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Unread 12-12-2012, 02:31
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Tristan Lall Tristan Lall is offline
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FRC #0188 (Woburn Robotics)
 
Join Date: Aug 2001
Rookie Year: 1999
Location: Toronto, ON
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Re: 3-motor transmissions

188 had this capability in:
  • 2002: Old Bosch Drill, Johnson F-P & Old CIM (single-speed)
  • 2003: Bosch/Scintilla Drill, Mabuchi F-P & CIM (single-speed; never did get the radial-engagement shifter to stay engaged)
  • 2004: Bosch/Scintilla Drill, Mabuchi F-P & CIM (two-speed pneumatic dog clutch)
  • 2006: gearbox was designed to be adaptable for combinations of up to 5 motors (F-P with planetary, big CIM, 2 small CIM, and even a Globe if you really wanted to), but only built with 2 small CIM (three-speed servo-shifted DeWalt XRP1; in retrospect, the shifter was pointless for that game, and the servo too slow to actuate the mechanism)
(I have to admit it's been a few years since I dealt with these robots, so where this differs from previous information, assume this list is inaccurate.)

1 That was a crazy design that combined all these motors into a single XRP gearbox—which actually worked surprisingly well, apart from the manufacturing errors, and the tendency to break shafts. (The interface shaft between the XRP gearbox and the motor gearbox was too difficult to make on our lathes as a single piece of steel; it had a joint that wasn't initially robust enough. Also, the output shaft was AISI 12L14, replacing the hardened steel output shaft that comes with the DeWalt gearbox; we found out that after about an hour of running, they would fail in a ductile manner, in torsion. We should have picked a better material, preferably something easily hardenable like AISI O1.)
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