Huvud is a compact 3D-printer toolhead controller designed for direct-drive setups and Klipper. Its 42×42 mm footprint is described by the project as the world’s smallest, but that superlative is the project’s claim, not an independently verified comparison. Huvud combines an extruder stepper driver, heater and fan outputs, sensor inputs, and CAN connectivity on a board mounted near the toolhead.
What Huvud is—and what “world’s smallest” means
Huvud is a small, open-source controller board that moves several printer-control functions from the main electronics enclosure to the direct-drive toolhead. The project describes the board as 42×42 mm and calls it a very small 3D-printer board for a direct-drive toolhead. The “world’s smallest” label should be read as the project’s characterization: the available material does not establish a measured ranking against every other toolboard.
The board design is made in KiCad and is intended for Klipper. Its focused feature set is useful when the goal is to reduce wiring between a printer’s main controller and moving toolhead, rather than to replace the printer’s main controller altogether.
What the Huvud board controls
Huvud brings the following connections and functions to the toolhead:
The Tool Desk
Outbyte Driver Updater FREEFix the driver behind crashes, sound loss and screen glitchesFind Drivers →Outbyte PC Repair FREERepair Windows errors before they cause bigger problemsFix Now →#1 Best Overall
- H36 Combo V1.3 is a newly designed high-temperature tool board running Klipper-firmware. Based on STMG0B1T3, the maximum operating temperature can reach 125 degrees celsius (CAN only). It also provides two communication methods: CANBUS and USB. The onboard USBHUB has up to two USB interfaces (or one CAN and one USB), which can be used to connect to the IDM scanner leveling sensor-camera, etc.
- Accelerometer ADXL345: super heat resistance up to 85℃/ 185℉; Runs Klipper firmware, fit for most FDM printing projects. Note: please refer to the information on our wiki before placing an order. Search for the keyword H36 Combo on the wiki or contact us for more detailed information before making a purchase
- Application: print head with NEMA14/36mm round Motor.
- Firmware configuration and compilation, more information please reference to fysetc wiki or github
- Easy to install: physical connections please follow the left pictures.
- Extruder: one TMC2209 stepper driver for the extruder motor.
- Heater: a high-current MOSFET output for the hotend heater.
- Fans: two MOSFET fan outputs.
- Temperature: a thermistor input.
- Position or filament sensing: one input that can be used for an endstop or filament-runout sensor.
- Communications and firmware flashing: CAN bus and USB.
- Processing: an STM32F103 72 MHz 32-bit ARM microcontroller.
The project specifies 12–24 V main power and prefers 24 V because it reduces current for a given power load. Check the board documentation and your printer’s wiring before connecting power; voltage compatibility alone does not confirm that every heater, fan, motor, or connector is suitable for a particular installation. Huvud project repository.
How Huvud connects to a Klipper printer
CAN for the toolhead link
Huvud’s main architectural idea is to place a small controller near the extruder and connect it to the printer host over CAN. The project describes chaining small boards to a host with power and a twisted-pair CAN connection. That arrangement can simplify the moving toolhead cable bundle and can suit multiple-head or tool-changing setups. The host still needs a compatible CAN interface and a correctly configured Klipper installation.
Rank #2
- TH board set V9 for X1 series toolhead: This circuit board set is the TH board V9 for X1 series printers. Used for toolhead control and signal management.
- Circuit boards for X1 and X1C toolhead: Fits X1 and X1C printers as toolhead circuit boards. Manages electrical connections between the toolhead components and the main board.
- Replacement TH board set for X1 series: Used when the original toolhead circuit boards fail or require replacement. Direct replacement for the factory installed boards.
- For X1 series toolhead system: Works with the toolhead system on X1 series printers. Controls functions including heating, sensing, and motion.
- 3D printer accessory for toolhead repair: This circuit board set is a replacement accessory for the X1 series toolhead. Used for maintenance of the toolhead electrical system.
USB as an alternative
The board also has USB, which is included for firmware flashing and can be used as the connection method when preferred. USB availability does not remove the need to configure the host and Klipper for the chosen communication path; follow the project’s current instructions for firmware and pin configuration rather than assuming CAN and USB are interchangeable without setup.
Extruder current and cooling limits
The documented current figures come from Pontus Borg’s 2020–2021 project logs, not from a general rating for every motor or installation. In the reported setup, the board reached 1 A RMS with the board warm to the touch. At 1.2 A it became hot; above that, the author recommended small cooling fins and noted that results vary with the motor. The design goal was to operate without extra cooling, but the logs do not establish that as a guarantee for all motors, airflow, enclosures, or ambient temperatures. Pontus Borg’s Huvud project logs.
