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Originally Posted by PAR_WIG1350
Acrylic should not be anywhere on your robot. Acrylic, aka plexiglass, is not impact resistant and is likely to shatter if used in FRC. I recommend using polycarbonate (aka lexan, makrolon, and a bunch of other brand names). This stuff is literally bullet proof.
That being said, Air is your friend, nearly All thermal insulation used on earth (space is another story) is air based. A small gap between your Jaguars and CIMS (0.5-2 inches) should be plenty to allow them to stay cool. leaving the area around them open will further decrease heat by allowing air to pass around the motors and Jags. This should be done regardless of the proximity of the jags to the CIMS whenever possible.
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We'd love to use polycarbonate. Unfortunately, our manufacturing capabilities are somewhat limited in regards to plastic. As such, we're going to laser-cut several parts out of acrylic at a local machine shop, but they don't allow polycarbonate (pesky toxic fumes.) Hence the acrylic. We're limiting it to only parts that will experience very little load, and we'll fasten very, very securely, as well as coming with several spares and reinforcing key points. If anyone's willing to run polycarb or aluminum routing for us, let me know, but we really just don't have the resources. We're also using acrylic plus, which is considerably more impact resistant.
Awesome, thanks. One of our design goals this year was to keep the CIMs clear. We've got plenty of free space in front and behind them, and we're venting the space below them, too. I'll lobby to throw in fans, and we should be in business.
Quote:
Originally Posted by Chris86
I personally don't believe that the CIMs would get quite that hot. Even with heavy driving, we've only ever gotten the CIMs to barely being warm, and never so hot that you can't grab onto one without injury (with everything powered off of course)
Over a two-minute match, I wouldnt believe that this could be a problem, but somebody else may have had different experience with overheating CIMs?
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That's pretty lucky. Ours, and many other teams, have gotten very hot. You could burn yourselves on them. Watch out for it.
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Originally Posted by slijin
I can't speak for CIMs overheating, but the Jaguar spec sheet indicates that the operational range is -40 to 85 deg C. |
Shouldn't be too hard to keep them within that range. Thanks!
Quote:
Originally Posted by Keyreaper
In our team's experience, under continual use CIM Motors can get very hot. Hot enough to practically fry an egg on. This would often happen when were trying out drive team, practicing, or in the final paces of a tournament. The acrylic I would believe would dissipate the radiating heat somewhere else, but as far as I know only the CIMs get hot, they don't actually radiate heat like a heatsink for a CPU.
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Sounds like our experience. We mounted fans on our cart in order to cool down between matches. Glad to hear that they shouldn't radiate too much.