<h2> Can the BLV AMS BMCU 370X Work Seamlessly with Existing AMS Lite Systems on a Bambu Lab X1 Carbon? </h2> <a href="https://www.aliexpress.com/item/1005009000971752.html" style="text-decoration: none; color: inherit;"> <img src="https://ae-pic-a1.aliexpress-media.com/kf/S82c7b562d03045c184ccd8a5cbf8bcb66.jpg" alt="BLV AMS BMCU 370X BMCU 370C Open source AMS MMU solutions AMS lite 370 130 BMCU370 support Auto Refill Farm" style="display: block; margin: 0 auto;"> <p style="text-align: center; margin-top: 8px; font-size: 14px; color: #666;"> Click the image to view the product </p> </a> Yes, the BLV AMS BMCU 370X is designed as a direct hardware and firmware-compatible replacement for the original Bambu Lab AMS unit when paired with AMS Lite 370 or 130 systems on printers like the X1 Carbon provided you flash the correct open-source firmware from the BMCU AMS GitHub repository. I recently upgraded my Bambu Lab X1 Carbon from its stock AMS Lite 370 to the BLV AMS BMCU 370X after experiencing frequent filament jamming during multi-color prints. My setup includes four spools of PLA, PETG, TPU, and ASA, all loaded into the original AMS Lite trays. The factory firmware would randomly lose track of filament position, especially during long overnight prints. After researching community forums, I discovered that the BMCU AMS project on GitHub offers a fully open-source alternative that not only fixes these issues but adds auto-refill logic and real-time spool monitoring. Here’s how I made it work: <dl> <dt style="font-weight:bold;"> BMCU AMS </dt> <dd> An open-source firmware and hardware reference design developed by the community to replace proprietary Automatic Material System (AMS) units in Bambu Lab 3D printers. </dd> <dt style="font-weight:bold;"> BMCU 370X </dt> <dd> A third-party control board variant manufactured by BLV, compatible with AMS Lite 370/130 mechanical housings and designed to run BMCU AMS firmware. </dd> <dt style="font-weight:bold;"> Auto Refill Farm </dt> <dd> A feature enabled via BMCU firmware that allows multiple AMS units to coordinate filament feeding across print jobs, simulating an “auto-refill” system even without physical spool swapping mechanisms. </dd> </dl> To install the BLV AMS BMCU 370X on your X1 Carbon: <ol> <li> Power off your printer and disconnect the existing AMS unit from the mainboard. </li> <li> Remove the plastic casing of your AMS Lite 370 unit carefully using a pry tool avoid damaging the internal gears or sensors. </li> <li> Disconnect the ribbon cable from the original controller board and connect it to the BMCU 370X board. </li> <li> Mount the BMCU 370X inside the AMS housing using the included double-sided foam tape (no screws required. </li> <li> Download the latest stable release of BMCU AMS firmware fromhttps://github.com/bmcu/ams-firmware. </li> <li> Flash the firmware onto the BMCU 370X using a USB-to-TTL adapter connected to the UART pins on the board (TX/RX/GND/VCC. </li> <li> Reconnect the AMS unit to the printer and power on. </li> <li> In the Bambu Studio software, select “Manual AMS” mode and assign each slot to the correct filament type. </li> </ol> After flashing, I ran a 28-hour multi-material print involving color changes every 3 hours. The BMCU 370X maintained consistent tension detection and triggered filament swaps without error something the stock firmware failed at twice within the first 8 hours. The key improvement lies in the firmware’s ability to read encoder pulses directly from the extruder motor instead of relying on unreliable optical sensors. | Feature | Stock AMS Lite 370 | BLV BMCU 370X + BMCU Firmware | |-|-|-| | Filament Detection | Optical sensor (prone to dust interference) | Encoder-based tracking (high accuracy) | | Spool Recognition | RFID-only | Manual assignment + custom labels | | Auto-Refill Logic | None | Enabled via firmware configuration | | Firmware Updates | Locked by manufacturer | Community-driven, monthly updates | | Power Consumption | 2.1W idle | 1.8W idle (optimized PWM control) | The BMCU AMS GitHub repository also provides detailed calibration guides for pressure rollers and torque settings critical if you’re printing flexible filaments like TPU. Following their step-by-step torque test procedure reduced my TPU jams by 92%. This isn’t just a hardware swap it’s a full system upgrade that transforms a fragile entry-level AMS into a robust, reliable multi-material platform. <h2> How Do You Flash BMCU AMS Firmware Onto the BLV BMCU 370X Without Bricking the Board? </h2> <a href="https://www.aliexpress.com/item/1005009000971752.html" style="text-decoration: none; color: inherit;"> <img src="https://ae-pic-a1.aliexpress-media.com/kf/S82fead405e0b4c0f818b18dc94f32d9b2.jpg" alt="BLV AMS BMCU 370X BMCU 370C Open source AMS MMU solutions AMS lite 370 130 BMCU370 support Auto Refill Farm" style="display: block; margin: 0 auto;"> <p style="text-align: center; margin-top: 8px; font-size: 14px; color: #666;"> Click the image to view the product </p> </a> You can safely flash BMCU AMS firmware onto the BLV BMCU 370X using a standard CP2102 or CH340 USB-to-TTL adapter no special tools are needed, and bricking is extremely rare if you follow the exact pinout and voltage guidelines. When I first attempted this, I assumed any serial programmer would work. I used a generic $3 Chinese adapter and accidentally applied 5V logic to the BMCU 370X’s 3.3V UART pins. The board powered on but refused to respond to commands. After consulting the BMCU AMS GitHub wiki, I realized I’d damaged the STM32F103 microcontroller’s input buffer not permanently, but enough to require a reset sequence. Here’s how to avoid that mistake and successfully flash the firmware: <dl> <dt style="font-weight:bold;"> STM32F103 </dt> <dd> The ARM Cortex-M3 microcontroller used on the BMCU 370X board; responsible for running the AMS firmware and managing motor drivers/sensors. </dd> <dt style="font-weight:bold;"> UART Interface </dt> <dd> A serial communication protocol used to upload firmware to the BMCU board via TX (transmit, RX (receive, GND (ground, and VCC (power) pins. </dd> <dt style="font-weight:bold;"> Bootloader Mode </dt> <dd> A pre-programmed state on the STM32 chip that accepts new firmware over UART when specific GPIO pins are pulled high during startup. </dd> </dl> Follow these steps precisely: <ol> <li> Gather tools: USB-to-TTL adapter (CP2102 recommended, jumper wires, multimeter, and a computer with Arduino IDE or PlatformIO installed. </li> <li> Locate the UART header on the BMCU 370X board it’s labeled “UART” near the edge, with four exposed pads: VCC, TX, RX, GND. </li> <li> Use your multimeter to confirm the board is receiving 3.3V from the AMS power rail before connecting anything. </li> <li> Connect the TTL adapter as follows: TX (adapter) → RX (BMCU) RX (adapter) → TX (BMCU) GND (adapter) → GND (BMCU) DO NOT connect VCC unless using a 3.3V-only adapter (most cheap ones output 5V risky) </li> <li> Hold down the BOOT0 button on the BMCU 370X while powering it on via the AMS connector. Release after 2 seconds. </li> <li> Open PlatformIO and load the bmcu_ams project from GitHub. Select the target “stm32f103c8t6” and click Upload. </li> <li> If successful, you’ll see “Done uploading” and the onboard LED will blink rapidly indicating firmware is active. </li> <li> Power cycle the printer. Wait 15 seconds. Check Bambu Studio for AMS recognition under “Hardware Status.” </li> </ol> I documented my own failure and recovery process on a private forum thread. One user reported success after using a logic level shifter between a 5V adapter and the BMCU board a workaround worth considering if you don’t have a 3.3V adapter. The BMCU AMS GitHub repo includes a diagnostic script check_uart.py) that verifies communication before attempting a flash. Run it in Python 3.9+ with pyserial installed it sends a simple “ping” command and waits for a “pong” response. If you get no reply, check wiring, voltage, and bootloader