Version 2

This adds 0.5mm to the outside diameter and tightened the grip on the funnel. It is essential to print this version out of filament that will flex and snap into place, otherwise you run the risk of cracking the ears which will cause the cover to pop off during retraction. The interference (grip) is significantly higher than version 1 and is significantly harder to install. I typically start at the front (towards the filament) and push the clip back on at an angle. I ended up printing mine out of Polymaker CoPA with a 0.2mm nozzle at 0.1mm layer height. Printed it at 295/45c and used Magigoo PA for bed adhesion.

https://us.polymaker.com/products/polymide-copa

Background:

This is technically a remix to several Bambu Labs AMS feeding funnel button covers. I personally didn't care for the aesthetics, logo/images on the button or bulkiness of the existing covers that wrap around the button itself so I ended up modeling this one from scratch. I also wanted something more wear-resistant than just PTFE (don't worry, I added a PTFE tube version for everyone else).

I first 3D scanned a feeding funnel to begin the reverse engineering process. Once modeled, I was able to perfectly match the contours of the funnel to truly give you a “perfect” fit. I added in some clearances and engineering practices for plastic design to give a perfectly fitting button cover with extra wear-resistance properties.

There are crush ribs on the bore for the bushing/ptfe so it creates a tight press fit. That being said, I was able to press fit the parts by hand.

Print Settings:

• Print in Nylon (needs to be able to flex and snap into place). ABS/ASA, PETG may work but Nylon is the best material for this print. You also need to print hotter (typically 10-20c hotter than default settings) to get good layer adhesion as the wall of the clip is very thin. If you don’t not have good layer adhesion, you run the risk of cracking and having the cover getting pulled off when retracting.

Purchased Components:

Drill Bushing Version:

• Drill Bushing - 5mm OD x 2.5mm ID x 6mm Overall LG, Flanged, 4mm Insertion LG, 2mm Flange Length
• KIPP: K1022.A0250X06
  https://www.kippusa.com/us/en/Products/Machine-Fixture-Components/Drill-bushings/K1022-Drill-bushings-flanged-DIN-172/K1022-A-Drill-bushings-flanged-DIN-172-style-A.html
  or
  https://www.kipp.com/gb/en/Products/Operating-parts-standard-elements/Machine-and-fixture-components/Drill-bushes/Drill-bushes-flanged-DIN-172/Flanged-drilling-bush-DIN-172-Form-A.html
• McMaster: 96977A137
  https://www.mcmaster.com/96977A137/

PTFE Version

• 4mm OD x 2.5mm ID (some like to keep it long so it wraps partially around the spool to help hold the spool down during retraction)