Rank #3
- Compatible Models: This toolhead board is compatible with Creality K2, K2 Pro, K2 Plus 3D printers.
- High Quality: 100% original Printhead board_CR1FN200338C16_32, reliable quality.
- Easy to Install: Simply remove the old PCBA board, replace it with the new PCBA board, and complete the wiring without additional firmware updates.
- Please disconnect the power before completing the installation to avoid damage to the tool head board caused by hot-plugging.
- Package: 1x CR1FN200338C16_32 toolhead board for K2 series 3D printers.
For a build, treat those figures as observations from the documented test setup, not as a universal safe-current specification. Motor selection, current configuration, driver cooling, board airflow, and surrounding temperatures all affect the result. If the driver runs hot, reduce the configured current or improve cooling rather than relying on the project’s design goal.
Where to find Huvud and what availability claims mean
The GitHub README names Lukes Lab and Tindie as purchase destinations. Hackaday records the project as created on August 22, 2020, and last updated roughly four years before the 2026 access date. A 2021 log says v0.5 was difficult to produce amid component shortages and that an improved v0.6 was in development; another 2020 log describes a planned first production batch of 200 boards. Those are historical notes, not evidence of present stock, current pricing, or a current production run.
Rank #4
- Only compatible with BambuLab V6 Version P1P/ P1S 3d printing project. Not for X1/X1-Carbon/X1C/X1E/A1/A1 Mini
- The extrusion connection board is an auxilary circuit board of thetool-head board, and it is used to expand the interface of functional components, such as the hotend and extruder unit.
- When to use: Loose terminals and plugs on the circuit board, or it was confirmed that the board was faulty, the board was burnt out or any connector or component on the pcb board was damaged
- Easy to install, only need to remove part of the print head enclosure, and remove the FPC cable, disconnect the 3 cable connectors (the hall switch cable filament sensor, hotend cooling fan cable, and the heater cable), that is can remove the interface board, can directly replace the original
- Learn more about the replacement of the Extruder Interface Board for P1 Series on Wikii
Check the named seller pages for live stock, price, shipping, and board revision, and confirm that the seller is authentic before ordering. The project’s purchase links are listed in the Huvud README.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Is Huvud the right toolboard for your printer?
Huvud is a fit to investigate if you need a very compact Klipper toolhead controller with an onboard extruder driver, heater and fan outputs, a thermistor connection, one endstop/runout input, and CAN or USB connectivity. Its small footprint and concentrated toolhead functions are the point; they also mean you should confirm that its I/O and thermal headroom match your particular build.
Best Value
- Perfect Compatibility & 5‑Second Quick Swap: Exclusively fits the No.1 print head position of Snapmaker U1, supports SnapSwap system for rapid hot‑swap within 5 seconds, greatly improving printing efficiency.
- Premium Stainless Steel Nozzle for Wide Filament Compatibility: Features a 0.4mm stainless steel nozzle with a maximum temperature of 300°C, compatible with PLA, ABS, PETG, TPU and more common 3D printing materials.
- Smart Sensor Design for Stable Printing: Built‑in embedded inductive sensors support automatic bed leveling and real‑time runout detection, avoiding printing errors and reducing filament waste.
- Efficient Heat Dissipation & High‑Quality Build: Integrated cooling fan quickly cools the hot end for steady temperature control; constructed from sturdy plastic and metal, lightweight at only 299g with reliable long‑term performance.
- Complete Replacement Part & Easy Installation: Comes with 1 full print head unit, direct plug‑and‑play replacement, no complicated modification required for quick setup and use.
- Check the footprint and mounting: allow for connectors, wiring clearance, and access—not just the 42×42 mm board outline.
- Check the communication plan: decide whether the printer will use CAN or USB and verify host-side interface and Klipper setup.
- Check the load and sensors: verify the heater, fans, thermistor, extruder motor, and endstop or runout sensor against the board documentation and your intended configuration.
- Check thermal margin: the project logs report a warm board at 1 A RMS and hot operation at 1.2 A in their setup, so do not assume those operating conditions transfer unchanged to your printer.
- Check revision and availability: historical development notes do not confirm which revision is currently sold or whether stock is available.
For a comparison with other toolboards, use the actual board footprint, supported firmware, CAN/USB options, driver current and cooling, heater and fan outputs, sensor count, voltage range, connector layout, documentation, and current availability. Huvud’s documented 42×42 mm size is notable, but size alone does not determine whether it is the better choice.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
