Doctstar relies on natural convection for cooling. It has cooling vents on the sides and a "chimney" of vents at the top. Both it and the docked HDD can get quite warm if left running for a while.
I have designed a forced air cooling system. A small 40mm x7 cooling fan is used to draw exhaust air from 3 vents at the left, right and the chimney. The air exits at the back side of the HDD.
The air vent draws air from the front part of the case near the CPU and its DDR memory.
Here are the result after idling at 30.4C room temperature for 20 minutes.
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| Temperature is taken with an IR thermometer after running idle for 20 minutes at room temperature of 30.4C. |
The 3D printed design is made of 2 parts that can be glued together. The part holding the fan acts as a lid that is glued onto the vent. The 40mm x 7 fan is friction fit to the assembly. There are 2 flat surfaces - one along the top part of the cradle and one that make contacts with the top of the case. I used 3M VHB tape on them to attach the assembly to the Dockstar.
The 5V fan wires is routed through the air duct and spliced to the USB connector for power. I have also modified the case to bring out the 3V TTL serial port from the 2mm headers.
My USB HDD case is a bit smaller than the Seagate one. I have designed an insert for the cradle that sits next to the serial port. There is a slot that allows for reflection of the light from the HDD status LED.
