projects / 4

Robotic Claw Machine

actuation 3-Axis Motorized Gantry + Claw controller Arduino / Microcontroller interface 2-Axis Joystick + Pushbutton course 1st Year Mechatronics Robotics

A fully functional desktop robotic claw machine designed and built for a first-year Mechatronics robotics competition. Features a custom 3-axis rack-and-pinion Cartesian gantry, dual-axis analog joystick control, and a motorized 3-jaw linkage claw mechanism.

System Overview: 3-axis Cartesian gantry with articulating claw linkage and custom EV3 joystick controls.
Motorized Claw Carriage Suspended over Candy Prize Hopper
Dual-Axis Joystick Control Interface Mounted on Cabinet Frame
• LEGO Joystick: Built final joystick using LEGO parts, closely matching the CAD design structure. [VIDEO]
• LEGO Joystick: Built final joystick using LEGO parts, closely matching the CAD design structure. [VIDEO]
• LEGO Joystick: Built final joystick using LEGO parts, closely matching the CAD design structure. [VIDEO]
• Ribbon Routing: Mounted claw onto axis and joystick onto wooden frame, then routed LEGO ribbons to EV3.
• Ribbon Routing: Mounted claw onto axis and joystick onto wooden frame, then routed LEGO ribbons to EV3.
[01/08] System Overview: 3-axis Cartesian gantry with articulating claw linkage and custom EV3 joystick controls.

01Mechanical Design & CAD Assembly

Comprehensive SolidWorks 3D CAD modeling, multi-body kinematics, tolerance stack-up analysis, and assembly architecture.

01.1 2-Axis Joystick Kinematics & Ergonomic Modeling

SolidWorks 3D kinematic model of a dual-axis analog joystick mechanism delivering intuitive multi-directional gantry control.

Joystick CAD: Designed in SolidWorks to visualize joystick movement and ensure a compact fit on the EV3.
Joystick CAD: Designed in SolidWorks to visualize joystick movement and ensure a compact fit on the EV3.
Joystick CAD: Designed in SolidWorks to visualize joystick movement and ensure a compact fit on the EV3.
[01/03] Joystick CAD: Designed in SolidWorks to visualize joystick movement and ensure a compact fit on the EV3.

01.2 Dual-Axis Tilting Gimbal Mechanism

Orthogonal pivot plate geometry supporting two independent rotation axes for continuous joystick motion.

Tilting Plate: Connects at two points and supports the joystick at two others for two-directional movement.
Tilting Plate: Connects at two points and supports the joystick at two others for two-directional movement.
Tilting Plate: Connects at two points and supports the joystick at two others for two-directional movement.
[01/03] Tilting Plate: Connects at two points and supports the joystick at two others for two-directional movement.

01.3 EV3 Direct-Mount Interface & Button Actuation

Custom bracket mating directly onto the LEGO Mindstorms EV3 brick, aligning mechanical joystick throws with physical push buttons.

Joystick EV3 Mount: Joystick mounts directly onto the EV3, with buttons aligned for input as the joystick tilts.
Joystick EV3 Mount: Joystick mounts directly onto the EV3, with buttons aligned for input as the joystick tilts.
Joystick EV3 Mount: Joystick mounts directly onto the EV3, with buttons aligned for input as the joystick tilts.
[01/03] Joystick EV3 Mount: Joystick mounts directly onto the EV3, with buttons aligned for input as the joystick tilts.

02Prototyping, 3D Printing & Fabrication

Rapid prototyping iterations, slicing optimization (Bambu Studio / PrusaSlicer), material selection (PLA / PETG / Carbon Fiber), and precision fit checks.

02.1 LEGO Gimbal Joystick Fabrication & Tactile Testing

Constructing physical joystick gimbal assembly from LEGO Technic elements, validating smooth return-to-center and tactile switch actuation.

• LEGO Joystick: Built final joystick using LEGO parts, closely matching the CAD design structure. [VIDEO]
• LEGO Joystick: Built final joystick using LEGO parts, closely matching the CAD design structure. [VIDEO]
• LEGO Joystick: Built final joystick using LEGO parts, closely matching the CAD design structure. [VIDEO]
• LEGO Joystick: Built final joystick using LEGO parts, closely matching the CAD design structure. [VIDEO]
• LEGO Joystick: Built final joystick using LEGO parts, closely matching the CAD design structure. [VIDEO]
• LEGO Joystick: Built final joystick using LEGO parts, closely matching the CAD design structure. [VIDEO]
• LEGO Joystick: Built final joystick using LEGO parts, closely matching the CAD design structure. [VIDEO]
[01/07] • LEGO Joystick: Built final joystick using LEGO parts, closely matching the CAD design structure. [VIDEO]

02.2 Cartesian Gantry Rails & Linear Axis Prototyping

Dual-axis motorized gantry carriage running along rigid linear guide rails for responsive XY positioning over the prize bay.

