AXI ELF-850 is a conversion kit that turns the rear lift-arm system of classic hydraulically-controlled tractors into electronic control — the next generation of the ELF-812 series and now the standard model. Two HCT402 servo motors drive the position and precision arms independently, making the rear hydraulic arms 100% electric.
Control is done via a single joystick, without reaching for the levers beside the seat. The motors connect to the main unit via RS-485 with a direct plug connection; thanks to the locked, sealed socket design, the main unit, joystick or fender switches can be swapped in the field without rewiring.
› The precision arm is now electronic too. The ELF-812 was halfway there: depth was electronic, draft control stayed manual. On the ELF-850 the precision motor runs independently from the rest of the system — even at 100% precision, your Lift-O-Matic setting keeps working.
ELF-850 at a Glance
⚡ Actuator
2× HCT402 servo motor
⚙ Control Arms
Position + precision (both electronic)
⇄ Communication
RS-485, direct plug connection
◆ Full Stroke Time
Under 1 second
○ Calibration
Automatic, stored in memory
★ Warranty
3 Years + 10 Years Service
ELF-812 to ELF-850: Three Defining Changes
✓ The precision arm is now electronic
On the ELF-812 only the position arm was electronic; draft (precision) control stayed manual. On the ELF-850 the rear arms are genuinely 100% electric — since the two motors run independently, precision and Lift-O-Matic never lock each other out.
✓ Our own HCT402 servo motor
The imported linear motor is replaced by the AXI-made HCT402 servo, field-proven for 8 years — both much faster (full stroke under 1 second) and free of import supply dependency.
✓ Reversible installation
The arm is only disconnected from the gearbox; the original manual arms stay on the tractor. If there's a field failure or you change your mind, you can switch back to the original manual system any time.
Key Features
✓ Electronic Lift-O-Matic
Joystick right: lowers to the set working depth. Left: raises to the set lift limit. The ELF-850 adds this feature even if your tractor doesn't have it.
✓ Waterproof housing
Compact servo motor body sized to hide inside the gearbox; runs for years under pressure water, mud, oil and dust.
✓ Plug-in RS-485 connection
If the main unit, joystick or fender switches fail, they can be swapped in the field via the socket — no wire soldering needed.
✓ Automatic calibration
The working range is learned once during installation and stays in memory even after a power cut. If a motor runs in reverse, it can be corrected in the field via the switches.
✓ Safety-first fender switches
Used for hitching/unhitching implements; always run at low speed regardless of the speed setting.
✓ LED status indicator
Blinks while the motor is moving, stays solid when done; Lift-O-Matic and manual end points are shown in separate colours (purple / blue).
How Does It Work?
1
Mount it
Motors attach with brackets to the pin point where the arms connect to the gearbox; the original arms stay on the tractor.
2
Calibrate
Hold both fender switches together and power on; the motors learn the working range and return to normal position.
3
Work with the joystick
Forward/back for manual raise-lower; right/left for electronic Lift-O-Matic — automatically moves to the set depth or lift limit.
4
Lift at headlands with the switches
Fender switches are used for hitching/unhitching implements; always run slowly for safety.
Technical Specifications
| Motor type | HCT402 servo motor (2 units) |
| Communication | RS-485, direct plug connection to the main unit |
| Full stroke time | Under 1 second (~0.5s in practice) |
| Precision | Millimetre-scale at the lowest speed setting |
| Control inputs | Proportional joystick + fender switches |
| Unit settings | Lift limit, depth setting, calibration, speed setting |
| Extra setting | Precision potentiometer (independent) |
| Housing | Waterproof — resistant to pressure water, mud, oil |
| Warranty | 3 Years 100% Warranty + 10 Years Service & Maintenance |
Operating voltage, ingress protection (IP) rating, motor dimensions/weight, torque capacity and compatible tractor models are not yet confirmed — these will be added once verified.
Use Cases
| Application | Benefit |
|---|---|
| ◆ Field work — plough | Consistent tillage quality with precise depth control. |
| ◆ Cultivator & harrow | Automatic raise-lower at headlands via electronic Lift-O-Matic. |
| ◆ Fertilizer spreading / spraying | Constant height and depth — homogeneous distribution. |
| ◆ Trailer & load work | Remote hydraulic management via joystick, operator comfort. |
What's in the Box
✓ ELF-850 Main Control Unit
✓ 2× HCT402 Servo Motor
✓ Joystick Control Unit
✓ Fender Switches
✓ Motor Mounting Brackets & Rear Mounting Plates
✓ Mounting Screws & Cable Set
Demo Video
AXI ELF-850 — with dual servo motors, your rear arms are now genuinely 100% electric.