K2 Plus PTFE Swingarm

Simple Prusa Swing-Arm modified to work with a K2 Plus. I did this so that I could print PPA-CF/PPS-CF without it breaking in the PTFE (mainly during initial purging/nozzle cleaning). The factory PTFE is too tightly ran and bends the filament too much to run these brittle filaments. You will need a Riser to attach this to, ideally a riser with a flat wall so you can attach it. Uses M3 nuts and bolts to attach it to the riser and a M4 bolt to attach the swingarm to the hinge.  I've included the .STEP file so you can modify it to you your liking. Import the step and split to objects to print. You need minimal supports just on the hinge portion, everything else will print flat on the bed. Print it out of PPA-CF for the best results I use 6 walls and 70% infil with 7 top and bottom layers so it was nice and stiff. To attach the PTFE guides I dabbed a bit of super glue on them after roughing the mounting surface then wrapped a few winds of electrical tape around them. You could also use a ziptie or print with supports as 1 pc. I also used super glue to affix the ptfe to the ptfe guides that mount to the swingarm. To get it out of the printer I just drilled a hole thru the riser but you can get as creative with that as you want, like a bulkhead connector so you can easily remove it if you need to. You want at minimum 14.5" of ptfe length when you measure from the last ptfe mount on the swingarm to the extruder connection. That's what I have found worked best.  From there I ran mine directly to my filament dryer I see no reason why this couldn't replace the original feed from the CFS but I haven't tried it. I pull the stock PTFE back to the rubber inlet on the printer while i'm using this. The spring is for returning the swing arm as well as stowing it out of the way for when you are using the stock ptfe, I tuck the ptfe for it behind the swingarm when i'm not using it.

You will need:

M4 Drill Bit to clean out hinge/swingarm hole and ptfe holder holes.

M3 Drill Bit to drill through riser to attach hinge/backplate

M4 tap to thread swingarm and hinge for return spring bolts (this is sufficient in my experience but you are welcome to drill it out and use a bolt+nut)

3x M3x15mm SHCS to attach hinge to riser

2x M4x10mm button head to attach return spring to swingarm/hinge 

1x M4x30mm SHCS or button head for hinge to swingarm

1x M4 Nylock nut for hinge bolt

1x 9/32 x 2" Extension Spring (commonly found in the Harbor Freight Spring Assortment Kit)

Be mindful of how high you mount it, the M4 bolt head can get close to the glass when you set it back down on the riser.

Added a shorter arm, i found after awhile the longer one with elevated chamber temps even with PPA the arm would creep over time and bend. the shorter one took care of it.