I print from a dry box for my Neptune 3 Max. The included filament runout sensor attaches to the top mounted spool holder.

This is a poor design in my opinion. The N3 Max is large enough without a top heavy spool mount. Additionally, I want to protect & guide the filament from the dry box all the way to the extruder.

Nothing else existed, so I created this model for the Neptune 3 Pro series. I'm assuming the runout sensor and the gantry dimensions are the same for the Pro & Plus as the Max.

No additional hardware needed (except for the PTFE fittings of course). This reuses the screws from the runout sensor & spool holder.

This model is sized for PC4-M10 PTFE fittings but it would be relatively simple to modify it for PC4-M6 fittings.

Notes:

1. Lid is optional. If you don't like the standoff sticking up, you can remove the OEM cover from the runout sensor. However if you want to sure the sensor will stay in place, then the lid is recommended.
2. No need for supports, just print with bottom on the build plate for the base & top on the build plate for the lid.
3. From a stress standpoint, any material should be fine. I printed in PETG as my printers live in the garage (and it gets hot!).