Gears and transmission
4-DOF Robotic Arm (Exploded Layout)
- Bounding box
- 795.0 × 90.0 × 62.5 mm
- Engine
- Precision B-rep
- Parameters
- 42
- Published
- November 2, 2026
Download
Free to download and use. See the terms.
The prompt
```text Act as a professional mechanical engineer, electronics engineer, robotics engineer, and CAD designer. Design a fully functional 4 Degrees of Freedom (4-DOF) robotic arm for 3D printing and Arduino UNO control. General Requirements: • The robotic arm must use four MG90S metal gear servo motors (180° rotation). • Degrees of Freedom: 1. Base rotation: one MG90S servo providing 180° rotation. 2. Shoulder joint: one MG90S servo for arm lifting (flexion/extension). 3. Elbow joint: one MG90S servo for forearm movement (flexion/extension). 4. Gripper: one MG90S servo to open and close the gripper. The design must be lightweight to match the limited torque of MG90S servos. Approximate Dimensions: • Base height: 50 mm • Base diameter: 90 mm • Upper arm length: 120 mm • Forearm length: 110 mm • Gripper opening: 45 mm • Total weight of the robotic arm should be under 250 grams. Material: • PLA for all printed parts. • Minimum wall thickness: 3 mm. • Internal reinforcements where needed. • Use M2 and M3 screws and nuts. Generate the following: 1. Complete 3D CAD model. 2. Fully dimensioned engineering drawings. 3. STL files ready for 3D printing. 4. Editable STEP files. 5. Exploded assembly view. 6. Bill of Materials (BOM). 7. Complete hardware list (screws, nuts, spacers, bearings if required). 8. Step-by-step assembly instructions. 9. Complete electrical wiring diagram. 10. Arduino UNO wiring schematic. 11. Complete Arduino code using the Servo.h library. 12. Servo pin assignments: • Base Servo → Pin 3 • Shoulder Servo → Pin 5 • Elbow Servo → Pin 6 • Gripper Servo → Pin 9 13. Use an external regulated 5V power supply for the servos with a common ground shared with the Arduino. 14. Explain how the entire system works. 15. Perform an approximate torque analysis and verify that MG90S servos are sufficient for the proposed lightweight design. 16. Optimize the structure to minimize weight while maximizing rigidity. 17. Design all servo mounts specifically for MG90S servos with accurate mounting hole dimensions. 18. Ensure all printed parts are easy to assemble and require minimal support during 3D printing. 19. Include recommended print orientation and print settings for each part. 20. Design the gripper to securely grasp small lightweight objects. The final output should include: • High-quality rendered images of the robotic arm. • Complete CAD assembly. • Mechanical blueprints with dimensions. • Electrical wiring diagram. • Exploded assembly diagram. • STL files. • STEP files. • Arduino source code. • Bill of Materials. • Assembly guide. • Manufacturing instructions. The robotic arm should have a professional appearance, be mechanically stable, easy to manufacture, and optimized for educational and demonstration purposes. ```
Parameters
| Name | Value | Range |
|---|---|---|
| Base Diameter | 90 mm | 40 – 150 |
| Base Height | 50 mm | 20 – 100 |
| Servo Cavity Length | 24 mm | 20 – 40 |
| Servo Cavity Width | 13 mm | 10 – 20 |
| Servo Cavity Depth | 40 mm | 10 – 50 |
| Turret Diameter | 50 mm | 20 – 80 |
| Turret Height | 25 mm | 10 – 50 |
| Turret Bore Diameter | 5 mm | 2 – 10 |
| Bracket Length | 60 mm | 40 – 100 |
| Bracket Width | 40 mm | 30 – 80 |
| Bracket Height | 25 mm | 15 – 50 |
| Wall Thickness | 3 mm | 1 – 10 |
| Slot Length | 54 mm | 10 – 90 |
| Slot Width | 13.5 mm | 10 – 30 |
| Slot Depth | 22 mm | 5 – 30 |
| Upper Arm Length | 120 mm | 60 – 200 |
| Upper Arm Width | 20 mm | 10 – 40 |
| Upper Arm Thickness | 15 mm | 5 – 30 |
| Hole Diameter | 3.2 mm | 1 – 6 |
| Hole Offset from End | 10 mm | 5 – 30 |
| Fillet Radius | 3 mm | 0 – 10 |
| Elbow Bracket Length | 40 mm | 20 – 80 |
| Elbow Bracket Width | 35 mm | 20 – 70 |
| Elbow Bracket Height | 30 mm | 15 – 50 |
| Wall Thickness | 3 mm | 1 – 10 |
| Hole Diameter | 3.2 mm | 1 – 6 |
| Forearm Length | 110 mm | 50 – 200 |
| Forearm Width | 18 mm | 10 – 40 |
| Forearm Thickness | 15 mm | 5 – 30 |
| Hole Diameter | 3.2 mm | 1 – 6 |
| Hole Offset from End | 8 mm | 5 – 30 |
| Fillet Radius | 3 mm | 0 – 10 |
| Base Length | 45 mm | 20 – 80 |
| Base Width | 30 mm | 15 – 60 |
| Base Thickness | 10 mm | 5 – 20 |
| Hole Diameter | 3.2 mm | 1 – 6 |
| Finger Length | 50 mm | 20 – 80 |
| Finger Width | 8 mm | 3 – 15 |
| Finger Thickness | 3 mm | 1 – 8 |
| Opening Span | 45 mm | 20 – 80 |
| Tip Radius | 4 mm | 1 – 10 |
| Layout Gap | 100 mm | 50 – 300 |
Every value above is a live dimension. Open a model like this in the editor and each one becomes a slider you can drag before exporting.
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