Adjustable SHT31 / SHT41 Enclosure Sensor Mount for 3D Printer Monitoring

I built a custom enclosure for my 3D printer and wanted to monitor temperature and humidity at multiple positions inside the enclosure to better understand and optimize printing conditions for different filament types such as PLA, PETG and PC.

This model is a compact adjustable mounting enclosure for Adafruit SHT31 temperature and humidity sensors, inspired by the design from:

https://www.printables.com/model/957379-sht41-casemount-sht40-and-sht45-also

Instead of fixed mounting, this version is designed to attach to a threaded rod, allowing the sensor height to be adjusted easily. This makes it possible to measure environmental conditions at different locations inside the enclosure:

• near the print area

• higher in the enclosure

• or anywhere in between

This helps detect temperature gradients and improves enclosure tuning for different materials.

In my setup:

• two sensors are installed inside the enclosure

• both connected to an ESP32 microcontroller

• readings displayed on a small OLED screen

• one sensor measures near the print zone

• one sensor measures near the top of the enclosure

This allows accurate monitoring and optimization of enclosure conditions during printing.

To keep the installation clean and practical, I also designed a separate control box mounted directly to the printer. The control box allows the printer and enclosure electronics to be powered on and off and contains the ESP32 control electronics. The ESP32 is connected over WiFi and integrated into Home Assistant using MQTT. A separate pushbutton mounted on one of the enclosure walls allows switching between different filament profiles.

For the wiring between the sensors, push button and the control box I used CAT6 cable. This keeps the wiring compact and modular while allowing power, I²C communication and switch signals to run through a single cable bundle.

Inside Home Assistant, I created separate enclosure profiles for different filament types such as PLA, PETG and PC. Each profile contains configurable lower and upper enclosure temperature limits. Based on the currently selected filament profile, Home Assistant can immediately indicate whether the enclosure temperature is within the optimal range for printing.

The setup currently supports:

• live enclosure temperature and humidity monitoring

• switching filament profiles directly from Home Assistant

• adjustable temperature ranges per filament type

• status indication showing whether enclosure conditions are optimal

Sensor data is also forwarded (via InfluxDB) to Grafana for long-term monitoring and visualization. This makes it possible to analyze enclosure warm-up behavior, temperature gradients and humidity stability during printing. The graphs clearly show that the enclosure performs as intended and maintains stable environmental conditions for different materials.

Designed for:

• Adafruit SHT31 breakout

• Adafruit SHT40 breakout

• Adafruit SHT41 breakout

• Adafruit SHT45 breakout

Other breakout boards with similar mounting hole spacing may also fit.

Features

• adjustable mounting height using threaded rod

• compact protective enclosure

• airflow-friendly sensor exposure

• cable exit opening included

• supports multi-sensor enclosure monitoring setups

• ideal for ESP32 climate monitoring projects

Hardware used

• 2× Adafruit SHT31 sensors

• ESP32 microcontroller

• I²C OLED display

• threaded rod (M3 or M4)