Every day frustrating startover

Hi there everyone!

I`m new here and new to 3d print as well. I bought a prusa i3 kit, 3 months ago, I assembled it and started to "print". I had some good and bad days, motsly bad I´m sure.

No matter what I try, and I´m trying everything I read here, I can´t make this thing to work consistently. Today I calibrated it all day long following Hunter´s guide, in the end, I tested with my test model, everything was fine. Some hours later when I decided to try another print, same old story filament didn´t came out of the nozzle. It seems that every first print after the hotend is cold will not work.

Please help me find whats wrong...I may sound a bit dramatic, but ... in 3 months i can´t not count one time that i´ve printed one day after the other without having to unasseble parts and check everthing again, and again...

Its a Prusa i3 with

Ramps 1.4
Wade´s extruder
1.75 mm E3d hotend
Printing throug Cura
Marlin as firmware

Thaks a lot.

After you heat up the hot-end, have you tried priming the extruder?

Something like this:

G1 X0 Y0 Z40 F1500 ; Move the print head 4 cm off the build plate, and to the far corner
G92 E0 ; Reset position of E to 0 -- then, for the next single command we can ignore absolute/relate mode, etc.
G1 E50 ; Extrude 5 CM of filament

Then take some pliers or scissors and remove the filament coming out (careful it's hot).

Now try to print.

First question: do you retract the filament or you leave it in the hotend?

Second question: do you have a fan runing constantly on the hotend cooling the aluminum fins?

Third question: do you turn off immediately your printer or you leave it on for a while?

Fourth question: it's a Chinese e3d or a real e3d? Does the barrel have a PTFE liner or it's only metal, can you measure inner diameter?

And final question: what temperature are you using and what material are you using? It's this happening with PLA?

Guys, sorry about the delay on getting back here.

and, of course, thanks for the answers.

I tryied to extrude some filament before every print, and it got better. But I have some other issues.

First let me answer ggherbaz.

1 - I do not retract the filament

2 - Yes

3 - I dont have a rule for that, but, I prety much wait for some time

4 - China and it didn't have the PTFE, but I noticed that and bought one. 4mm external with 2mm internal, it fits perfectly.

5 - opaque PLA at 175

The other issues:

I was having some curling of the filament from times to times inside the barrel, thats how I findout it had no PTFE tube inside. Now the PTFE goes up from the barrel until it almost touch the hobbed screw. It got better this way, but sometimes , for some reason, the extrusion doesn´t occur and the motor , obviously, continues to push the filament, so, it curls near the hobbed now, since it doesn´t have space anumore to do it inside the barrel. I tryed to low down the flow, it got better too, but my pieces are starting to come out weak.

I really don´t know what to doo anymore to stop this curling of the filament. I mean, i did one last thing and I´m testing right now: I bought one inductive sensor and I´m trying to get rid off any problem with bed leveling, because I noticed that the extruder was not extruding at some points of the bed, just scratching the hairspray, while perfectly printing on other poits.

thanks,

Hmm, this sounds kind of similar to the troubles I had when I first set my machine up. The filament would randomly jam and I got to the point where it simply wouldn't extrude at all. What I found was that each time it jammed the hobbed bolt mashed the filament and distorted it, once that distorted part got to the extruder it jammed and the hobbed bolt mashed a bit further up the filament. Rinse and repeat.
The fix was to slacken off the hobbed bolt idler pressure so that it wasn't squashing the filament and to cut off and throw away a section of filament and start again. I learned a lot about how extruders work that day.

csambrook is right about the idler, you need to play with its tension. Your main problem is with temperature though, you are extruding at too low temperatures and that it's a jamming on the way. At those low temperatures it only takes a long extrusion for the nozzle to cool down to the point where can't extrude no more and your hobbed bolt will jam or eat up the filament, raise temperature to at least 195 or higher since it is an all metal hotend, with my Hexagon hotend I extrude PLA between 200 and 220.

I always retract my filament at the end of every print with a G1 E-12 F1200 in the end G code, and the reason is simple: it clears the nozzle, protect the PTFE liner (on my J head and Chinese V5) and prevent plug formation.

You mean retract it all? Nonthing left inside the barrel, or just retract from the nozzle itself?

12mm clears the nozzle and heater block and leave the filament in the cold zone of the hotend. You don't need to retract it all.

Edited 1 time(s). Last edit at 04/14/2015 12:44PM by ggherbaz.

Thank you so much, its on my best practices for now on.