Minisforum BD770/BD790i 140mm Fan Mount

I wanted to mount a 140mm fan to my BD770i for additional air flow. However, the included bracket only allows for mounting of a 120mm fan. 

This mount allows a 140mm fan to be mounted offset to the I/O shield and bolts into the existing 120mm bracket to secure each side. 

Onshape Link

Bill of Materials

You'll need:

• 4x M2.5 4-6mm screws
  • Used to screw these into the existing 120mm fan bracket.
  • You can use either 4mm or 6mm screws, but 6mm is likely the longest it can go. 
  • It's recommended to use one with a smaller head such as a narrow pan head. Larger heads like full sockets may collide with your fan blades depending on how much clearance there is. Traditionally, you shouldn't have an issue, but better to use smaller screws if available
• 4x M4 [15/20/30/35]mm screws 
  • Length of screw depends on your fan thickness. Add 5mm to whatever thickness your fan is
    • i.e., if you are using a 20mm fan, go with a 25mm screw
  • Can be any kind of head you choose, as long as your case has clearance for the fan+head.
• 4x M4 4mm Heat Set Inserts (Optional)
  • Two versions of the files are provided: (i) heat-set inserts for M4 4mm (5.5mm diameter) inserts; (ii) threading directly into plastic
  • If you are planning on redoing the fans often (and unscrewing frequently), you should use the threaded insert version.

Installation Instructions

• Install the included fan bracket with the BD770i/BD790i motherboard
  • There are two metal brackets included with the motherboard that are black and have two small posts each. Those should get screwed onto your motherboard cooler using the included tiny Phillips heads. This would be done regardless of using this mount and the traditional 120mm fan mount.
• Install the THINNER piece
  • Install the thinner/smaller piece on the bracket that is closer to the I/O shield. This is required as a center 140mm fan will not actually fit with the I/O shield, so it needs to be offset. This should be parallel to the I/O shield
  • Push the bracket into the posts. There are two smaller holes that correspond to the 120mm posts. If it doesn't fit, flip the bracket over…
• Install the LARGER piece on the other bracket