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Unread 03-02-2014, 19:13
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DampRobot DampRobot is offline
Physics Major
AKA: Roger Romani
FRC #0100 (The Wildhats) and FRC#971 (Spartan Robotics)
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Re: pic: 2471's final winch assembly gear side

Quote:
Originally Posted by Bryce2471 View Post
Thanks. We haven't done any testing of the torque output yet. But the numbers say that it will be more than enough power.
The 18 volt 775 stalls at 166oz-in of torque or 10.3lb-in. After a 71:1 gear reduction that's 735lb-in. Our spool only has a 0.625" radius, so under perfect conditions it should stall producing 1180lbs of force. Multiply this by a rough torque efficiency of 0.75 and you get 880lbs.

Our shooter should take less than 200lbs to retract so the motor will be running in its happy place (about 10,000rpm) which should pull our cable at about 10in/sec. So it should get the job done in a little over 1 second. Of course it's all theoretical at this point.
Interesting. Our 2 CIM worm gearbox with about an 80:1 final reduction with a 1" diameter pulley takes about 3 seconds to pull back our 130 lb shooter. I'd be interested in hearing your results when you test it on the robot.
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