Week 12 — Mechanical and machine design

This week’s topic: Mechanical and machine design.

Group assignment

In Shenzhen Chaihuo, our group developed a compact vending-machine concept for XIAO boards to explore machine design as a full system problem: interaction flow, electronics control, actuation, and mechanical reliability.

Work objective

Define a practical machine concept useful in a makerspace context.
Break the concept into structure, control, sensing, and actuation modules.
Plan staged testing before full mechanical-electrical integration.

1) Idea generation and requirement framing

We started from use-case discussion and translated it into clear requirements: compact size, controlled single-item dispensing, readable interaction flow, and prototype-friendly build cost.

Initial brainstorming for xiao vending machine — Concept photo A - Early brainstorming on machine purpose and value.

Discussion of requirements and user flow — Concept photo B - Requirement and user-flow discussion stage.

2) Planning and architecture definition

The selected architecture uses a vertical storage column with gravity feed and a servo-driven gate. RFID input triggers dispensing logic on the controller side.

Planning board with machine sketch and workflow — Planning photo A - System sketch and development workflow mapping.

Component list materials and assembly notes — Planning photo B - Component/material planning and assembly notes.

3) Component selection and subsystem roles

Part	Role in the prototype
Wio Terminal	Main controller with local display for state feedback.
Grove RFID reader	User input module to trigger transaction and dispense sequence.
STS3215 serial bus servo	Actuator controlling gate motion and dispensing position.
Acrylic + 3D-printed structure	Visible enclosure, storage column, and motion interfaces.

Wio terminal as central controller — Component photo A - Wio Terminal chosen as control and display core.

STS3215 serial bus servo for gate actuation — Component photo B - Serial-bus servo selected for gate movement.

Servo accessories and mounting parts — Component photo C - Servo accessories evaluated for mounting and linkage.

Grove rfid reader used as interaction input — Component photo D - RFID module for card-based interaction flow.

4) Mechanical interface and integration note

A custom 3D-printed arm was used to couple servo rotation to gate motion. This interface was critical for preventing double-dispense behavior and keeping release motion repeatable.

3d printed servo arm for gate drive — Integration photo - Printed linkage arm connecting actuator to gate latch.

Result summary

Established a feasible machine concept for controlled XIAO dispensing.
Defined subsystem boundaries across structure, control, and actuation.
Identified integration-critical mechanical interfaces early in the process.
Created a practical base for later full assembly and refinement.