• LEGO Tracks: Prototyped an alternative claw axis system using LEGO for the claw’s XY axis movement.
• LEGO Tracks: Prototyped an alternative claw axis system using LEGO for the claw’s XY axis movement.
• LEGO Tracks: Prototyped an alternative claw axis system using LEGO for the claw’s XY axis movement.
[01/03] • LEGO Tracks: Prototyped an alternative claw axis system using LEGO for the claw’s XY axis movement.

02.3 Claw Gripper Prototypes & Kinematic Evolution

Iterating through single-motor vs dual-motor claws, evaluating four-finger vs two-finger designs for grip strength and payload stability.

• LEGO Claw: Built two prototypes—one with a single motor for both claw grab and Z movement, and the second prototype with separate motors for claw grabbing and lowering, allowing for more accurate control.
• LEGO Claw: Built two prototypes—one with a single motor for both claw grab and Z movement, and the second prototype with separate motors for claw grabbing and lowering, allowing for more accurate control.
• LEGO Claw: Built two prototypes—one with a single motor for both claw grab and Z movement, and the second prototype with separate motors for claw grabbing and lowering, allowing for more accurate control.
• Claw Prototype 1 & 2: Different concepts including four-finger claw and extended gripping mechanisms.
• Claw Prototype 1 & 2: Different concepts including four-finger claw and extended gripping mechanisms.
• Claw Prototype 1 & 2: Different concepts including four-finger claw and extended gripping mechanisms.
[01/06] • LEGO Claw: Built two prototypes—one with a single motor for both claw grab and Z movement, and the second prototype with separate motors for claw grabbing and lowering, allowing for more accurate control.

02.4 Dual-Motor Articulated Claw & Pulley Winch Rig

Final winning design featuring independent motors for vertical hoist drop and articulated claw gripping with high-friction silicone pads.

• Final Claw: Used two motors with a wider two-finger claw and a pulley system for claw vertical drop control.
• Final Claw: Used two motors with a wider two-finger claw and a pulley system for claw vertical drop control.
• Final Claw: Used two motors with a wider two-finger claw and a pulley system for claw vertical drop control.
• Final Claw: Used two motors with a wider two-finger claw and a pulley system for claw vertical drop control.
[01/04] • Final Claw: Used two motors with a wider two-finger claw and a pulley system for claw vertical drop control.

02.5 Mechanism Ideation Sketches & Stroke Geometry

Hand-drawn kinematic diagrams and trigonometric angle calculations optimizing joystick pivot throws and claw finger leverage.

• Parts Sketch: Initial sketches showing claw machine concepts, early prototypes, and overall design process.
• Parts Sketch: Initial sketches showing claw machine concepts, early prototypes, and overall design process.
• Joystick Calculations: Calculated joystick motion and button press positions to support the CAD design.
• Joystick Calculations: Calculated joystick motion and button press positions to support the CAD design.
[01/04] • Parts Sketch: Initial sketches showing claw machine concepts, early prototypes, and overall design process.

03Electrical, Firmware & Hardware Integration

Schematic capture, PCB routing, sensor interfacing, actuator control, and embedded firmware implementation.

03.1 Multi-Axis Ribbon Harness & Cable Management

Overhead ribbon cable routing with flex loops and anchor brackets to prevent snagging during high-speed gantry travel.

• Ribbon Routing: Mounted claw onto axis and joystick onto wooden frame, then routed LEGO ribbons to EV3.
• Ribbon Routing: Mounted claw onto axis and joystick onto wooden frame, then routed LEGO ribbons to EV3.
[01/02] • Ribbon Routing: Mounted claw onto axis and joystick onto wooden frame, then routed LEGO ribbons to EV3.

03.2 RobotC Control Firmware & Automated Cycle Testing

Embedded firmware written in RobotC (C++) implementing smooth joystick motor mapping, limit switch homing, and automatic drop sequences.

• EV3 Code Testing: Verified all functions including claw lift, drop, grab, and joystick control. Adjusted wiring to prevent tangling during movement, tested object pickup and drop sequence. [VIDEO]
• EV3 Code Testing: Verified all functions including claw lift, drop, grab, and joystick control. Adjusted wiring to prevent tangling during movement, tested object pickup and drop sequence. [VIDEO]
• EV3 Code Testing: Verified all functions including claw lift, drop, grab, and joystick control. Adjusted wiring to prevent tangling during movement, tested object pickup and drop sequence. [VIDEO]
[01/03] • EV3 Code Testing: Verified all functions including claw lift, drop, grab, and joystick control. Adjusted wiring to prevent tangling during movement, tested object pickup and drop sequence. [VIDEO]