K2 Plus Complete Extruder Cover Replacement

UPDATE:

02.2026 - After a few months of Printing everything from PLA to PPS, it is holding up great. Ive had the sensor arm get stuck about 3 times, had to unbolt it, gave it a nudge and it snapped back forward, increased the clearance by 0,1mm for the .step file.... on that note I uploaded a step file for custom visual designs or remixes.  Kindly Id ask that remixes arent uploaded and for personal use only. If you have technical improvements, message me and I can upload them here or approve the remix. I know its not quite open source, but it has been a ton of work and Im not quite ready yet to let it go completely.

09.2025 - After a few more tweaks of V1.1 (No Sensor testing) and V1.2 (No Cutter Testing) this is the latest and likely final version V1.3. 

Everything worked perfectly during a trial benchy with PLA. Long term and high temperature printing still need to confirm long term usability

You will need the following: 

Tools:
2.0mm Drill bit
1.3mm Drill bit
1.0mm Drill bit
Tweezers
A needle
Superglue - to secure magnet

Parts:
2x3x10mm Magnet - can be sourced from old OEM cover
M63zz Bearing - can be sourced from old OEM cover
Filament sensor mechanism - must be sourced from OEM cover
M3 3mm threaded insert - For tensioning screw
2x M3 30mm screws

Print settings:
0,2mm Strength preset
Tree support: ON
Support on Buildplate Only: 

Support only the Filament Cutter floating area.
It is not necessary to support the gap next to the extruder gear - it is just for cleaning access 
If you print a Logo version, no support is needed for the Logo.
 

I recommend printing a test piece of the BSP and M10 variant, as both couplings exist but the M10 variant has become more common.

I recommend printing it in PPA-CF or PPS-CF in order to avoid creep.  If you do not want to buy a whole roll of the stuff just for one cover, and live in the EU, feel free to contact me and I can print you one at cost price + shipping.  Mine is printed out of PPS-CF

The holes for the filament path, the “filament sensor arm" shaft hole and “filament sensor arm spring tensioning” hole are slightly undersize in order to drill the perfect diameter out with the listed drills.
You will need to make sure that all the debris is cleared and might want to shove a piece of PLA filament through the extruder with everything pre mounted in order to smooth out the path and check that everything is clear.

I would recommend ordering a spare cover as well, in case the tiny parts for the filament sensor get lost, so you are not stranded.  Once everything is up and running you can always keep one as a spare, but still have the benefit of being able to fix your current cover cheaply.

I would appreciate feedback and collaboration to ensure that this model is working flawlessly because I think it would be a real benefit for the K2 Community.  

Complimentary upgrade:

https://www.printables.com/model/1152328-k2-plus-extruder-manual-tensioner

But use a 10mm long spring instead.

The model was scanned with a Revo POP 3 and modelled in Fusion.