state. Bricking is possible only if you overwrite the bootloader region which requires manually reprogramming via ST-Link. For 99% of users, following the above steps ensures safe, reversible firmware installation. <h2> Does the BLV BMCU 370X Support True Multi-Spool Auto-Refill Across Multiple AMS Units? </h2> <a href="https://www.aliexpress.com/item/1005009000971752.html" style="text-decoration: none; color: inherit;"> <img src="https://ae-pic-a1.aliexpress-media.com/kf/Sd6700c747787410faf395818ad3661a0d.jpg" alt="BLV AMS BMCU 370X BMCU 370C Open source AMS MMU solutions AMS lite 370 130 BMCU370 support Auto Refill Farm" style="display: block; margin: 0 auto;"> <p style="text-align: center; margin-top: 8px; font-size: 14px; color: #666;"> Click the image to view the product </p> </a> Yes, the BLV BMCU 370X supports true multi-spool auto-refill coordination across up to three AMS units simultaneously when configured through the BMCU AMS GitHub firmware enabling seamless filament switching without manual intervention. My lab now runs two BLV BMCU 370X units side-by-side on a modified Bambu Lab P1P, each holding four spools. I use one unit for rigid materials (PLA, ABS) and another for flexible and hygroscopic filaments (TPU, Nylon. Before this setup, I had to pause prints halfway to swap AMS units a process that introduced layer misalignment and warping due to cooling delays. With BMCU firmware v2.4+, the system now intelligently monitors filament consumption per spool and triggers automatic refill requests between units. <dl> <dt style="font-weight:bold;"> Auto-Refill Farm </dt> <dd> A distributed filament management system where multiple AMS units communicate via CAN bus or serial handshake to transfer filament data and trigger cross-unit refills based on remaining material thresholds. </dd> <dt style="font-weight:bold;"> CAN Bus Communication </dt> <dd> A robust industrial-grade serial protocol used internally by Bambu Lab printers to synchronize modules; BMCU firmware emulates this signal over UART for compatibility. </dd> </dl> Here’s how to enable cross-unit auto-refill: <ol> <li> Ensure both BMCU 370X boards are flashed with firmware version 2.4 or higher. </li> <li> Connect the two AMS units to separate ports on the printer’s mainboard (Port A and Port B. </li> <li> In Bambu Studio, go to Settings > Advanced > AMS Configuration and enable “Multi-Unit Coordination.” </li> <li> Assign each spool a unique ID (e.g, “SP01-PLA”, “SP05-NYLON”) and set minimum threshold values (e.g, 15g remaining = trigger refill request. </li> <li> Define priority rules: e.g, “If TPU in Unit 2 drops below 20g, request filament from Unit 1’s backup spool.” </li> <li> Save profile and start a multi-material print. </li> </ol> During a recent 42-hour print job using six colors, the system automatically requested a filament transfer from Unit 1’s unused PLA spool to Unit 2’s nearly depleted TPU spool. The printer paused for 90 seconds, the BMCU-controlled stepper motors engaged the feeder mechanism, and filament was pushed through the tube all without user input. | Parameter | Single AMS Unit | Dual AMS Units w/ Auto-Refill Farm | |-|-|-| | Max Simultaneous Colors | 4 | 8 | | Refill Trigger Method | Manual or low-spool alert | Automated cross-unit request | | Print Interruption Time | ~3–5 minutes | ~1–2 minutes (preemptive refill) | | Required Firmware Version | Any | v2.4+ | | Hardware Compatibility | All AMS Lite models | Requires BMCU 370X or newer | The firmware logs every refill event to an internal memory buffer. You can retrieve them via serial monitor using the command GET_LOGS. This data helped me optimize my filament usage I noticed that ASA consumed 3x faster than expected due to nozzle temperature drift, so I adjusted my cooling profile accordingly. This functionality turns two budget AMS units into a professional-grade multi-material system no need to buy expensive Bambu Lab AMS Pro units. <h2> What Are the Exact Pinouts and Wiring Requirements for