3DSteel V2 - 24V 32 bits 3D Printer - Evolution of P3Steel / Prusa i3 Steel

The HTA3D 3DSteel V2 is a Cartesian 3D printer with a steel frame, 24 V electrical system and 32-bit control. Designed by HTA3D as an evolution of our P3Steel and 3DSteel machines, it retains an open, repairable and understandable architecture while adding more modern electronics, quiet drivers, a dual-drive direct extruder, filament sensor and 3DTouch probing.

It is available as a partially preassembled DIY kit or with an assembly and calibration service. Its nominal 220 x 220 x 210 mm build volume covers most domestic, educational and functional parts, while the selector lets you choose the frame, linear motion, hotend, heated bed and build surface.

Main features

Power ratings and dimensions are nominal. The usable area may be affected by the configured origin, installed surface, firmware and assembly tolerances. Safe operating temperature depends on the complete hotend, sensor, firmware, bed, build surface and material, so one universal limit is not stated for every configuration.

What it adds over a P3Steel

• 24 V system: requires less current for the same power than a 12 V system, helping to reduce losses in correctly sized wiring and connections.
• 32-bit mainboard: the SKR V1.4 provides more processing capacity and a more modern integration than the Mega/RAMPS combination used by earlier generations.
• TMC2209 in UART: current and operating modes can be configured in firmware, and sensorless homing can be used on X/Y.
• HTA3D V2 extruder: dual drive, short filament path, adjustable tension, filament sensor, 3DTouch and integrated cooling.
• Dual Z with integrated lead screws: two motors with 310 mm T8x8 lead screws and POM nuts, without separate motor couplers.
• Magnetic bed: the flexible sheet can be removed to make part release easier.

The HTA3D P3Steel remains a more traditional and economical learning platform. The 3DSteel V2 is intended for users who want to retain that open philosophy with a more current electrical and electronic platform.

Available options

The options form part of the machine configuration. Choose them for the intended application rather than treating every option as a universal upgrade.

The bed with embedded magnets is also available as a catalogue replacement part. Always use a compatible ferromagnetic flexible sheet and recheck first-layer height after changing the bed or sheet.

Mechanics and motion

The tab-and-bolt frame forms the machine's structural reference. X/Y transmission uses 6 mm GT2 belt, two 20-tooth drive pulleys and tensioners built into the design. Six 8 mm smooth rods guide motion: two 375 mm rods on X, two 350 mm rods on Y and two 320 mm rods on Z.

The Z axis uses two motors with integrated 310 mm T8x8 lead screws and POM nuts. Both motors share the mainboard's Z channel and must remain mechanically synchronised. After transport, work on the X axis or any visible height difference between sides, check this synchronisation before recalibrating the bed.

Mechanical printed parts are made in PETG. The documented enclosures have historically been produced in PLA 3D850. Colour and some manufacturing details may vary without changing the function of the assembly.

HTA3D V2 direct extruder

The direct extruder places its motor and drive mechanism on the X carriage. Two gears guide the filament from both sides and the tensioner allows pressure adjustment. The short path simplifies retraction control and can work well with flexible filaments when hardness, speed, temperature and guidance are suitable.

The toolhead integrates a 3010 heatsink fan, 4020 part-cooling fan, mechanical filament-presence sensor and 3DTouch. The HTA3D V2 extruder is available as a specific replacement. Before replacing the hotend, sensor or carriage parts, identify the installed variant and repeat the affected calibrations.

The V6 configuration includes a bimetal heatbreak, brass block, 24 V/50 W cartridge and 100K Beta 3950 NTC thermistor. The Dragon option is the SF model and uses the same heater and sensor in this machine. Operating temperature is not determined by block material alone: it is also limited by the sensor, heater, firmware, nozzle, cooling and material.

24 V, 32-bit electronics

The standard SKR V1.4 uses an LPC1768 microcontroller and four UART-controlled TMC2209 drivers. X and Y use sensorless homing; Z is referenced by the 3DTouch. Both Z motors connect to the same motion channel and are not independent Z axes.

The TMC2209 allows current, StealthChop/SpreadCycle operation and sensitivity to be configured in firmware. These values depend on motors, load, speed and assembly, so they should not be copied from another printer without checking temperature, motion and repeatability. Related replacements include the SKR V1.4, TMC2209 driver and 3DTouch. Revision, orientation, jumpers, pinout, wiring and configuration must be verified for every replacement.

The 24 V, 360 W power supply includes cooling, a terminal cover, switch and detachable mains cable. Protective earth, correct input-voltage selection where a selector is fitted, terminal tightness and strain relief are essential checks. Installation and inspection of mains-connected wiring should be carried out by a suitably skilled person.

Kit contents

Exact contents depend on the selected options and may evolve with production revisions. The documented package is organised into the following modules:

For maintenance or rebuilding, we also supply the 3DSteel V2 printed-parts set, Y-axis printed parts, SKR V1.4 electronics enclosure and 3DSteel V2 fastener kit.

What arrives preassembled

• Complete extruder with prepared connections.
• Soldered and insulated heated bed with prepared wiring.
• Prepared power supply with cover, switch and detachable connection.
• Printed X-axis subassemblies with bearings and fasteners installed.
• LCD fitted in its enclosure and ready to attach to the frame.

The user completes the frame, axes, transmission, wiring between modules and commissioning by following the tutorials. Time depends on experience, tools and the care devoted to checks. Although the main subassemblies do not need to be manufactured or soldered, this remains a mechanical and electrical project that should be assembled methodically.

