I got tired of babysitting my Bambu A1 Mini every time it needed the External spool in a multi-filament print. So I built a fix.
Hi All,
Every time my print needed a 5th color or standard TPU in the mix, the printer would pause and just sit there waiting for me to manually feed and retract the filament. For a printer that automates everything else, it felt like a glaring gap.
So I spent the last several months building the ASR 5th Wheel, an auxiliary filament management device that mounts directly to the X-axis motor housing and moves with the gantry.
Hereās what it does:
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Detects filament insertion and autoloads
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Maintains filament tension continuously during printing using a Hall effect sensor
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Receives Feed and Retract commands over WiFi, triggered automatically by MacroDroid responding to Bambu Handy notifications
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Handles the entire filament change without any user interaction
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All of this without physically connecting to the expansion ports on the printer
Iāve run it through 1000 consecutive automated cycles with all types of filament my Mini can use without a single error.
The hardware is ESP32-based with custom firmware I wrote specifically for this application. The enclosure is 3D printed for now but Iām working toward a more polished production version.
Iām not selling anything yet, just gauging interest from the community before I take the next step. If this is something youād want for your own setup, drop a comment or follow along. Iāll be sharing updates here as development continues.
Happy to answer any questions about how it works.
- Advanced Signal Research, LLC Follow along at asr5thwheel.com -
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Does it work with TPU and/or PEBA.
Overture HS TPU works just fine. But my goal is to have it work with softer standard TPU. My print bed is currently occupied with a V2 modification of the Hall mechanism and the housing that I made after spending a day troubleshooting the standard issues. Iāve got a new firmware ready to got too that tweaks a few of the tolerances to made the unit more responsive.
Iāve never printed PEBA. Do you have a recommendation for a particularly difficult one that I can get for my prototype testing?
Iāll keep you posted on the outcome of the V2 Hall mechanism.
In my experience, PEBA is easier to print that TPU.
Got it. So if I can get Regular 95A to work, it should be fine. Iām going to grab a spool of PEBA anyway, just to put it through the paces.
That is my experience.
PEBA 90A for example is far easier than TPU95A to feed, print and everything else.
PEBA is a good material.
I have had good experience with SainSmart PEBA 90A High Rebound if you fancy a recommendation.
2 Likes
So the answer on TPU is; Yes, not a problem. The V2 Hall Buffer and revision of the firmware worked great. I set this printing before I stopped for the night last night and was very happy to see it this morning.
The Overture Space Gray PETG was in position 1 of my AMS Lite and the Overture Std Black TPU was on the ASR 5th Wheel. The test is only 10 filament changes, but it is perfect and the bonding of the PETG and TPU is strong and flexible. Iāll be running it through 100 filament swaps today, but donāt expect any issues.
I may have misunderstood the reach of this yesterday.
Your latest post implies it performed the swaps between two different materials while you slept.
Does you solution add this as a āfifthā spool of an AMS?
Fully automated, or have I got all confused?
It is great to see them both becoming fast friends.
That is exactly what it does. That is why we are calling the product ā5th Wheelā. It does not connect to the printer with a cable but rather responds to prompts in Bambu Handy. That way, hopefully, we will not have to deal with interfering with any of Bambuās proprietary Bambu Bus communication protocols. Here is a print I made using the ASR 5th Wheel that has about 140 hours of unattended print time in it. It was printed in 5 colors all fully automated; Bambu PLA Metal Gold, Bambu PLA Matte Ivory White, Bambu PLA Matte Charcoal, Bambu PLA Silk+ Gold, and Bambu PLA Silk+ Silver. (The mouse is for scale)
1 Like
Absolutely brilliant.
Remember, there are two other models, the A1 and the A2L.
I have the A1 mini & A2L from this series, two of my six BL printers.
Something like this for feeding TPU would be a great addition to my P1S and four slot AMS, if it could be made to work with the P1S.
I feel your pain. I didnāt know the AMS Lite would not be able to handle TPU when I bought it. After many hours of R&D I finally got modifications done on 2 of the four slots so that I could at least run a couple different brands of HS TPU on it. All I own right now is an A1 Mini, so I am not familiar enough with the AMS for the P1S. I did however use one of the first stage motors for that AMS in the V1 model of my ASR 5th Wheel. I wanted it to handle TPU, so I applied the same mod to it that I did to my AMS Lite and it was able to handle the TPU feed. I just donāt know what will happen when it gets to the second stage feeder and I donāt have one to experiment on. The trick is to replace the spring that holds the filament against the drive, but you have to experiment with different tensions.
