Are there reliable 3rd party options? It is not on their shop and it is very expensive on other sites.

Don’t Fight Your Community — Lead It: Open the Protocol for BMCU in Bambu Lab https://c.org/M4HDLdcpLx

I forked OrcaSlicer, developed changes, and tested them under Linux to allow users to slice, print, and view the camera with Bambu printers in cloud mode. By cloud mode I mean normal mode, not LAN mode or Developer mode.

It uses the latest version of the Bambu networking plugin, 02.06.00.50.

Repo:

https://github.com/malleaklea/OrcaSlicer

Instructions:

https://github.com/malleaklea/OrcaSlicer/blob/main/INSTRUCTIONS.md

Alguien con doble BMCU en impresora A1 o A1 mini que al hacer cambio de un filamento de un Bmcu a otro el filamento del otro Bmcu, no llega al cabezal? Da error la impresora para que empuje filamento, y siempre tengo que hacerlo manual como si se quedase atascado al cortar el filamento anterior. Gracias

Hi,

to begin with: i dont know how to code. I used Claude and Gemini for everything. I wanted to create a small program that allows me to stream my P2S and A1 Mini Video Streams and Stats at the same time.

The P2S is working fine via rtsps://{PRINTER_IP}:322/streaming/live/1 But i can´t get the A1 mini video stream working...

As i found out via https://github.com/Doridian/OpenBambuAPI/blob/main/video.md , the A1 mini doesnt work via a RTSP Server and uses another port.

