HCT402-D Differential Drive Kit - Joystick Hydraulic Control

Turns manual hydraulic travel levers into single-joystick differential drive. 2× 20 kgf servos, proportional mixing firmware, 360° pivot turn, 12V/24V.

The HCT402-D Differential Drive Kit lets a single joystick operate the two travel levers of a tracked or dual hydraulic-motor vehicle. Nothing inside the hydraulic circuit is modified: a servo motor is mounted on each manual lever, and the joystick in the cab drives both of them proportionally and simultaneously.

The kit combines two AXI HC402 servo motors, a two-axis industrial joystick and the custom mixing firmware that ties them together. Push the stick forward and both levers move forward; push it fully to one side and one lever goes forward while the other reverses, pivoting the vehicle 360° on the spot; lean it slightly to one side while travelling and the inner motor slows down for a smooth turn.

Bring the feel of the mechanical levers into the cab. Instead of balancing two stiff levers with both hands, you get millimetric, comfortable control from one stick.

HCT402-D at a Glance

Motors
2 × HC402 servo
Force
~20 kgf per motor
Voltage
12V & 24V (7–40V)
Control
Two-axis joystick
Steering
360° pivot turn
Protection
IP67 + reverse polarity

How Differential (Skid-Steer) Drive Works

Differential drive steers a vehicle by running its left and right sides at different speeds rather than by turning a wheel. HCT402-D's firmware reads both joystick axes and produces an independent command for each lever:

Joystick Left lever Right lever Vehicle behaviour
Forward Forward Forward Straight ahead — speed follows stick travel
Backward Reverse Reverse Straight back — proportional
Full right Forward Reverse Pivot right on the spot (360°)
Full left Reverse Forward Pivot left on the spot (360°)
Forward + slight right Faster Slower Smooth right turn — inner side slows
Forward + slight left Slower Faster Smooth left turn
Centred Neutral Neutral Levers return to centre, motion stops

Highlight Features

One joystick, two levers
The firmware mixes the fore/aft and left/right axes into two independent lever commands.
True proportional motion
Lever angle follows stick travel. A parabolic curve gives fine control mid-stick and speed at the ends.
360° pivot turn
One track forward, the other in reverse — the machine turns within its own footprint.
Dead-man button
No motion is produced unless the enable button on the joystick is held. Accidental contact stays harmless.
Fast response
The delay between stick movement and lever reaction is imperceptible; direction changes answer instantly.
Hydraulics untouched
Valve block, hoses and levers stay in place. With the power off, the levers can still be worked by hand.

What's in the Kit

2 × HC402 high-torque servo motors
~20 kgf per lever, 7–40V wide input, IP67 housing, reverse-polarity protected.
Two-axis industrial joystick
Wired, boot-sealed, ergonomic grip with an enable (dead-man) button.
Differential drive firmware
Mixing algorithm tuned per vehicle: direction, speed ratio and response curve.
Mounting hardware
Brackets and fasteners matched to the lever geometry of your valve block.
Wiring and documentation
Supply and joystick harness, wiring diagram and commissioning instructions.

Installation

  1. Mount the motors
    Both servos are bracketed onto the travel levers without restricting their mechanical range.
  2. Power and harness
    The system runs from the vehicle battery (12V or 24V); the joystick cable is routed into the cab.
  3. Lever range calibration
    Each motor learns the mechanical end points of its lever so no pressure is held against the stops.
  4. Direction and mixing setup
    Axes are inverted in software to match motor orientation, then a test drive finalises the response curve.

Applications

Tracked machines
Travel levers driven from a manual hydraulic valve
  • Tracked carriers and mini dumpers
  • Tracked drilling and boring chassis
  • Tracked cranes and access platforms
  • Tracked orchard, spraying and garden machines
  • Snow and off-road tracked carriers
Dual-motor wheeled vehicles
A separate hydraulic motor on each wheel
  • Skid-steer loaders
  • Floor treatment and cleaning machines
  • In-plant tugs and carriers
  • Agricultural and greenhouse vehicles
Special-purpose platforms
Project-based builds and prototypes
  • Military and special-purpose tracked platforms
  • Remotely driven robotic chassis
  • R&D and prototype vehicles
  • Stationary hydraulic test rigs

Wired or Wireless?

Optional wireless version

When the control station sits away from the hydraulics

The standard kit ships with a wired joystick — the most stable and economical answer when the cab is close to the valve block. Where the control has to be separate from the machine, the same drive logic can be delivered wirelessly.

AXI's proprietary XRF encrypted RF link
Motion stops safely on signal loss
Suited to remotely operated platforms
Quoted per project

Warranty & Support

24 Months
Full warranty
Covers the servo motors, joystick and all electronic components.
10 Years
Spare parts & service
Support continues long after the warranty period ends.
100%
Designed by AXI
Hardware and firmware developed in Türkiye and adapted per vehicle.

Frequently Asked Questions

What exactly does HCT402-D do?

It drives the two travel levers of your hydraulic valve with a servo motor each, and manages both from a single joystick using differential drive logic — one hand instead of two, fully proportional.

Does my hydraulic system need modification?

No. Valve block, hoses and levers stay as they are; the motors bolt on externally. No oil line is opened, and with the power off the levers still work by hand.

How does the pivot turn work?

Leaning the stick sideways commands one lever forward and the other in reverse, so the tracks counter-rotate and the machine turns within its own footprint — proportionally, so a small lean gives a slow pivot.

What is the enable button for?

It is a dead-man safety button. Unless it is held, joystick movement produces no command — accidental contact in the cab cannot start motion.

12V or 24V?

The system runs on 7–40V, so 12V and 24V batteries are supported directly. Control characteristics hold up even as the battery drops, and reversed supply leads draw no current and cause no damage.

Can it move more than two levers?

The standard kit covers the two travel levers. Extra axes from the same motor family can be added for bucket, tipper or boom functions; the control layout is then planned per project.

Why is there no price listed?

Mounting hardware and firmware tuning depend on the valve type, lever geometry and cab distance, so the kit is quoted individually. Send photos of the machine and a close-up of the valve block and we reply with price and lead time the same day.

Product Video

HCT402-D — dual-motor differential drive demonstration

HCT402-D — AXI Teknoloji's single-joystick differential drive solution for tracked and dual hydraulic-motor vehicles, built on the HC402 servo motor.