My right extruder fan started acting like a jet engine-- spinning up slow and making a whole lot of noise. I decided to upgrade to a set of ball bearing fans.
I also like Wingcommander's retaining pin, but they weren't quite the right size for this setup, so I shortened the length of the pin and rounded the cap a little. These pins hold the fan guard in place at the top of the fan where normally the holes are left empty.
Orion brand fans have a good reputation on the [Makerbot Operators Group](https://groups.google.com/forum/?fromgroups=#!forum/makerbot) so I went with those.
This thing is really more of a list of part numbers for the fans and connectors so that people have a quick place to refer when ordering. All this info can be found in the [Makerbot Operators Group](https://groups.google.com/forum/?fromgroups=#!forum/makerbot) but you have to search for it in various posts.
I choose the 7CFM fan. I think even the 6CFM fan would put out more air flow than the stock fans. The stock FSY40S24M puts out 5.75CFM.
- 1053-1208-ND FAN DC 40X10.5MM 24V 7CFM - The fan, you want 2
- 455-2266-ND CONN HOUSING 2.5MM 2POS - The connector, they're cheap, might as well get 10
- 455-2261-1-ND CONN TERM CRIMP XH 26-30AWG - might as well get 20 or more so when you screw up one you have more to try again.