Voron Electronics Bay Cooling — Best Fan Mods and Enclosure Cooling

Cooling Mod Electronics Klipper V2.4 Trident V0.2

The electronics bay on a Voron printer houses the controller board, stepper drivers, Raspberry Pi or equivalent, and the power supply unit. These components generate significant heat, and the enclosed design of Voron printers means that heat has nowhere to go without active cooling. Inadequate electronics bay cooling is one of the most common root causes of skipped steps, TMC driver thermal shutdowns, Pi throttling, and print failures — especially in warm environments or when the printer chamber is heated. This guide covers every popular electronics bay cooling mod for Voron printers.

Last updated: May 2025. We cover fan upgrades, ducted intake systems, filtered cooling, active exhaust mods, and Klipper-based temperature-aware fan control. All pricing reflects China-direct sourcing. Difficulty ranges from easy to moderate.

Why Electronics Bay Cooling Matters

Voron printers run their electronics in a sealed compartment below the build chamber. On a V2.4, the electronics bay sits directly under the heated bed. When the bed is at 100C-110C for ABS printing, the electronics bay can reach 45-55C without active cooling. This has several consequences:

• TMC driver thermal shutdown: TMC2209 and TMC5160 drivers enter thermal shutdown at approximately 100C internal die temperature. At 50C ambient in the electronics bay, the drivers can reach shutdown temperature during long prints, causing one or more axes to stop mid-print. This manifests as a print with one axis that suddenly stopped moving, leaving a scar across the part.
• Raspberry Pi throttling: The Raspberry Pi 4 throttles its CPU at 80C. A Pi inside a poorly ventilated electronics bay running Klipper + Mainsail/OctoPrint can reach 80C within 30 minutes of bed heating. Throttling causes micro-stutters in USB communication, which can cause print artefacts or communication timeouts.
• Stepper motor driver current derating: Most TMC drivers reduce their output current as ambient temperature rises. This means your carefully tuned motor current values may be insufficient when the electronics bay is hot, leading to skipped steps.
• PSU lifespan reduction: Switching power supplies lose efficiency and lifespan at elevated temperatures. A PSU running at 50C continuously has a significantly shorter MTBF than one at 30C.
• USB and CAN bus instability: USB controllers and CAN bus transceivers can lose signal integrity at high temperatures, causing intermittent connection drops that are extremely difficult to diagnose.

Good electronics bay cooling solves all of these problems. It keeps component temperatures in the safe operating range, extends hardware lifespan, and eliminates the most cryptic and intermittent failure modes in Voron printers.

Electronics Bay Cooling Mods Compared

1. Fan Upgrade — Stock Location Replacement

The simplest upgrade. Replace the stock electronics bay fan with a higher-performance unit. Stock Voron electronics bay fans are typically 80mm or 92mm 24V axial fans. Swapping to a higher-static-pressure fan like a Sunon MF40202V2 or a Noctua NF-A9 FLX (with a 24V buck converter) provides significantly more airflow.

Pros: Takes 15 minutes, cheap, no printed parts required. Immediate improvement in airflow.

Cons: Still relies on the stock air intake and exhaust path, which may be restricted. Louder fan options may increase noise.

China-direct cost: 24V 80mm fan $3-6, buck converter $2-4 (if using 12V fan). Total: ~$5-10.

2. Ducted Intake System

A 3D-printed duct system that channels outside air directly to the critical hot spots: the stepper drivers (with heatsinks), the Raspberry Pi, and the controller board MCU. The duct mounts over the existing electronics bay fan and routes airflow precisely where it is needed.

Pros: Targeted cooling of the hottest components. Reduces driver temperature by 10-15C compared to a stock fan alone. Uses the same single fan.

Cons: Requires printed parts. Duct design must be matched to your specific electronics layout. Some designs block access to SD card slots and USB ports.

China-direct cost: Printed duct kit $8-12, stock fan (already owned). Total: ~$8-12.

3. Filtered Intake with HEPA / Carbon Pre-Filter

An intake system that filters outside air before it enters the electronics bay. This is particularly important for Voron owners who print in dusty environments or who use the electronics bay fan to push air into the chamber. The filter traps particulates that would otherwise accumulate on heatsinks and PCBs.

Pros: Keeps electronics clean, extends component lifespan, improves air quality in the chamber if the fan pushes into the enclosure. Customizable filter media.

Cons: Adds size to the electronics bay enclosure. Filter media needs periodic replacement ($2-5 per filter). Reduces airflow slightly compared to an open intake.

China-direct cost: Printed filter housing $6-10, HEPA filter media $2-4, pre-filter foam $1-3. Total: ~$9-17.

4. Dual Fan System with Temperature Control

The most comprehensive solution. Two fans: one intake fan pulling cool air from outside the enclosure, one exhaust fan pushing hot air out. Both fans are controlled by Klipper based on temperature sensor readings inside the electronics bay. This creates active, intelligent airflow that responds to real-time thermal conditions.

Pros: Best thermal performance. Electronics bay temperature stays within 5C of ambient even during 24-hour prints. Temperature-aware fan control means fans only run as fast as needed, which is quieter overall.

Cons: More wiring, more printed parts, requires a temperature sensor and Klipper configuration. Takes 3-4 hours to build and tune.

China-direct cost: Two 80mm 24V fans $6-12, temperature sensor (DS18B20) $1.50, printed fan mounts $10-15, wiring $3-5, optional fan controller board $5-8. Total: ~$25-42.

Parts List — Dual Temperature-Controlled Fan System

This is the recommended build for best-in-class electronics bay cooling.

