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Unread 13-09-2014, 21:54
Joe G.'s Avatar
Joe G. Joe G. is offline
Taking a few years (mostly) off
AKA: Josepher
no team (Formerly 1687, 5400)
Team Role: Mentor
 
Join Date: Sep 2006
Rookie Year: 2007
Location: Worcester, MA
Posts: 1,449
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Re: Experience With 6 Cim Drive train

1687 ran 6 CIMs single speed last year, at 14.5 fps, riding on colsons with a linear tread pattern, playing some real tough defense all year long. At our first event, we tripped the breaker once in our final match, at our second, a couple more times. After that, we looked for ways to eliminate breaker trips for our offseason events. Retrofit shifters were designed, but for various reasons, couldn't be manufactured in time. Instead, we made several minor mechanical, electrical, and software tweaks to reduce current draw:
  • Doubled the number of air tanks on the robot, reducing required compressor runtime
  • Systematically tested every pressure switch we own to find the one with the best combination of high cutoff pressure and low startup pressure, again reducing required compresser runtime
  • Switched our intake extension, our largest source of air use, to single acting pistons
  • Upped wire gauge in several places in the robot, reducing losses due to wire resistance
  • Coded our drivetrain to automatically drop to 4 CIMs when running our shooter winch or intake motors, with the driver given a trigger to override this in high-pressure situations
  • Added a trigger for our driver to shut off the compressor regardless of pressure during pushing matches
  • Added ramping to drivetrain which limited sudden accelerations and abrupt direction changes slightly

Did not trip the breaker after this. However, we do plan to use shifters in the future, or gear lower if the game does not call for the speeds we geared for this season.
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FIRST is not about doing what you can with what you know. It is about doing what you thought impossible, with what you were inspired to become.

2007-2010: Student, FRC 1687, Highlander Robotics
2012-2014: Technical Mentor, FRC 1687, Highlander Robotics
2015-2016: Lead Mentor, FRC 5400, Team WARP
2016-???: Volunteer and freelance mentor-for-hire