with something else, maybe solid metal like a Prusa extruder) or if a setting of temperature or for the extruder is the problem and i need to fix that or it won’t work with any extruder, i’m not sure

11

It could be that the PTFE liner in the J-head is not making a proper seal, which in turn causes the nozzle to jam after a while. If the PTFE is too short then molten plastic will build up in the gap and result in a contant increase in pressure.

12

@Aaron_Leclair Do you know if this is a common problem, or a recurring problem? I’d rather invest in a different extruder than deal with constant jamming. I have another proprietary printer, but this is the only reprap nozzle i’ve used. Does anyone have recommendations?

13

I was having similar issues with pla on mine till I ran across some forums mentioning putting a a few drops of oil on the filament. I used canola oil and it is working much better. But I’ve only printed a couple hours since. Ive got a modified Qubd MBE hot end

14

thanks! I will try this tomorrow when I get back to the printer!

15

The thing I haven’t figured out yet is how often I need to oil. I actually made a canola oil felt tip marker and will build a holder for it.

16

@Neal_Paulus it’s not uncommon for lower end hotends, is your J-head from http://hotends.com or from amother supplier/manufacturer? If it’s the second then it’s fairly likely that’s the problem. A lot of lower cost copies of popular reprap parts have a serious problem with quality assurance. You could always try and dismantle it and check the liner.

17

My bot does similar things when i use Pronterface. I switched to Repetier and it stopped.

18

Thats interesting too… Any thoughts as to why?

19

Not configured properly i spose.

20

It might be your filament. I have 2 rolls, one’s clear ABS and the other is green glow in the dark ABS and they won’t extrude reliably; Other filament works flawlessly…