Installation Steps — Dual Fan Temperature-Controlled System

Step 1: Print the Fan Mounts and Ducts

Download the STL files from the Voron User Mods repository. Search for "electronics bay dual fan" or "Voron electronics cooling duct." Look for a design that is compatible with your Voron model and electronics bay layout. The V2.4 300mm and 350mm have different interior dimensions. Print in ABS or ASA at 0.2mm layer height. Use 4 perimeters and 40% infill. The fan ducts should be solid to prevent air leaks.

Step 2: Mount the Intake Fan

The intake fan mounts on the side or bottom panel of the electronics bay, pulling cool air from outside the printer. Cut a hole in the panel if your design requires it, or use an existing vent. Mount the intake fan with the printed duct pointing toward the stepper driver heatsinks. Use M3x12mm screws and T-nuts if mounting to the frame.

Step 3: Mount the Exhaust Fan

The exhaust fan mounts on the opposite side of the electronics bay, creating cross-flow ventilation. Position it near the PSU and Raspberry Pi, as these generate the most heat. Ensure the exhaust fan blows hot air out of the electronics bay, not back into it. Do not route exhaust air into the print chamber — this would raise the chamber temperature and counteract the electronics cooling.

Step 4: Install the Temperature Sensor

Mount the DS18B20 temperature sensor in the center of the electronics bay, away from direct airflow from the intake fan. The sensor should measure the average ambient temperature. Wire the DS18B20 with a 4.7k Ohm pull-up resistor between the data line and 3.3V. Connect data to a free GPIO on the Raspberry Pi or controller board.

Step 5: Wire the Fans

Wire each fan to a PWM-capable fan header on your controller board. If your board does not have 24V fan headers, wire the fans directly to the 24V PSU output and use a MOSFET-controlled switch (e.g., Fysetc fan board or a simple N-channel MOSFET) for PWM control. The ground wires of both fans can share a common ground.

Klipper Configuration

[temperature_sensor electronics_bay]
sensor_type: DS18B20
sensor_pin: gpio17
min_temp: 0
max_temp: 100

[gcode_macro SET_ELECTRONICS_FAN_SPEED]
gcode:
  # {% raw %}
  {% set temp = printer["temperature_sensor electronics_bay"].temperature %}
  {% set speed = 0.3 %}
  {% if temp > 40 %}
    {% set speed = 0.5 %}
  {% endif %}
  {% if temp > 50 %}
    {% set speed = 0.75 %}
  {% endif %}
  {% if temp > 60 %}
    {% set speed = 1.0 %}
  {% endif %}
  SET_FAN_SPEED FAN=electronics_intake SPEED={speed}
  SET_FAN_SPEED FAN=electronics_exhaust SPEED={speed}
  }{% endraw %}

[fan electronics_intake]
pin: PD12
max_power: 1.0
shutdown_speed: 1.0
cycle_time: 0.010

[fan electronics_exhaust]
pin: PD13
max_power: 1.0
shutdown_speed: 1.0
cycle_time: 0.010

# Call the fan speed macro every 30 seconds during printing
[delayed_gcode fan_control_loop]
initial_duration: 10
gcode:
  SET_ELECTRONICS_FAN_SPEED
  UPDATE_DELAYED_GCODE ID=fan_control_loop DURATION=30

This configuration reads the DS18B20 temperature every 30 seconds and adjusts fan speed accordingly. Below 40C, both fans run at 30% speed (silent). Between 40C and 50C, fans increase to 50%. Between 50C and 60C, fans run at 75%. Above 60C, fans run at 100%. This keeps the electronics bay cool while minimizing noise when cooling demand is low.

Compatibility by Voron Model

Common Issues and Troubleshooting

• Fans too loud at high speed: High-static-pressure fans are inherently louder. Use PWM control with the temperature curve above to keep speeds low most of the time. Consider using 120mm fans at lower RPM for equivalent airflow with less noise. Add rubber fan mounts or silicone gaskets to reduce vibration transmission.
• Fan speed fluctuating constantly: If your DS18B20 temperature reading jumps by several degrees between cycles, the sensor may be too close to a heat source. Move it to a central location. Add a small heat sink compound or thermal pad between the sensor and the enclosure wall for more stable readings.
• Insufficient cooling with ducted system: Check for air leaks around the duct joints. Use foam tape or silicone sealant to seal gaps. Ensure the intake path is not restricted by cables or other components inside the electronics bay.
• PWM fan control not working: Some 24V fans have built-in electronics that do not respond well to PWM frequencies below 25kHz. Use a dedicated PWM fan controller board (like the Fysetc fan board) that generates the correct frequency. Alternatively, use voltage control instead of PWM by adjusting the fan voltage with a buck converter.
• Condensation on electronics: If you introduce cool outside air into a warm electronics bay rapidly, condensation can form on PCBs. This is rare at typical temperatures (20C delta), but if you live in a high-humidity environment, use a filtered intake with desiccant or gradually ramp up fan speed rather than running at 100% immediately.

Difficulty Level

Fan upgrade (stock replacement): Easy (1/5). Swap the existing fan, wire to the same header, done. About 30 minutes.

Ducted intake mod: Easy-Moderate (2/5). Print ducts, mount them, route airflow. About 1-2 hours.

Dual fan temperature-controlled system: Moderate (3/5). Requires printing, panel modification if needed, DS18B20 wiring, Klipper configuration, and tuning of the temperature curve. About 3-4 hours.

Proper electronics bay cooling is not an optional mod — it is a reliability requirement for any Voron that prints for extended periods or in warm environments. Even a simple fan upgrade to a higher-quality 24V fan provides meaningful improvement. For the best results, the dual fan temperature-controlled system with a DS18B20 sensor keeps every component in its safe operating range while remaining whisper-quiet when the printer is idle. Your stepper drivers, Raspberry Pi, and PSU will thank you with years of trouble-free service.