Cannot lock Nextruder idler with a idler-swivel - filament not pushed into nozzle
Hello,
I've just finished assemble of the MK4 Kit. Unfortunately my Nextruder idler cannot lock which leads to filament not being taken by gear (gear rotates but not move the filament into the nozzle). I'm not sure if that because of some misprint or maybe I've assembled something wrong - should I just grind down a marked fragment of the idler? I've attached full video below and a photo to better illustrate a problem.
I've also minor, second question - is it possible to align nextruder gear in that position (vertical)? In order to take out X axis I would need to break whole cable management, disconnect X motor plus nextruder cables, which seems to take a lot of time.
Best Regards,
Mateusz Dudek
For some reason my mp4 video cannot be placed here - link to it: https://storage.googleapis.com/prusa3d-content-prod-14e8-wordpress-forum-prod/2024/02/b2827961-signal-2024-02-29-233054.mp4
Best Answer by JoanTabb:
No pictures that I am aware of.
the Idler lever needs to be separated from the heatsink by a small gap, in order for the idler swivel, to be tensioned and latch. currently the idler lever is too close to the heatsink and there is no displacement of the idler swivel to cause tension in the springs
regards Joan
RE: Cannot lock Nextruder idler with a idler-swivel - filament not pushed into nozzle
I believe your idler lever is too close to the nextruder body when you try and latch it with the Idler swivel because the Planetary gear assembly (PG Assembly) is not in place. Please see step 7 and following steps in this guide
https://help.prusa3d.com/guide/5-nextruder-assembly_434014
Please also note that there should be a thin washer, on the shaft of the motor!
It is possible to assemble the planetary gearbox, with the extruder motor and Heatsink assembly mounted vertically on the X axis carriage.
the PG Assembly adapter is used to make assembly easier, however there is a need for a certain amount of wiggling backwards and forwards to align all of the components of the gearbox.
It will be easier, without the filament in the way.
regards Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
RE: Cannot lock Nextruder idler with a idler-swivel - filament not pushed into nozzle
1. The problem was the same when planetary gearbox was on place - but then it was hard to see when exactly it is blocking it to fully go into the nextruder
2. Thin washer was applied - it just sticked to gerbox part during disassembly, that's why it cannot be visible on a shaft 🙂
Is there any picture of a nextruder without gearbox and locked idler plastic part just to compare with mine?
I'll make some additional pictures, insert gearbox and then do another short movie.
RE: Cannot lock Nextruder idler with a idler-swivel - filament not pushed into nozzle
No pictures that I am aware of.
the Idler lever needs to be separated from the heatsink by a small gap, in order for the idler swivel, to be tensioned and latch. currently the idler lever is too close to the heatsink and there is no displacement of the idler swivel to cause tension in the springs
regards Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
RE: Cannot lock Nextruder idler with a idler-swivel - filament not pushed into nozzle
Edit time was too long and whole post with pictures went into abyss...
How it is possible? There's one hole in which goes socket set screw 3x25 & Tubular spacer 13.2x3.8x0.35 (Steps: 6 & 14 of the nextruder-assembly guide) so there's no option to change a space between it and the heatsink 😐
Unlocked
"locked" - in reality not locking anything
Gap 
Videos:
https://storage.googleapis.com/prusa3d-content-prod-14e8-wordpress-forum-prod/2024/03/b4e3ef5f-signal-2024-03-01-103237.mp4
https://storage.googleapis.com/prusa3d-content-prod-14e8-wordpress-forum-prod/2024/03/16d1d556-signal-2024-03-01-103156.mp4
RE: Cannot lock Nextruder idler with a idler-swivel - filament not pushed into nozzle
Thanks for the pictures, you still appear to be trying to activate the lever and swivel with vital parts missing.
from a distance it is difficult to see whether the swivel pivots far enough to trap the lever when the lever is in the correct position.
currently, the lever is too close to the heatsink.
when installed the large gear of the extruder h0lds the lever slightly further away from the heatsink, and the swivel needs to be tensioned by the springs to hold the lever in position, When the filament is inserted the lever moves further away from the large gear, adding additional tension.
Are the swivel components assembled correctly? are could the two side pieces be upside down?
regards Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
RE:
Problem solved - I was not aware that part need some force to be moved into side (Maybe grinding that 0.2 mm was also helpful? Not sure). You can see that marked gap from first picture on a second one - it has about missing 1mm - probably that's obvious and it was my stupid mistake.
Thanks a lot for the help, now I'm doing my first print and topic may be closed 🙂
Maybe it would be good to add note to the guide about checking if idler is locking properly with a picture of a fully locked idle?
Fully locked and working idler - now filament goes just well.
RE: Cannot lock Nextruder idler with a idler-swivel - filament not pushed into nozzle
And if you followed the assembly instructions exactly and installed the transmission first and then tried to lock the lever, you wouldn't have had to write here and it would have been fine.
RE:
@Miroslav.h4 - hmm? I did exactly as in the assembly guide, then I took out transmission/gear to see what's blocking the idler lever (also one cable was going out of it's cable channel but after fixing that problem persisted). Also that's why that forum subsection exists? 🙂
Have a good day and thanks for the hints!