Neptune 4 Pro/Plus/Max Front Spool Mount + Reverse Bowden Upgrade

UPDATE 6/19/24:

Bowden tube now only inserts to the depth of the PC4 - then stops and can't slide in too far. 

Curvature of the channel was lessened - no more binding.

Filament aligns with the bowden tube and slides in easily without getting hung up.

PC4 threads into the block a little deeper to allow for more print height.

Reoriented model to sit on build plate correctly so you don't have to.

Update 5/22/24:

I've added my remix of the printhead mount for the PTFE connector - just finger tighten and snug with wrench.

This is a remix. Thanks to @HalfManBear for creating the original. He has some other great Neptune designs so go check him out. Also thanks to @Dash for simplifying the printhead mount - I love simple solutions!

I plan to build a printer enclosure at some point and this mount seemed like the logical choice. I've also been working on a reverse Bowden upgrade and tested out some other models but none of them were quite what I wanted so here we are.

The original description by HalfManBear lists some parts you'll need:

Uses original M4 Hex screws for initial mounting.

Requires 2x M4 Nuts & 2x M4x25mm bolts

I'm using the N4 Plus and this is working perfectly. For the full upgrade bennies you'll also need a couple of PC4-M10 connectors and some Bowden tubing. I got my tubing and connectors as a kit from Amazon. (Affiliate link)

Mount PC4 to printhead:

Using the included printhead mount you can affix one connector to the stock printhead - also works with a custom shroud. No hardware needed for this - on top of your printhead there's a small collar where the filament enters - just apply a very small amount of super glue around the outside of this collar and press fit the mount on. Once the glue dries thread on the PC4. 

Mounting Spool Holder:

I found that the connectors thread in perfectly (just finger tighten to start threads). Your mileage may vary depending on your printer settings. I gently snugged them up with a wrench. I purchased the two M4 nuts and M4x25mm bolts for the spool mount at my local hardware. It's a little tricky to get the threads started on these but once you do everything fits together nicely and holds solid. A small length of PTFE can also be inserted to the top of the mounting block if you like.

Optional:

You can see from the pictures that I also modified the filament runout sensor. This isn't a requirement - just how I did it. The brass inserts that come with the sensor wear out quickly from friction. Check yours and you'll see a groove worn into the brass. I used a drill bit that was slightly smaller than the brass inserts and slowly drilled into them. This heats the brass up until it pops out of the sensor housing. I then cleaned up the holes with a slightly larger bit but if you attempt this mod be careful not to drill any deeper than the existing hole. Next I inserted a couple pieces of vinyl air hose into the holes where the brass fittings were (cheap aquarium bubbler hose). The hose pieces fit snug and a little super glue ensures they stay put. As a bonus the PTFE Bowden tubing fits perfectly into the air hose. 

Filament:

I recommend PETG, ASA, or ABS. This is a pretty solid model and gets bolted down so you could probably get away with PLA but it might deform - especially in an enclosure.

My Print Settings:

I am currently using OrcaSlicer 2.0, PETG filament, and a 4mm nozzle.

Orient the spool mount so the top sits on the build plate to eliminate need for support.

Layer height: 0.2

Line width 0.5

Arc fitting: check

Elephant foot: 0

3 walls

10% infill - 3D Honeycomb

Infill/wall overlap 33%

SPEED:

First layer: 30mm/s

First layer infill: 60mm/s

glue stick

I have a few remixes and some of my own models (not yet released). Some of my mods have greatly improved the print quality on this printer (Neptune 4 Plus). You might catch a glimpse of a couple in the photos. This remix is my first post to Printables and I will be sharing more soon so please follow and stay tuned :) I try to design models that are easy to print and assemble, improve print quality/functionality, and avoid the need for extra hardware if possible. If I test a model and it's not working properly I'm not going to share it. Feel free to send me a message with questions or leave a comment. These are the spool holders I'm using and they're freeking perfect IMO.

I've added a centralized passthrough hole for a Bowden tube and threads to accept a PC4-M10 connector.