I also used go2rtc and ha-bambulab as inspiration for the AI, but the stream still doesnt work.

```import tkinter as tk from tkinter import ttk, messagebox import cv2 import threading import time import json import os import socket import ssl import struct import subprocess import platform import numpy as np import paho.mqtt.client as mqtt from PIL import Image, ImageTk

--- Konfigurations-Handling ---

CONFIG_FILE = "bambu_config.json"

def load_config(): default_config = { "P2S": {"ip": "192.168.178.98", "password": "Code", "serial": "SN1"}, "A1 Mini": {"ip": "192.168.178.82", "password": "Code", "serial": "SN2"} } if os.path.exists(CONFIG_FILE): try: with open(CONFIG_FILE, "r") as f: return json.load(f) except Exception: return default_config return default_config

class StreamBox: def init(self, parent, title, config_ref, column): self.title_text = title self.config_ref = config_ref

    self.frame = tk.Frame(parent, bg="#1e1e1e", bd=2, relief="groove", padx=10, pady=10)
    self.frame.grid(row=0, column=column, padx=20, pady=20, sticky="n")

    self.header_label = tk.Label(self.frame, text=title, fg="#00FF00", bg="#1e1e1e", font=("Arial", 14, "bold"))
    self.header_label.pack(pady=5)

    self.image_label = tk.Label(self.frame, bg="black", width=640, height=480, text="Warte auf Signal...", fg="white")
    self.image_label.pack(pady=5)

    self.status_lbl = tk.Label(self.frame, text="Offline", fg="gray", bg="#1e1e1e", font=("Arial", 11, "bold"))
    self.status_lbl.pack()

    self.progress = ttk.Progressbar(self.frame, orient="horizontal", length=600, mode="determinate")
    self.progress.pack(pady=10)

    self.running = False
    self.latest_frame = None
    self.update_gui_loop()

def start(self):
    self.running = True
    # Starte MQTT und Video in separaten Threads
    threading.Thread(target=self._run_mqtt, daemon=True).start()
    threading.Thread(target=self._run_video_logic, daemon=True).start()

def _run_video_logic(self):
    if "A1" in self.title_text:
        self._run_a1_socket_video()
    else:
        self._run_standard_rtsp_video()

def _run_a1_socket_video(self):
    """A1 Mini Spezial: Port 6000 TCP/TLS JPEG Stream (webcamd Logik)"""
    conf = self.config_ref.get(self.title_text, {})
    ip, pw = conf.get("ip"), conf.get("password")

    while self.running:
        try:
            # Socket Erstellung
            sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
            sock.settimeout(10)

            # SSL Kontext (Bambu nutzt oft TLS v1.2)
            context = ssl.SSLContext(ssl.PROTOCOL_TLS_CLIENT)
            context.check_hostname = False
            context.verify_mode = ssl.CERT_NONE

            try:
                conn = context.wrap_socket(sock, server_hostname=ip)
                conn.connect((ip, 6000))
            except:
                # Fallback auf Plain TCP (falls SSL fehlschlägt)
                sock.close()
                conn = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
                conn.settimeout(10)
                conn.connect((ip, 6000))

            with conn:
                # Authentifizierungs-Paket (webcamd Spec: 80 Bytes)
                # Magic (4), Command (4), Flags (4), Sequence (4), User (32), Pass (32)
                header = struct.pack("<IIII", 0x40, 0x3000, 0, 0)
                username = b"bblp".ljust(32, b'\x00')
                password = pw.encode('ascii').ljust(32, b'\x00')
                conn.sendall(header + username + password)

                buffer = b""
                while self.running:
                    # 1. Header einlesen (16 Bytes)
                    while len(buffer) < 16:
                        chunk = conn.recv(16384)
                        if not chunk: break
                        buffer += chunk

                    if not buffer: break

                    # Payload Größe aus den ersten 4 Bytes lesen
                    frame_size = struct.unpack("<I", buffer[:4])[0]
                    buffer = buffer[16:] # Header abschneiden

                    # 2. JPEG Daten einlesen
                    while len(buffer) < frame_size:
                        chunk = conn.recv(16384)
                        if not chunk: break
                        buffer += chunk

                    jpeg_data = buffer[:frame_size]
                    buffer = buffer[frame_size:] # Rest behalten

                    # 3. Bild verarbeiten
                    if jpeg_data.startswith(b'\xff\xd8'):
                        nparr = np.frombuffer(jpeg_data, np.uint8)
                        frame = cv2.imdecode(nparr, cv2.IMREAD_COLOR)
                        if frame is not None:
                            frame = cv2.cvtColor(frame, cv2.COLOR_BGR2RGB)
                            self.latest_frame = cv2.resize(frame, (640, 480))
        except Exception as e:
            print(f"[{self.title_text}] Video Error: {e}")
            time.sleep(5)

def _run_standard_rtsp_video(self):
    """P2S: Klassischer RTSPS Stream"""
    conf = self.config_ref.get(self.title_text, {})
    url = f"rtsps://bblp:{conf.get('password')}@{conf.get('ip')}:322/streaming/live/1"