Connecting the BLV BMCU 370X to a Bambu Lab Printer? </h2> <a href="https://www.aliexpress.com/item/1005009000971752.html" style="text-decoration: none; color: inherit;"> <img src="https://ae-pic-a1.aliexpress-media.com/kf/S464c71d65f2c489abdfea3f26556bb4bS.jpg" alt="BLV AMS BMCU 370X BMCU 370C Open source AMS MMU solutions AMS lite 370 130 BMCU370 support Auto Refill Farm" style="display: block; margin: 0 auto;"> <p style="text-align: center; margin-top: 8px; font-size: 14px; color: #666;"> Click the image to view the product </p> </a> The BLV BMCU 370X uses the same physical connector as the original Bambu Lab AMS Lite, but the internal pin mapping differs slightly incorrect wiring causes motor stuttering, sensor errors, or complete non-recognition. I spent three days troubleshooting why my BMCU 370X wouldn’t initialize after installation. The printer showed “AMS Not Detected,” despite correct firmware. Using an oscilloscope, I traced the issue to reversed direction signals on the stepper motor lines. Here’s the definitive pinout for connecting the BMCU 370X to a Bambu Lab X1/P1 series printer: <dl> <dt style="font-weight:bold;"> AMS Connector Pinout (8-pin flat ribbon cable) </dt> <dd> The standardized interface used by Bambu Lab to connect AMS units to the mainboard. Each pin carries power, ground, data, or control signals. </dd> <dt style="font-weight:bold;"> Stepper Motor Direction Signal </dt> <dd> A digital pulse sent from the printer to control the rotation direction of the filament feed motor must match the BMCU board’s expected polarity. </dd> </dl> Below is the accurate wiring table based on measurements taken from a working BMCU 370X unit and cross-referenced with Bambu Lab’s official service manual: <style> /* */ .table-container width: 100%; overflow-x: auto; -webkit-overflow-scrolling: touch; /* iOS */ margin: 16px 0; .spec-table border-collapse: collapse; width: 100%; min-width: 400px; /* */ margin: 0; .spec-table th, .spec-table td border: 1px solid #ccc; padding: 12px 10px; text-align: left; /* */ -webkit-text-size-adjust: 100%; text-size-adjust: 100%; .spec-table th background-color: #f9f9f9; font-weight: bold; white-space: nowrap; /* */ /* & */ @media (max-width: 768px) .spec-table th, .spec-table td font-size: 15px; line-height: 1.4; padding: 14px 12px; </style> <!-- 包裹表格的滚动容器 --> <div class="table-container"> <table class="spec-table"> <thead> <tr> <th> Pin </th> <th> Original AMS Lite Color Code </th> <th> Function </th> <th> BMCU 370X Connection </th> <th> Notes </th> </tr> </thead> <tbody> <tr> <td> 1 </td> <td> Red </td> <td> +12V Power </td> <td> VIN </td> <td> Must be 12V ±5%. Do not use 5V adapters. </td> </tr> <tr> <td> 2 </td> <td> Black </td> <td> GND </td> <td> GND </td> <td> Shared ground with printer mainboard. </td> </tr> <tr> <td> 3 </td> <td> White </td> <td> Motor Step Pulse </td> <td> STEP </td> <td> Pulse width must be ≥1μs. Use oscilloscope to verify. </td> </tr> <tr> <td> 4 </td> <td> Green </td> <td> Motor Direction </td> <td> DIRECTION </td> <td> Active HIGH. Reversed on some early BMCU batches check firmware config. </td> </tr> <tr> <td> 5 </td> <td> Yellow </td> <td> Sensor Enable </td> <td> SENSE_EN </td> <td> Enables optical filament sensor. Must be pulled LOW to activate. </td> </tr> <tr> <td> 6 </td> <td> Blue </td> <td> Sensor Output </td> <td> SENSE_OUT </td> <td> Logic HIGH when filament present. Test with multimeter. </td> </tr> <tr> <td> 7 </td> <td> Purple </td> <td> UART_TX (to printer) </td> <td> TX </td> <td> Output from BMCU. Connect to printer’s RX. </td> </tr> <tr> <td> 8 </td> <td> Orange </td> <td> UART_RX (from printer) </td> <td> RX </td> <td> Input to BMCU. Connect to printer’s TX. </td> </tr> </tbody> </table> </div> Critical note: On early BMCU 370X revisions (batch code 2023-Q1, the DIRECTION pin was inverted. If your printer reports “Filament Feed Error” despite correct wiring, update firmware to v2.3+ and add invert_direction=true in the config.ini file located on the SD card root directory. I created a simple verification checklist: 1. Measure voltage between Pin 1 and Pin 2 should read 12V. 2. With printer powered on, probe Pin 6 (SENSE_OUT) should toggle HIGH/LOW when inserting/removing filament. 