Assembly and first commissioning

1. Assemble the frame without forcing tabs and check squareness before final tightening.
2. Verify that every axis moves freely before installing or tensioning belts.
3. Keep both Z lead screws synchronised and the X axis parallel to its mechanical reference.
4. Check polarity, protective earth, input voltage, terminals, connectors and strain relief before applying power.
5. At room temperature, verify that hotend and bed readings are plausible.
6. Test fans, heaters and movements one at a time from a safe position.
7. Trigger the 3DTouch manually to confirm stopping behaviour before the first Z home.
8. Tune X/Y sensorless sensitivity on the actual machine; a copied value may cause frame impacts or premature triggering.
9. Calibrate Z offset, first layer, extrusion and thermal control before long prints.

Marlin setup and calibration

The machine is supplied and documented with Marlin. The firmware provided for the selected combination should be the starting point; do not replace a working configuration with generic values.

• Board: standard SKR V1.4 with LPC1768 environment and the corresponding BOARD_BTT_SKR_V1_4 definition.
• Drivers: UART TMC2209 for X, Y, Z and E. Both Z motors share one driver.
• Geometry: nominal 220 x 220 x 210 mm area, checked against the real origin, margins and probe position.
• Sensorless: X/Y only. Sensitivity is adjusted for each unit through the appropriate Marlin function or menu where available.
• Z: homing by 3DTouch. Direction, deployment and trigger behaviour must be checked before the first home.
• Temperature sensors: 100K Beta 3950 NTC on hotend and bed. When compiling Marlin these normally correspond to option 11 (TEMP_SENSOR_0 11 and TEMP_SENSOR_BED 11); retain the supplied configuration and validate a plausible room-temperature reading before heating.

The historical mechanical values of 80 steps/mm for X/Y and 400 steps/mm for Z are consistent with 20-tooth GT2 transmission and T8x8 lead screws at the documented microstepping, but they do not replace the supplied configuration. Calibrate the extruder from its starting value by taking a real measurement.

After changing the hotend, block, heater, sensor or bed, perform the appropriate thermal autotune with M303 and save it with M500 when EEPROM is enabled. Current Marlin Linear Advance uses M900 K...; its K factor depends on filament, temperature, nozzle, speed and Marlin version.

Advanced conversion to Klipper

Klipper is not part of the supplied configuration, but the SKR V1.4 can run it. Conversion requires compiling and installing LPC1768 firmware, adding a host computer and rebuilding the full pin, safety and calibration configuration. Klipper's official generic SKR V1.4 configuration is a board reference, not a ready-to-use printer file.

• X/Y may start from rotation_distance: 40 only with the confirmed 20-tooth GT2 transmission.
• Z may start from rotation_distance: 8 only for the installed T8x8 lead screws.
• The extruder's rotation_distance must be calibrated rather than copied from another unit.
• Sensorless operation requires TMC2209 setup, DIAG/virtual-endstop pin, homing current, sensitivity and a sequence that moves away from the stop after homing.
• The 3DTouch requires correct pins, a safe trigger test, PROBE_CALIBRATE and a new mesh whenever geometry changes.
• Hotend and bed should be tuned with PID_CALIBRATE; save the results afterwards with SAVE_CONFIG.

A RepRapFirmware guide is intentionally omitted because it is not a natural integration for the current SKR V1.4/3DSteel V2 combination and would require assumptions that depend on specific hardware and firmware.

Printing materials

• PLA and PETG: natural general-purpose choices when temperature, cooling and surface are adapted to the brand.
• TPU and TPE: the direct extruder and short path help, but hardness, flow and retraction remain important.
• ABS and ASA: can be printed with suitable configuration and ventilation. As an open printer, large parts may require an enclosure and controlled surroundings.
• Nylon, PC and technical materials: depend on hotend variant, nozzle, drying, bed, surface and environment. Check them individually.
• Abrasive filament: requires a wear-resistant nozzle; a conventional brass nozzle will wear with fibres and mineral fillers.

This is not presented as a platform for PEEK, PEI or other extreme-temperature industrial polymers. Matching filament diameter or nominal temperature does not guarantee process compatibility.

Maintenance and spares

• Keep rods clean and use maintenance appropriate to LM8UU or DryLin; DryLin bushings operate dry.
• Check belt tension and alignment without overtensioning bearings or axes.
• Periodically inspect Z synchronisation, drive gears, fans, connectors and terminals.
• Clean the build surface according to its material and avoid touching the print area.
• After changing a nozzle, hotend, bed, probe or build sheet, recheck Z offset, first layer and affected thermal or extrusion calibrations.

Assembly documentation

HTA3D maintains illustrated tutorials covering the frame and Y axis, X/Z axes and extruder, heated bed and electronics, commissioning and separate extruder assembly:

• Tutorial 1: frame and Y axis.
• Tutorial 2: X and Z axes and extruder.
• Tutorial 3: bed, power supply and electronics.
• Tutorial 4: commissioning.
• HTA3D V2 extruder assembly.

Tutorials may show previous revisions or options. For a new machine, its selector, received wiring and supplied firmware take precedence.

It is for you if

• You want an open printer that you can understand, maintain and repair.
• You value a steel frame and widely documented components.
• You want to learn assembly and calibration without preparing every subassembly from scratch.
• You prefer direct extrusion for compatible standard and flexible materials.
• You want to choose between a DIY kit and an assembled, calibrated machine.

It is not for you if

• You want a fully automatic enclosed printer that can be used without understanding its maintenance.
• You require integrated networking, camera, resonance compensation or other current-platform features as standard.
• Maximum speed is your overriding priority; its moving bed and direct toolhead favour robustness, control and repairability.
• You regularly need technical materials that require a heated chamber or extreme temperatures.

The 3DSteel V2 is intended for users who want a functional, configurable 3D printer and a machine they can continue to understand and maintain over time.