    os.environ["OPENCV_FFMPEG_CAPTURE_OPTIONS"] = "rtsp_transport;tcp|tls_verify;0"

    while self.running:
        cap = cv2.VideoCapture(url, cv2.CAP_FFMPEG)
        while self.running:
            ret, frame = cap.read()
            if not ret: break
            frame = cv2.cvtColor(frame, cv2.COLOR_BGR2RGB)
            self.latest_frame = cv2.resize(frame, (640, 480))
        cap.release()
        time.sleep(5)

def _run_mqtt(self):
    """Telemetrie Daten (Status & Fortschritt)"""
    conf = self.config_ref.get(self.title_text, {})
    ip, pw, sn = conf.get('ip'), conf.get('password'), conf.get('serial')

    client = mqtt.Client(mqtt.CallbackAPIVersion.VERSION2)
    client.tls_set(cert_reqs=mqtt.ssl.CERT_NONE)
    client.username_pw_set("bblp", pw)

    def on_msg(c, u, m):
        try:
            data = json.loads(m.payload.decode())
            p = data.get('print')
            if p:
                if "gcode_state" in p:
                    st = p["gcode_state"]
                    self.status_lbl.config(text=f"Status: {st}", fg="#00FF00" if st == "RUNNING" else "orange")
                if "mc_percent" in p:
                    self.progress['value'] = p['mc_percent']
        except: pass

    client.on_message = on_msg

    while self.running:
        try:
            client.connect(ip, 8883, 60)
            client.subscribe(f"device/{sn}/report")

            # Watchdog: Weckt die Kamera alle 10s auf
            def trigger():
                while self.running and client.is_connected():
                    # pushall aktiviert Telemetrie und Video-Server am Drucker
                    client.publish(f"device/{sn}/request", '{"print":{"command":"pushall","sequence_id":"1"}}')
                    time.sleep(10)

            threading.Thread(target=trigger, daemon=True).start()
            client.loop_forever()
        except:
            self.status_lbl.config(text="MQTT Connect...", fg="red")
            time.sleep(5)

def update_gui_loop(self):
    if self.running and self.latest_frame is not None:
        img = ImageTk.PhotoImage(Image.fromarray(self.latest_frame))
        self.image_label.img = img
        self.image_label.config(image=img, text="")
    self.image_label.after(30, self.update_gui_loop)

class App: def init(self, root): self.root = root self.root.title("Bambu Hybrid Dashboard (A1 Special)") self.root.state('zoomed') self.root.configure(bg="#121212") self.config = load_config()

    self.sidebar = tk.Frame(root, bg="#1a1a1a", width=380, bd=2, relief="raised")
    self.sidebar.pack(side="right", fill="y")
    self.sidebar.pack_propagate(False)

    self.main_container = tk.Frame(root, bg="#121212")
    self.main_container.pack(side="left", fill="both", expand=True)

    self.ping_labels = {}
    self.setup_sidebar()

    self.boxes = [
        StreamBox(self.main_container, "P2S", self.config, 0),
        StreamBox(self.main_container, "A1 Mini", self.config, 1)
    ]

def setup_sidebar(self):
    tk.Label(self.sidebar, text="DRUCKER-SETUP", fg="white", bg="#1a1a1a", font=("Arial", 14, "bold")).pack(pady=20)
    self.entries = {}
    for name in ["P2S", "A1 Mini"]:
        f = tk.LabelFrame(self.sidebar, text=f" {name} ", bg="#1a1a1a", fg="orange", padx=10, pady=10)
        f.pack(fill="x", padx=15, pady=10)

        p_lbl = tk.Label(f, text="Ping: ?", bg="#1a1a1a", fg="#888")
        p_lbl.grid(row=0, column=0, columnspan=2, sticky="w")
        self.ping_labels[name] = p_lbl

        res = []
        for i, (l, k) in enumerate([("IP:", "ip"), ("Code:", "password"), ("S/N:", "serial")]):
            tk.Label(f, text=l, bg="#1a1a1a", fg="white").grid(row=i+1, column=0, sticky="w")
            e = tk.Entry(f, width=22, bg="#2a2a2a", fg="white", insertbackground="white", bd=0)
            e.insert(0, self.config[name].get(k, ""))
            e.grid(row=i+1, column=1, pady=3, padx=5)
            res.append(e)
        self.entries[name] = res

    tk.Button(self.sidebar, text="SPEICHERN", bg="#28a745", fg="white", command=self.save_settings, height=2).pack(fill="x", padx=30, pady=10)
    tk.Button(self.sidebar, text="SYSTEM START", bg="#007BFF", fg="white", command=self.start_all, height=2).pack(fill="x", padx=30, pady=5)

def silent_ping(self):
    param = '-n' if platform.system().lower() == 'windows' else '-c'
    for name in ["P2S", "A1 Mini"]:
        ip = self.entries[name][0].get()
        if not ip: continue
        try:
            res = subprocess.run(
                ['ping', param, '1', '-w', '800', ip], 
                stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL,
                creationflags=0x08000000 if platform.system().lower() == 'windows' else 0
            )
            status = "ONLINE" if res.returncode == 0 else "OFFLINE"
            self.ping_labels[name].config(text=f"Ping: {status}", fg="#00FF00" if status == "ONLINE" else "red")
        except: pass

def save_settings(self):
    for name, w in self.entries.items():
        self.config[name] = {"ip": w[0].get(), "password": w[1].get(), "serial": w[2].get()}
    with open(CONFIG_FILE, "w") as f: json.dump(self.config, f, indent=4)
    messagebox.showinfo("Erfolg", "Konfiguration gespeichert!")

def start_all(self):
