pic: 775 cooler

a simple 775 cooler and that’s it so… here you go

Is the fan pushing air onto the motor or pulling air out? It seems like this would block the air vents and do more harm than good.

its pushing

look at this picture and it will probably make more sense

Ahh, that makes infinitely more sense. Looks great!

Have you done any temperature measurements under load to see if the additional airflow is effective?

Seems to me like a mild static pressure increase without a significant cfm increase might not be the best way to attack cooling.

…Which now has me designing an impeller design that might do decently as well.

light testing showed some improvement in temperature while the motor was under load although not efficient in any way it showed some improvement, but i mean something is better than nothing without effecting throughput. Definitely couldn’t hurt.

Doesn’t the impeller in the 775 draw air in through the slots in the end by the output shaft and exhaust it through the slots at the end near the terminals? Blowing air into the exhaust ports could mess up the internal air flow.

Where are you measuring the temperature? Please remember that it is the rotor that is generating the heat, not the case.

Unless that fan is from the kickoff kit, I’m fairly certain this isn’t legal per R32, in case anyone is planning to use it in competition.

Plenty of similarly-sized fans were available from FIRST choice as well. It’d be trivial to swap in a similar fan if this one wasn’t explicitly from the KOP or FIRST choice.

Rule is any kickoff kit. Muffin fans of various sizes were common in said kickoff kits for quite a few years, back in the mid-2000s or so. (Not that terribly many were actually used…). The OP team is certainly old enough to have a few of those, and I want to say that that one looks familiar. Maybe around the 2000 vintage? I remember 'em being a bit thicker when I was a student.

Seems like it is designed for a 40mm fan, the same size used on Talon SR’s. 888’s and 884’s use a slightly thicker 40mm fan( not sure which style would be better for this). Either way KOP supplied 40mm fans are plentiful for teams who have been around a while.