The manual says that fans that are “part of a legal COTS computing device” are allowed. We’re using a raspberry pi for vision processing, and we’ve had problems with it overheating in the past, so we have a heatsink along with a fan that we took off of an old Talon SR, powered off the VRM. The Raspberry Pi didn’t come with the fan, so does that make it illegal? And if so how else would we cool the raspberry pi?
If the Raspberry Pi didn’t come with the fan, I wouldn’t say it’s part of the COTS computing device. However, you ARE allowed to use other fans as long as that they were offered in the KoP or FIRST Choice (not just this years’ selections, but all past years as well). There have definitely been some bigger fans (80 or 120mm?) that were legal in the past.
Additionally, you are allowed to use fans that are part of a legal motor controller, which makes it sound like you would be allowed to take the fan off a Victor and use it on the Raspberry Pi, but that’s a bit of a gray area, I would ask an inspector about that first.
Other relevant rules, R34 allows you to power the fan without a motor controller (by plugging it in directly to the PDP), and R56 says you are allowed an unlimited amount of legal fans on a single 20A breaker.
You said that you can power a fan off of the PDP, but we currently have a fan from a victor that is plugged into the VRM. Would this count as a 20 Amp breaker because the VRM is connected to the 20 Amp fuse from the PDP?
That will work too.
We got two 120mm fans and two 10 or 20?mm fans, this year. I don’t remember if they were in the K.O.P., or First Choice. AndyMark lists a 10mm fan.
Yep the 120mm ebmpapst fans are the only legal “big” fan. Still has a decent CFM, Delta Server fans are the most powerful available in 120mm( I bought a 50watt 120mm for $12 from Aliexpress a while back) not legal though.
A little motor controller fan will easily keep a raspberry Pi cool. You could also add a heatsink to it with thermal paste. If you are using a case, it will run hotter in a case.
Is there a list somewhere of all the fans that were previously provided in the KOP or other FIRST related sources?
My team also has interest in a small (Victor size) fan to cool a co-processor.
Very much want to avoid using an ESC for a simple fan.
On the first part, a fan that is part of a legal motor controller is only legal when it is on that controller. However, the allowed motor list includes this…
Hard drive motors or fans that are:** included in any Kickoff Kit, distributed via FIRST Choice**, part of a legal motor controller (including manufacturer provided accessories), or part of a legal COTS computing device.
Emphasis mine.