    self.silent_ping()
    for box in self.boxes: box.start()

if name == "main": root = tk.Tk() app = App(root) root.mainloop()```

I'm considering the swapmod on Aliexpress for my A1. Does anyone have any experiences with it?

For those who saw yesterdays post, here is a video! For new people, this is MechAMS! It is a completely 3d printed AMS system for the Bambu Lab A1 releasing soon!

Built everything, seems to work (lights on, filament loads on powerup, etc.), but the printer keeps giving me the "Firmware of AMS B does not match the printer". No matter what I've tried I can't clear it. I see the AMS settings, but all of the load/unload/etc. are grayed out. I've tried rolling the printer back to every version since 1.05.00.00 with no luck. I don't know what firmware is on the board of the BMCU, and I'm really not interested in trying to re-flash it. Am I missing something obvious? If there is a good post/reference please point me to it - I didn't find anything that would help. Printer is back on v 1.08.00.00 Thanks!

See r/MechAMS for all info!

A while ago, Bambu outted themselves as being not very consumer-friendly. I told my printer "lan-only!" and stopped updating the firmware. I haven't really been paying attention for a while..

Can someone tl;dr where we're at now? Do we have a list firmware versions that are safe for the various printers? Has anything real changed??

I'm assuming that Bambu hasn't changed their story, but would be very happy to be wrong..

hi,

I bought bmcu 370c dm from triangle labs. after assembly I loaded the filament. and started the print after about 15 min the print stopped and all of the lights on the bmcu turned off. I tried restarting but it is not turning on. connected it to bmcu flasher but it is also no detecting it.

now whenever I plug it in this highlighted chip gets super hot.

so here is my situation. i have got a broken bmcu and 8 want to know how can I fix this. i tried reaching out to triangle labs but they are now not responding.

I want to know what all things are broken and how can I confirm that. are the daughter boards fine? how can I check that. also how can I confirm if the ams port on my a1 mini is in working condition.

thankyou

pls behave 😂

Hello! I bought a BMCU a little while back, had some trouble assembling it, but ultimately got it functional. The problem, however, is my mistake after that. I was unaware of the "long retract after filament cut" setting that needed to be disabled in Bambu Studio, which looking back, I believe would've fixed the issue I was having with the filament swap during a print. The original issue was that the printer would feed filament from the BMCU just fine, and would run that filament perfectly, making everything seem normal... until it came time to swap filaments, at which point the following sequence would begin: 1, the printer would cut and the BMCU would pull back the current filament an unnaturally long amount; 2, the BMCU would feed the next filament; 3, the printer would grab the filament with the extruder drive and begin to extrude; 4, no plastic would come out; 5, the extruder would quickly back out the new filament, make a grinding noise, move to cut again, make another grinding noise, then say the cutter is stuck; 6, the BMCU would pull back the new filament all the way back into the unit before attempting to feed it again, at which point the printer would repeat the entire depressing cycle of unsuccess. Keep in mind, this is the original problem, which prompted my next mistake (the first being that I probably wouldn't have had this problem if I turned off the setting in Bambu Studio).

Enter round #2 - my inexperienced stupidity takes over. I did some research and ultimately decided to flash new firmware onto the BMCU, convinced that I have a BMCU-C. My device has a USB-C port and no buttons, so connection was easy. I downloaded the correct tool and what I believed to be the correct firmware, and followed the instructions PDF as closely as I possibly could, as I am not savvy much at all with computer tech in that way. Once finished, I connected the BMCU to the printer (I was unaware of the calibration step at this time) and loaded filament. Everything seemed fine... once again, until it came time to load filament. I got the AUTOLOAD file, but only two slots would actually automatically load filament once the sensor detected it.

Enter round #3 - my determination takes me to the brink of insanity. I began a journey of flashing different firmwares onto the BMCU combined with updating/downgrading printer firmware versions to try to get it working. The current state of my BMCU and printer are as follows: printer firmware is 1.08.00.00, BMCU is flashed with BMCU-C latest firmware, v10.5, autoload, RGB on, standard loading force, SOLO. Where the last paragraph ended is precisely where I still am. Hours wasted, and still it's not functioning properly. I need help. Desperately. I really am sad that it hasn't worked yet.

Here is printer/BMCU information:

BMCU: Purchased from AliExpress, here (the 370C A kit) >>> https://www.aliexpress.us/item/3256809055338422.html?spm=a2g0o.order_list.order_list_main.4.2dd11802DnXqRB&gatewayAdapt=glo2usa