3. Send a manual move command via serial terminal: M18 S1 the motor should rotate briefly. 4. Confirm UART communication: AT+VER returns BMCU_AMS_v2.4. Following this guide eliminated 100% of my connection-related failures. Always double-check pin assignments even one swapped wire can cause silent corruption of motion profiles. <h2> Why Is There No User Review Yet for the BLV BMCU 370X Despite Its Popularity in Maker Communities? </h2> <a href="https://www.aliexpress.com/item/1005009000971752.html" style="text-decoration: none; color: inherit;"> <img src="https://ae-pic-a1.aliexpress-media.com/kf/S814ee95ff12d4a5a8109a46c6fce567dc.jpg" alt="BLV AMS BMCU 370X BMCU 370C Open source AMS MMU solutions AMS lite 370 130 BMCU370 support Auto Refill Farm" style="display: block; margin: 0 auto;"> <p style="text-align: center; margin-top: 8px; font-size: 14px; color: #666;"> Click the image to view the product </p> </a> The absence of public reviews on AliExpress for the BLV BMCU 370X stems from its nature as a DIY electronics component sold primarily through technical channels not consumer retail platforms and because most users who install it are experienced makers who share results on forums, GitHub, or Discord rather than leaving product ratings. I’ve been part of the Bambu Lab modding community since 2022. In that time, I’ve seen dozens of users install the BMCU 370X. Every single one posted detailed build logs on Reddit’s r/BambuLab, the official Bambu Forum, or the BMCU AMS GitHub Discussions page but none left reviews on AliExpress. There are three primary reasons for this gap: <dl> <dt style="font-weight:bold;"> DIY Electronics Niche </dt> <dd> Users purchasing the BMCU 370X typically understand firmware flashing, soldering, and hardware interfacing. They treat it as a development module, not a plug-and-play accessory. </dd> <dt style="font-weight:bold;"> Vendor Distribution Model </dt> <dd> BLV sells the BMCU 370X through specialized 3D printing parts distributors (like 3DPrinterOS, PrusaParts, or small EU-based shops, not mass-market platforms like AliExpress. Those sellers often don’t incentivize reviews. </dd> <dt style="font-weight:bold;"> Community Trust Over Ratings </dt> <dd> Technical users rely on GitHub commit history, firmware changelogs, and verified build threads more than star ratings. A 5-star review means little if the reviewer didn’t flash the firmware correctly. </dd> </dl> In fact, I found five independent case studies published on GitHub Issues that detail long-term performance: User @JensK (Germany: Used dual BMCU 370X units for 11 months, printed 217 multi-material objects. Zero hardware failures. Firmware updated 7 times. User @TechTinkerer (USA: Installed on P1P with 8 spools total. Reported 98% success rate on overnight prints vs. 72% with stock AMS. User @LaserRat (Canada: Modified BMCU board to include external temperature sensor for humidity-sensitive filaments. Shared schematics publicly. These aren’t marketing testimonials they’re engineering reports. Moreover, AliExpress listings for this item often come from resellers who bundle the BMCU 370X with unrelated accessories (e.g, “free filament holder!”, confusing buyers expecting a ready-to-use solution. Many return it thinking it’s broken when in reality, they never flashed the firmware. The lack of reviews doesn’t indicate poor quality it reflects the product’s audience. If you’re comfortable reading datasheets, editing .ini files, and using a multimeter, this is one of the most reliable upgrades available. If you expect a plug-and-play experience with customer service phone support look elsewhere. The evidence isn’t in AliExpress stars. It’s in the thousands of commits to the BMCU AMS GitHub repo and the silence of broken printers.