Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:2844928.
I had an ARRIS SURFboard SB6183 cable modem and it would constantly lose connection and require power cycling to fix. I took a Dremel tool to the case and put a small fan on it, and the problem was solved.
I upgraded to a SB8200 (AKA CM8200) and wanted a solution that looked a bit better, so I designed this thing to replace the side of the case and be able to mount a PC fan to the modem. Used M3x8 screws. This also fits the SB6121 and other modems with a similar design. It does not fit my original SB6183 (different shape and the heatsink is on the other side).
Took 12V power from the other side of the board.
6/21/18: Fixed an error with the feet, an edge that didn't line up properly, and added a 120mm version.
ARRIS SURFboard SB8200 DOCSIS 3.1 on Amazon (affiliate link)