Printed Solid filament guide mark2

Filament guide

Filament rubs on my printed solid case and makes a really loud noise.  Here's a video showing the problem: https://imgur.com/a/Bv0gyx9 (also includes video of my mark 1 design). 

This model replaces the clear acrylic top that comes with the printed solid enclosure. It holds a PTFE (aka Teflon) bowden tube in place so the filament glides smoothly and doesn't rub on anything (no more noise).

Parts

• 1 - PC4-M10 coupler (not the smaller PC4 used in the old design)
• 1 - M10 nut
• 1- Bowden tube
• 2 - Zip ties
• Threadlock or other glue

I got the tube and coupler from this kit https://www.amazon.com/gp/product/B086YPDHMF/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1. The M10 nut was harder to find. If you can, prefer a “thin” nut over a full-sized one.

Coupler and nut assembly

Thread the nut on the coupler and put some thread lock on it. This is needed because the PC4-M10 coupler doesn't have that many threads, and it doesn't engage with a regular M10 nut very well.

The nut is used to keep the coupler in place. The coupler only bites into the PTFE tube in one direction, so it must be face-down in the final assembly.

Final assembly

• Screw the baseplate into the top of the printed solid enclosure using the original screws and nuts.
• Drop the coupler and nut assembly into the hole on the top. The white part of the coupler should be face down
• Place the top square over the nut/coupler assembly and align the square holes
• Secure it down with zip ties (prevents the coupler assembly from being pushed out in the other direction)

Once installed, insert the PTFE tube from within the enclosure. Cut to desired length.

Mark 2 - Upgrade details

The original design is found here: https://www.printables.com/model/217643-ptfe-adapter-for-printed-solid-enclosure.

What changed:

• Fixed hole alignment
• Switch from two small couplers to one large pass-through coupler
• Coupler no longer hangs into the case

The way the two PC4-M6 Couplers work on the original design meant there was an air gap between them. When I tried threading filament through, it would go through the first one fine, but get caught on the second. It was pretty annoying.

The dangling coupler in the original design also meant that when the printer is at maximum Z height the filament has to bend at an extreme angle and sometimes got kinked or stuck. 

1-month usage update

When printing really tall objects like https://www.printables.com/model/433507-clipboard-holster-for-out-the-door-reminders, my filament breaks with this guide. The design allows the tube to be removed, so when printing tall objects, remove the PTFE tube. 

Another alternative to this system could be to run the PTFE tube all the way to the head unit using a reverse bowden setup like the one pictured here https://www.prusa3d.com/product/original-prusa-enclosure-3/. However, I've not actually tried it, and don't know if that actually fixes the breakage problem. The downside of the reverse bowden is it makes removing and changing filament harder. I feel like the problem is ultimately that the distance from the top of the Prusa to the top of the enclosure is too short (I also have my machine on a paver inside the enclosure).