Z Jerk causing filament to stop feeding

It seems like all the sudden whenever my printer makes a Z Jerk move to prevent the filament from leaking out when moving to another position and not extruding, that when it trys to extrude again after making the zjerk move it cant push it back down. I pause the print and try to push it down and sometimes i cant even do it and have to take apart the whole extruder. If i put 0 for the Zjerk all is well, but i am left with strings everywhere(you know what i mean). I have replaced all the hardware on the wade extruder, including the hobbed bolt with the same result. I have a volcano head using .6mm, but it happens with my 1.2 mm as well. I tried cranking up the temp to 205 F with PLA (which is all im using) with the same result. Any input would be appreciated.

Using Cura btw.

Did you try to reduce the retraction length and speed up G0 moves?
It seems, you are pulling the molten filament into the cold zone and leave it there for too long. ( Z-lift and drop also adds time )
-Olaf

I did try to reduce the z jerk retraction length from 4mm to 2mm, 1mm and 0.5 with the same result. I tried slowing down the speed of the z jerk to 15 m/s when it was at 30m/s. those two things did not do a thing. What is G0 moves?

Im sorry I keep saying Z Jerk, its the RETRACTION under the ADVANCE menu in Cura. the mm/s and the distance. Sorry, im not sure if thats Z Jerk or not. Still a noob to this after 2 years.

I had a similar problem....solved with a 80mm fan over the step motors drivers controllers on main board.

The drivers are getting hot and causes strangers moves...

Cheers

Humberto Melo

Edited 1 time(s). Last edit at 12/12/2015 05:14PM by HumbertoMelo.

G0 moves are moves without extrusion. They should be fast to reduce oozing.
How much do you lift the Z axis in you retraction settings? 0.1-0.2mm are enough. Then use retraction length of 2mm and speed of 80mm/s.

If you still have problems with a blocked hotend, your PTFE tube inside the hotend is probably to tight or deformed ( from overheating? )
-Olaf.

Humberto, I dont think this is the issue because if i pull the filament up a little bit and try to push it back down immediately, with my fingers , it jams.
o_lampe, "how much do i liftt the Z axis in my retraction settings?" is that the "z hop" if so its defaulted to 0.0.
the length of the retraction was set to 4mm with 30mm/s speed. I have tried 2mm and 0.5mm and also taking the speed down to 15mm/s with no improvement.
Maybe it it set to too low of a speed on my retraction?
Also, the Volcano hot end i am using does not have a PTFE tube inside. Its all metal with a fan on the outside to keep it cool.

I was doing some more searching and found this quote in the E3D-V6 (volcano head) troubleshooting guide. "Connecting the hotend fan to the “Fan” output on an electronics board, which is software controlled and should be used for print cooling, not for a hotend fan"
And in the below diagram I have the fan hooked up to the pins labeled "extruder fan".
Should it be hooked up to the one labeled "print fan?" or D9?
[i.imgur.com]

Edited 1 time(s). Last edit at 12/14/2015 02:25PM by psi3000.

What you labled extruder fan is actually just 12V. Yes, the fan of the extruder should be always on.Only the fan cooling the printed parts need to be controllable.
The RAMPS does not have dedicated fan connectors for this, but you can reconfigure D9 (second extruder heater) for the purpose.

---

[www.bonkers.de]
[merlin-hotend.de]
[www.hackerspace-ffm.de]

so do i have it plugged into the wrong one? you said its just a 12v i have it plugged into but shouldnt that be good on a 12v fan? Or do i need to reconfigure D9 like you say?

Imo you did it right, the fan on the E3D needs to be connected directly to 12V.

Over all your problem sounds as if the hotend itself causes it. You did the right thing by reducing retreact. With a non Bowden setup you usually don't need more than 1mm and you should do it fast to prevent oozing as much as possible.
I don't have the volcano, i only ever tried the normal v6. If the volcano is similar you realy have to make sure that there is no gap between the nozzle and the tube that screw into the heater. If there is a gap this blockage could be the result.
Also all metal hotends are not the best choice for PLA. PLA tends to stick very good on hot polished steel. PTFE hotends work in general better with PLA.

---

[www.bonkers.de]
[merlin-hotend.de]
[www.hackerspace-ffm.de]

I have never had this problem in over a year of printing. I have even used the Volcano for about 6 months with no issues like this. I dont know what changed. I even tried a new thermister with the same result. Ill try the thermal paste tonight on the top part like i have seen in some other suggestions.
thanks for all the help!

Maybe your filament has become thicker?

Quote
psi3000
Ill try the thermal paste tonight on the top part like i have seen in some other suggestions.
thanks for all the help!

Thermal paste? Please do yourself a favour and don't let it anywhere near the hotend. Thermal paste is meant as a thermal bridge for cooling purposes int teh <100°C range. It will not withstand the temperatures used for printing. At best you get a mess, at worst you get real damage.

---

[www.bonkers.de]
[merlin-hotend.de]
[www.hackerspace-ffm.de]

Quote
Srek
Thermal paste? Please do yourself a favour and don't let it anywhere near the hotend. Thermal paste is meant as a thermal bridge for cooling purposes int teh <100°C range. It will not withstand the temperatures used for printing. At best you get a mess, at worst you get real damage.

Just for the record, Z5 is good to 300C

[www.deepcool.com]

thanks for the warning Srek. I used Artic 5 silver thermal grease good up to 180 deg. I only put it on the cooling part, which is recommended by the manufacturers of the Volcano head. I am guessing it wont get nearly this hot as they say to use standard thermal grease.