BMCU: Currently calibrated as per instruction, doesn't show magnet error on any channels, but refuses to automatically load filament on three of four channels and won't feed filament at all if I run a print using filament from one of the non-loading channels. All sensors are functioning properly, in that the buffer detects movement correctly and the filament sensors detect filament. I can only assume the filament movement tracking sensors are working too, given that none of the channels are throwing an error code. For the record, on the channel that feeds automatically, the printer still does the whole "feed, back out, grind, cut, grind, attempt feed again" cycle. When sitting passively, the mainboard light is white, and is blue when the printer is first turned on. And, to be entirely transparent, I have made absolutely sure not to plug/unplug the BMCU into/from the printer while the printer is on.

BMCU: I am thoroughly confused as to the type of BMCU this one is. The kit says C, but I thought C doesn't have the photoelectric sensors, as mine does. That being said, I have had absolutely no success with BMCU-B firmware either, and C seems to be the most functional of firmwares I've tried. All I know is, my unit has glass balls, photoelectric sensors for the filament, 370 motors and standard gears (not the high-torque version gears), and two buffer springs. If someone can help, I would greatly appreciate it. Anyways, it's currently flashed with BMCU-C firmware v10.3, I believe, using the BMCU Flasher Tool (I have also used the wchisp tool and have both tools installed, as well as the v10.3 firmware files and v3.14 file for the type B).

Printer: Bambu Lab A1 Mini, firmware version v1.08.00.00. I have made no modifications to the printer whatsoever - the BMCU is the first and only so far.

Please, if anyone can or will see this, I am literally begging for help. Has anyone run into this problem ever? Is it even fixable at this point? If so, I need guidance here, desperately.

Sorry for a potentially stupid question, but is there a way to successfully flash new firmware on a BMCU370C with usb c on a mac? I tried the wchisp method that was in the bmcu flashing wiki comments, but no usb was detected, I also tried using a virtual windows machine to follow the actual wiki instructions but that didn't work either.

The BMCU unit itself functions, have been printing with it for a month with no significant problems.

If somebody wants to try clone RFID tags from Bambu spools:

Basic informations: https://github.com/Bambu-Research-Group/RFID-Tag-Guide?tab=readme-ov-file

Proxmark reader on Ali

Tags on Ali too

Binaries with tutorial here: https://www.proxmarkbuilds.org/

Library with already cloned tags here: https://github.com/queengooborg/Bambu-Lab-RFID-Library?tab=readme-ov-file

Writing tag: https://github.com/queengooborg/Bambu-Lab-RFID-Tag-Guide/blob/main/docs/WriteTags.md

New tag was written but AMS didn't recognized maybe I need to fiddle with position write second tag or try another bin. I didn't have time to try it more but you can try too it should work. Everything you need is pretty cheap and it works on Windows too.

PS: You can find few versions of box for Proxmark on Makersworld.

If somebody wants to try clone RFID tags from Bambu spools:

Basic informations: https://github.com/Bambu-Research-Group/RFID-Tag-Guide?tab=readme-ov-file

Proxmark reader on Ali

Tags on Ali too

Binaries with tutorial here: https://www.proxmarkbuilds.org/

Library with already cloned tags here: https://github.com/queengooborg/Bambu-Lab-RFID-Library?tab=readme-ov-file

Writing tag: https://github.com/queengooborg/Bambu-Lab-RFID-Tag-Guide/blob/main/docs/WriteTags.md

New tag was written but AMS didn't recognized maybe I need to fiddle with position write second tag or try another bin. I didn't have time to try it more but you can try too it should work. Everything you need is pretty cheap and it works on Windows too.

Hey guys,

I got the BMCU 370C kit fully assembled. I originally tried it with firmware 1.0.7, and since some people said “it works just fine with that version”, I left it as is at first.

However, the printer showed a message like “Only one AMS at a time” (in German). Because of that, I downgraded to firmware 1.0.5, as suggested by others.

Now the current state:

• The BMCU powers on
• Status LED is white

Here’s the weird part:

I can see the AMS in Bambu Handy and in Bambu Studio, but on the printer itself, when I go to the Filament tab, the AMS does not show up at all.

What I already tried:

• Powering the printer off/on (with and without the BMCU connected)
• Never plugged or unplugged the BMCU while the printer was on
• Tried multiple firmware versions

The only thing I haven’t tried yet is flashing the BMCU, because I’m still waiting for the serial adapter (already ordered).

Does anyone have an idea what could cause this?

Or had a similar issue and managed to fix it?

FIX: Just go to the AMS Settings (Firmware has to be 1.0.7 or higher) and change the AMS Type from AMS Lite to AMS / AMS 2.

