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Unread 02-02-2009, 22:32
Greg Peshek Greg Peshek is offline
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Join Date: Feb 2006
Rookie Year: 2011
Location: Seattle
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Re: Team 665 Fan/s and More

Quote:
Originally Posted by Tom Line View Post
Like I said - 320 pounds if uniform. Assume it's not, so I halved the value to 150. Even if you want to cut it 80%, they're going to get similar drive from that fan as they do from the wheels, so they'll accelerate twice as fast as a non-ducted bot.

They better not have the air-intake on the bottom of the robot though.....
During the video I posted, you can see our mentor measuring the wind speed at different locations around the blade. It is roughly 26 mph at the far tips of the blade and 28 mph toward the middle of the blades. Don't worry, the air-intake on the bottom was our original plan until we pulled up our test flooring on the third day. Then we saw the update and that was categorically disqualified.

Quote:
At some point you have to start wondering what all the backwash from your props will do to the other robots on the field, including your own partners. We'll find out in Orlando I suppose
There's a big volume of air being pushed out, if you watch the video closely, you can see the papers blowing 20' away from the prop, but we are fairly sure by the time the backwash diffuses after being pushed out the fan there shouldn't be any giant surfaces for the air to catch on with the other robots. Let's just hope no one puts sails on their robot.

For anyone interested, we measured the amp draw at different power outputs.. it's about 20 amps on startup, 8-10 amps on 50%-75% speed, and 4 amps at 100% throttle.

As far as the safety aspect, the metal for the cowling is only 1/32", so it was fairly easy to bend and make into a circle. Although we are confident that if the blade is to come off and shatter, the cowling would stop or drastically reduce the velocity of any dangerous debris. Since there really isn't any scale, the mesh we have protects against putting fingers in. One girl on our team can fit her pinkie finger in the mesh, but even then it wouldn't be long enough to get to the blade. So we figure a 10 year old won't be able to hurt themselves even if they tried.

Thanks for all of the comments and input guys.

-Greg