Bambu Lab AMS feed port saver (ceramic nozzle/PTFE tube dual-use)

Prioritize printing type B. If it's too loose, then print type A

For more variations, please download the STL and slice it yourself

This model was found on MakerWorld's international site, using a PTFE tube as an anti-wear protector for the filament feed port

Given China's specific situation, ceramic nozzles used in the textile industry are available on Taobao, offering high hardness, better wear resistance, and a very affordable price. Some models perfectly fit 1.75mm filament and have precise dimensions (as shown in the figures). You can find them by searching "绞线机陶瓷嘴" (twisting machine ceramic nozzle) on Taobao

Alumina has a Mohs hardness of 9. Glass fiber (around 7) cannot wear down alumina at all. The hardness of carbon fiber is unknown, and it might cause slight wear (unclear and not researched, but its structure is carbon nanotubes, similar to the crystal structure of diamond. Perhaps at small, near-molecular sizes, its hardness approaches diamond's Mohs hardness of 10? Like how short hairs can pierce skin but long ones cannot. It might still cause extremely slight wear to ceramic, which needs experimental testing). However, alumina is clearly much stronger than PTFE. For long-term use, even if the AMS's internal feed gears wear out, the ceramic nozzle will not. Therefore, overall, it's a permanent protector

The ceramic nozzle chosen here has a large outer diameter of 6mm, a small outer diameter of 3.9mm, an inner diameter of 2.3mm, a small cylinder length of 4.3mm, and a total length of 6mm. I learned about these dimensions from an author on this site, thanks Jamar
The PTFE tube mounting hole of the original model has been modified to enhance versatility. The mounting hole diameters are a 4.1mm through-hole and a 6.1mm large top recess, which can accommodate not only this ceramic nozzle but also a 4mm outer diameter PTFE tube, allowing for installation as needed

Type A and Type B differ slightly in size, mainly because there are two types of AMS buttons, one large and one small. It is recommended for AMS units purchased before January 2024 to try Type A first, and those bought later to try Type B. It is best to print one of each and test them before installing the ceramic nozzle

Friends who can access the international site, please support the original authorAMS Feeder Funnel Saver Protector Filament Guide by eds_3d_shop - MakerWorld, he has improved several models

This is my first time posting a model. I'm unsure if it's compliant to release a modified model like this. If there are any issues, please leave a comment

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←0.12mm layer height

I found printing defects at the front of the mounting hole, which needed trimming with a knife after printing. I tried printing with a 0.2mm layer height, but the problem persisted at that location. However, I also found another interesting result: the aesthetic difference between 0.2mm and 0.12mm layer height prints is not significant, both are usable, so setting it to 0.12mm layer height is not a necessary operation, set it as needed

←0.2mm layer height

Adding supports and adjusting the threshold angle to 30 degrees might improve it. However, I don't like supports and am trying to figure out a better way to print it without them. I will update when I have a solution

------------November 26, 2024--------------

←AMS feeder protector - Type A/B

Upon inspection, there are many sharp corner toolpaths at this location. It is speculated that with such small, outward-pointing sharp corners, heat accumulation occurs, softening the filament due to high temperatures, leading to severe overhangs and a much worse actual print compared to what the slicer shows. The model has been modified for this area, with slightly altered mounting hole shapes to eliminate sharp corner toolpaths and create short bridges. The actual test results will be attached later. This corresponds to the "- No Overhang" version
The original version has a more perfect appearance and can be used with resin printers, so it is still retained

←AMS feeder protector - Type A/B - No Overhang

---------November 26, 2024 afternoon------------

The ideal is stark. After modifying the model, without supports, there are still terrible overhangs. Although slightly better than before, I'm still not satisfied and do not recommend printing it. Ultimately, I suggest adding supports to print the original model, damn it. Modifying other people's models is still frustrating; I'll have to design my own when I get the chance

←The improved model is better than the original without supports, but the improvement of the mounting hole makes it not tight enough, it can be glued. I will not modify this model further; in the future, if I create a model I believe is better, I will share it with everyone.
 

The original author also has another flat version, which I've made some changes to, but it still requires supports. I'm sharing it with everyone here.

February 13, 2025
Press the ceramic ring vertically with a soldering iron to make it flush with the surface and fit more securely