CR-10 Control Box Cooling Mod

thingiverse

The CR-10 printer boasts an impressive array of features, but its control box falls short due to the conflicting efforts of three internal fans that work in tandem to create a hot and noisy environment. Frustrated by this design flaw, I decided to take matters into my own hands and modify the system. My primary goal was to eliminate the two fans within the box and reposition the single fan in the power supply unit to direct airflow inward. To achieve this, I removed the back top and front of the control box, fabricated a duct for the front, and installed a fan at the rear. Ideally, the larger fan would draw air through the power supply and exhaust it out the back top via the front air duct. In practice, the upgrade performed exactly as intended, with the PSU fan serving as a backup that only kicks in when the power supply reaches high temperatures. Since upgrading, I've logged approximately 20 hours of printing time without the power supply fan activating, thanks to the larger fan's effective airflow management. The sole components needed for this modification are the front air duct and a replacement piece designed to fit where the small fan was originally situated on the back of the control box. To avoid compromising the structural integrity of the system, I opted not to simply tape or paint over the old fan holes. The rear knockout hole was created using a 4-inch punch, resulting in a clean cut compared to the front holes, which were produced with a 1-inch punch and later expanded using tin snips found in the trash. Although the snips were less effective than anticipated, the front hole still requires some adjustments to accommodate the air duct's larger border. Following this process, I filed down the sharp edges, drilled, and tapped holes for the back fan, repainted the area, and began printing the necessary duct and cover components. Once complete, I installed the fan, secured the duct in place with adhesive, and reassembled the system. To date, the upgrade has significantly improved cooling performance, with the power supply fan only activating as needed. The primary fan is now much quieter than its predecessor, and the sole remaining noise comes from the stepping motor's whine. However, I did encounter one issue: the contact on the bed heater MOSFET melted due to a loose screw, which forced me to disassemble the box once again. Upon re-examining the MOSFET board, I discovered that only the terminal block had sustained damage. To avoid risking further harm to the bed or rewiring the MOSFET board, I elected to replace it with a BIQU Heat Bed Power Module Expansion Hot Bed MOS Tube from Amazon. Although this upgrade offers several benefits, including higher current handling and support for 24-volt operation, its massive size and heat sink preclude it from being installed in the original location. Instead, I found an alternative spot above the power supply on the side of the control box that can accommodate the new board. To secure it in place, I drilled additional holes and employed extra plastic circuit board clips. I also rewired the bed connector and thermocouple to increase the wire gauge. The result is a well-cooled FET heat sink positioned below the large fan, which boasts ample airflow and efficient cooling performance. Notably, the upgraded system now heats up faster than before, and the power supply fan remains dormant due to the effective airflow management provided by the larger fan. I'm thrilled with the outcome and am eager to assist others in eliminating excess heat and noise from their control boxes.