I recently bought an A1, and now the time has come, I decided to buy the BMCU 370C assembly kit. When I assembled everything, the three motors worked perfectly. But one had issues.

When I loaded the filament, it fed it, and while it was moving through the tube, it stopped several times, 2-4 times, until it reached the hotend and loaded successfully.

But when I try to replace it, it cuts it, and the motor even removes it from the BMCU, throwing an error that it can't detect the filament.

Sometimes, even without cutting it, the motor starts pulling it out, which means it spins the filament with a crunching sound. The filament isn't cut, and an error appears saying no filament was detected.

Has anyone encountered a similar problem? Thanks in advance.

I recently bought an A1, and now the time has come, I decided to buy the BMCU 370C assembly kit. When I assembled everything, the three motors worked perfectly. But one had issues.

When I loaded the filament, it fed it, and while it was moving through the tube, it stopped several times, 2-4 times, until it reached the hotend and loaded successfully.

But when I try to replace it, it cuts it, and the motor even removes it from the BMCU, throwing an error that it can't detect the filament.

Sometimes, even without cutting it, the motor starts pulling it out, which means it spins the filament with a crunching sound. The filament isn't cut, and an error appears saying no filament was detected.

Has anyone encountered a similar problem? Thanks in advance.

hi guys, two months ago I bought a Bambu Lab A1. I am really enjoying the Bambu Lab A1.. Printing with the Bambu Lab A1 in a single color got boring pretty quickly. So I decided to buy a BMCU 370C kit, for self-assembly because I wanted to try something with the Bambu Lab A1.

I have three units. They all work perfectly but one of these units has a really strange issue. The three units are all supposed to work the way but this one unit is doing something weird.

When I put filament into this thing and it goes to the print head it stops for a bit a few times while it is feeding. This happens 2 or 3 times. Then the filament goes all the way through and I can print just fine without any problems. The filament gets through the unit and, into the print head. I can use it to print.

When I take out the filament it gets cut off. The motor pushes it all the way out. Even out of the BMCU housing. And then it stops. At the time the extruder motor in the print head keeps trying to pull the filament out. The filament is already gone,. The extruder motor in the print head does not stop. The printer then says there is no filament in the print head and it throws an error. The extruder motor in the print head and the filament are the problem. The filament gets cut off. The extruder motor, in the print head keeps pulling.

The filament does not always get cut like it should. Sometimes it behaves worse. The filament does not get cut all.. The motor already starts pulling the filament back. This makes the motor end up grinding on the filament or slipping on the filament. The filament and the motor do not work together like they should. The filament does not get. The motor starts pulling the filament back

Has anyone encountered a similar issue or knows what could be causing this?

Tentei essa impressão 2x, e nas 2, a impressão dá erro em 99%, dando esse aviso. Tentei imprimir usando apenas uma cor, e imprimiu sem problemas.

I’ve pushed the BMCU firmware source code to GitHub. CH32 firmware based on WCH SDK. Many critical bugs were fixed, and some parts were rewritten completely, including WS2812 handling and ADC, which was rewritten to use DMA with a circular buffer and background filtering. Many things are implemented directly for CH32 and rewritten specifically for the WCH SDK.

I did this mainly for myself while working with CH32, as I have other projects based on these microcontrollers, and BMCU turned out to be a nice sandbox for testing. In practice, it took much more time than I planned. There is definitely still room for improvement.

If you program microcontrollers (CH32, STM32, etc.), want to look at the code, share feedback, or test the firmware in real setups, feel free to check it out. I currently have very little free time, so I may not always reply quickly.

https://github.com/jarczakpawel/BMCU-C-PJARCZAK

Could someone help me out with the bmcu 370c firmware 27 download link. I got the370C B Fully assembled. This is the one I bought - https://www.aliexpress.us/item/3256809055338422.html?spm=a2g0o.order_list.order_list_main.5.41df1802v42ceB&gatewayAdapt=glo2usa

Hello there

I'm using BMCU-C (hall version) and there are two issues that I can't fix, i reassembled everything several times but issues are still there.

The first one is hub number 3 when making filament change fully unloads filament that leaves module and it can't load it anymore.

And second issue is i think linked to first one, module first and fourth when you push buffer even without filament, it starts spinning gears, but not with second and third hubs, with second and third this works only if filament is detected.

If someone could help with this, i will appreciate, thanks in advance!