Week 17: Applications and Implications

1. Applications and Implications

My final project is a robotic gripper that explores how mechanical design, electronics, and programming can work together to pick up and hold objects. The main focus is to build a functional prototype that combines a gear-based gripping mechanism with servo actuation and a microcontroller-based control system.

While developing the project, I have been exploring how the mechanical components fit together, how the gears transfer movement, and how the servo can control the opening and closing of the gripper. The project also gives me the chance to apply the digital fabrication techniques I have learned during Fab Academy to a real physical product.

The gripper could be useful in educational robotics, small-scale automation, and object-handling experiments. However, what it can actually do will depend on the final mechanism, the available torque, and the test results. At this stage, my aim is to develop and evaluate the prototype, not to claim that it is ready for industrial use.

2. Robotic Gripper: Final Project Plan

What will it do?

The robotic gripper will use a motor-driven mechanism to open and close its gripping fingers, so it can pick up and hold suitable objects. The gear mechanism coordinates the movement of the fingers, while a servo and microcontroller control the actuation.

My main goal is controlled, smooth movement and a reliable grip. I will test the mechanism with suitable objects to understand its limits and find where it needs improvement.

Who's done what beforehand?

Robotic grippers are already used in industrial automation, research labs, and educational robotics. Existing designs take different approaches, including parallel-jaw grippers, multi-finger grippers, gear-driven mechanisms, and servo-operated linkages.

These mechanisms are useful references for finger movement, gear alignment, gripping force, and mechanical stability. My project builds on these established principles, while letting me design and fabricate my own mechanical arrangement and integrate the electronics myself.

What sources will you use?

I will refer to the following sources during development:

Existing robotic grippers: to study finger geometry, gripping mechanisms, gear arrangements, and overall construction.
MG90S servo datasheet: to understand operating voltage, torque ratings, range of movement, and current requirements.
Seeed Studio XIAO RP2040 documentation: to understand pin connections, programming, and servo control.
PCB and electronics references: to guide circuit design, component placement, and board fabrication.
Fab Academy documentation: for the fabrication methods, machining processes, PCB milling, electronics, and prototyping techniques covered during the course.

These references will help me make informed decisions while designing and troubleshooting, instead of relying only on trial and error.

What will you design?

I will design the mechanical structure of the gripper: the base, gripping fingers, gear mechanism, linkages, and the mounts for the servo and other components.

This includes 3D modelling each part and checking how they fit together before and during fabrication. On the electronics side, I will work on the circuit and PCB layout for the control system, along with the wiring and the code that operates the servo.

Throughout, I want to keep the design practical to fabricate, assemble, test, and modify.

Materials, components, sourcing and cost

The project combines fabricated mechanical parts with commercially available electronic components.

Material / component	Purpose	Source	Est. cost (₹)	Status
3D-printed parts (PLA)	Gripper body, fingers, and mechanical supports	Fab Lab	150–300	Fabricated / being refined
Gears and linkages	Transfer motion to the gripping fingers	3D-printed or bought	0–200	Fit and movement need testing
MG90S servo motor	Drives the gripping mechanism	Robu.in / ElectronicsComp	200–300	Standalone testing
Seeed Studio XIAO RP2040	Runs the control code	Robu.in / Seeed Studio	450–650	Used for standalone servo testing
PCB and electronic components	Provide the planned control and connection system	Fab Lab inventory	150–400	Design and integration in progress
Fasteners and mounting hardware	Secure the mechanical assembly	Local hardware store	100–250	As required
Wires and regulated power supply	Power and connect the control system	Fab Lab inventory / Robu.in	300–600	Being checked during testing

Costs are estimates based on typical Indian prices (≈ ₹1,350–2,700 in total), not actual receipts. I will replace them with real costs as I confirm them, and update the final bill of materials and total project cost once the components and mechanical design are finalised. This will include fabrication material, machining, electronic components, and any extra parts needed during iteration.

What parts and systems will be made vs bought?

Made:

Custom 3D-modelled and fabricated gripper components.
Mechanical supports and mounting features.
A custom PCB, if the final board is fabricated as planned.
The software and control code for the project.

Bought:

Servo motor and microcontroller.
Electronic components and connectors.
Gears, shafts, fasteners, or other standard mechanical hardware where appropriate.
Power supply and wiring.

This lets me focus on designing the parts that define the mechanism, while using reliable, commercially available components for actuation and control.

What processes will be used?

The project combines digital design, fabrication, electronics, and programming:

3D modelling: to develop the mechanical parts and check how components fit.
3D printing: to fabricate custom mechanical components and iterate on the design.
CNC machining: to explore making suitable mechanical parts where needed.
Lathe machining: for custom components that need rotational geometry or an accurate fit (see Wildcard Week).
PCB design and milling: to develop and fabricate the electronics board.
Soldering and wiring: to assemble and connect the electronic components.
Embedded programming: to control the servo and test movement.
Mechanical assembly and testing: to evaluate gear movement, alignment, resistance, and gripping performance.

Not every process is needed for every component. I will document which methods were used for the final parts and what changed during fabrication.

What questions need to be answered?

Can the gear mechanism open and close the gripper smoothly?
Is the selected servo powerful enough for the required movement under load?
How can I reduce friction, misalignment, and mechanical resistance?
Are the fabricated components strong enough for repeated testing?
Can the electronics and power supply run the servo reliably?
How should the PCB and wiring be integrated into the physical structure?
What range of object sizes and shapes can the gripper handle?
Can the gripper repeatedly hold an object without slipping?
Which mechanical or electronic changes will improve the final prototype?

How will it be evaluated?

I will evaluate the project through practical tests, not just by how the 3D model looks.

The main evaluation criteria are:

Movement: does the gripper open and close through its intended range?
Smoothness: can the servo move the mechanism without excessive jitter or resistance?
Grip: can the fingers hold suitable objects securely?
Mechanical fit: do the gears, linkages, and supports stay aligned during operation?
Reliability: can the mechanism repeat its movement consistently?
Electronics: do the controller, power supply, and servo connections work reliably?
Fabrication quality: do the manufactured parts fit together as intended?
Documentation: are the design, fabrication process, code, and test results clearly recorded?

The results will show the strengths and limitations of the prototype and what further development it needs.

Current status

The project has moved through concept development, 3D modelling, mechanical fabrication, and initial electronics work. I have explored the gear-based gripping mechanism, made physical components using fabrication and machining processes, and started developing the control system.

I am currently testing the MG90S servo with the XIAO RP2040 on its own, and working on smooth movement while accounting for the resistance of the mechanical assembly. Next, I will refine the component fit, complete the mechanical and electronic integration, and test the gripper with suitable objects.

The project is still in development. My immediate priority is to get the mechanism working reliably, evaluate its actual gripping performance, and document the changes I make during testing.