Mikrotik CRS309 Fan cover

I designed this Cover and Fan support for cooling the SFP+ RJ45 modules in my Mikrotik CRS309 (fantastic router/switch). With this, my modules seem to be running very cool: in fact when touching them I feel they are not even slightly warm.

I use the logo as additional air exhaust.

Print:

• PLA: if your fan is efficient, the board remains at 25C, no need for PETG or ASA
• Use the 3mf files with the dovetail cuts, or alternatively, cut the STL as you like.

Fan:

• I use an old Noctua NF-S12B ULN, with slightly less than 60m3/h, it's silent and efficient enough. It runs at less than 0.5 W
• I first tried with a Noctua Redux 1700, that was noisy and completely overkill. It runs at about 1 W

Details: 10 Gbps SFP modules are typically used in routers/switches for connecting CAT6a up to CAT8 ethernet cables running long distances (30m - 100m). Problem: the SFP modules run quite hot (80-90C is quite common) if not cooled. DAC are the best alternative for short distances (better latency than fiber), fiber are great for long distances if you're lucky enough to have these running where you need. In typical home setups, you have ethernet. Good CAT6a CAT7 is cheap, reliable, does not break when installed, and can be cut to the right length.