Arduino Uno Enclosure: UNO, 16x2 LCD & HX711

Arduino Force Gauge Enclosure: UNO, 16x2 LCD & HX711 Casing

Description

This is a robust, two-part (base and lid) 3D-printed enclosure designed specifically to house the essential electronics for a DIY digital force gauge, laboratory test stand, or high-precision weighing scale. It provides a clean, professional, and secure housing for your Arduino Uno, 16x2 I2C LCD screen, and HX711 load cell amplifier module.

Created by an Engineering and Design & Technology HOD (for KS3-KS5 education), this design prioritizes strong, reliable construction using professional assembly methods, making it perfect for student projects, prototyping, and long-term use in a workshop environment. The design is simple, effective, and ready to be customized (CAD shown in images).

Key Features & Design Highlights 

• Optimized for Core Components: Custom-fit mounting for the three primary components:
  • Arduino Uno (Standard R3 footprint).
  • 16x2 Character LCD with an I2C Backpack.
  • HX711 Load Cell Amplifier Module.
• Complete Weld-Mounted System: All three circuit boards (Uno, HX711, and the LCD screen) sit on integrated mounting posts designed for a weldable/heat-set mounting technique. This ensures a secure, low-profile, and vibration-resistant fit for all internal electronics.
• Professional Fastening System: Screw holes are precisely sized for four M4 brass threaded inserts (heat-set), providing strong, reusable, and professional thread mounting points for securing the lid to the base.
• Ample Wiring Space: The base features high-volume internal space to neatly manage and coil excess wiring, keeping the electronics tidy and preventing stress on connections.
• Thermal Management: Integrated ventilation slots are strategically placed on the lid to allow for passive cooling and prevent heat build-up inside the enclosure.
• User Interface Access:
  • A precision-sized hole with a 7mm diameter is provided on the lid for mounting a tactile reset/function button (e.g., to zero the sensor or clear the Max Force reading).
  • A cut-out is included for running an extension cable to external peripherals, such as a load cell, external power, or other sensors.

Printing and Assembly Guide

1. Printing Recommendations

• Material: PLA is suitable, but PETG or ABS is highly recommended for increased durability, dimensional stability, and better heat resistance (especially when using heat-set inserts).
• Layer Height: 0.2mm for general prints.
• Infill: 15-25% Grid or Honeycomb.
• Supports: No supports are needed.

• Component	Quantity	Specification
  Brass Inserts	4	M4 x 8.1mm (Recommended Standard Size)
  Screws	4	M4 machine screws, minimum 8mm length (to secure the lid)
  Button	1	Momentary tactile button (7mm shank diameter)
  Electronics	1 of each	Arduino Uno R3, 16x2 I2C LCD, HX711 Module

3. Assembly Instructions

1. Install Inserts: Using a soldering iron with a heat-set tip, install the four M4 brass threaded inserts into the corner mounting posts of the base.
2. Mount Boards (Weld): Place the Arduino Uno, HX711, and the 16x2 LCD (into the lid) onto their respective mounting posts. Secure them by gently pressing a heated soldering iron tip onto the plastic posts to slightly melt/deform the plastic over the PCB holes (welding). Note: Ensure boards are wired before mounting.
3. Install Button & Cable: Install the 7mm button into the lid hole and feed the load cell/peripheral cable through the designated hole.
4. Final Assembly: Align the lid with the base and secure with the four M4 machine screws into the brass inserts.