AMS Hub for A1/A1 mini - Fix feeding error

AMS Hub for A1/A1 mini - Fix “Unable to Feed Filament” error

This simple 3D printed part solves the common “Unable to feed filament” error that occurs in the AMS Hub on A1 printers which is connected to AMS 2 PRO, AMS, AMS HT.

The problem usually occurs when the filament enters the AMS Hub slightly bent (which is always the case because it is wound on a spool), which causes the error. 

The main symptom of this bug is:

When the filament enters the AMS Hub, the movable upper part with single PTFE connector moves to its highest position, and after a short moment the AMS module pulls the filament back to try passing through the AMS Hub again. After several attempts, the “Unable to feed filament” error appears.

What this part does

• guides the filament into the correct position
• improves reliability during filament changes
• slightly increases the spring pressure in the AMS Hub mechanism, improving filament guidance
• eliminates random feeding errors

Print recommendation

• I recommend printing this part in PETG, as it is more resistant to wear and temperature than PLA and better suited for long-term use inside the AMS Hub
• No support needed

Tested materials

This part has been tested with PETG, PLA, and TPU for AMS.

Recommendation

For best results and long-term reliable operation, I recommend combining this part with the following model, which reduces mechanical load on the 3D printed part and minimizes the risk of material fatigue and cracking.

Updated model

After several user comments and feedback, I have added a modified version based on the current print profile.

This updated model (labelad Modified in print profile) does not include the small ring that caused issues for some users. However, I still recommend printing the original model first, as it provides better and more reliable filament guidance into the PTFE connector. If you experience issues with original model, I recommend printing the modified version or carefully adjusting the original version with pliers.

Notes

• no printer modification required
• easy to install and remove

Assembly tutorial

Disclaimer

• The use of this part, any printer modifications, and all related operations are done at your own risk
• This is not an official solution or fix from Bambu Lab