Introduction: Thermal Control for VR Headsets With Fan
Using a Fan to increase the airflow will improve the performance of the passive heatsink for VR headsets described in this instructable: https://www.instructables.com/Thermal-Control-for-VR-Headsets/
Just add cooling fins, and a fan.
Sheet aluminium, 250 mm wide.
Thermal pads, for example "Thermopad Thermal Grizzly Minus Pad 8- Silikon", or "Thermal Pad, Tflex 300 Series" (Grizzly has better specs.).
Tools for cutting, and bending aluminium.
Pen, ruler, and a sharp knife.
The extra needed for the Fan:
Raspberry Pi 4 Quiet Fan 30x30x7mm 3007 Fan DC 5V 3.3V
MP1584EN step down converter – 4.5–28 v to 0.8–20 v Arduino
Battery, battery connector, and cables.
Tape, and a piece of Cardboard paper of similar thickness as the aluminium, for the template.
Tools for connecting, and soldering wires, and a voltmeter.
Step 1: Make a Template
Make a template of cardboard that fits the phone. The heatsink should cover the whole back side of the phone.
Mark, and cut out the fins, and figure out how they should be bent to catch the air flow from the fan.
Test the template in the headset. Use tape to temporarily hold the fan, and the flimsy paper in place.
Step 2: Transfer the Template, and Cut
Transfer the template to the sheet, and cut the aluminium.
Avoid bending the sheet in the areas that will make contact to the phone.
I used a hacksaw for the long cut, and a miniature rotating saw for the opening for the camera.
The fins was cut out using sheet metal scissors.
Use a file to make the cuts, and the corners nice, and even.
Step 3: Bend the Fins
Bend the fins using pliers, and hammer to make them nice and sharp.
Each fin are bended in two directions, first a diagonal bend ca 45-90 degrees down, and then a straight bend up.
Step 4: Mount the Fan
Check the direction of the airflow of the fan, and mount some screws (mine was included with the fan).
Mount it by tangle in the screws to the fins. Fine adjust by bending the fins for holding the fan, and to smoothly catch the air flow.
Fixate the fan with a rubber band. Make sure the rubber band, nor the fins will touch the fan blades preventing them from spinning.
Step 5: Add Battery Connector, and Fan Speed Control
Solder the wires from the battery connector, and the fan to the rpm controller.
As the fan runs on 3-5 V, and I was using a 9 V battery, the rpm control is done with a step down bucket voltage converter. Use a volt meter to make sure the fan isn't feed with higher voltage than its built for, and adjust the speed to a comfortable level.
If the battery voltage matches the fan, a pwm controller might be an even better choice.
Step 6: Add the Thermal Pad
Add the thermal pad to the heatsink, and cut it to the same size as the phone.
Step 7: DONE!
Put it all together. Place the heatsink on the phone, and then in the VR headset. Connect the battery connector to the battery to start the fan.
Tip. Keep the protective plastic film, and put it back to protect the pads from dust when the heatsink is not used.