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Unread 03-07-2008, 19:17
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Billfred Billfred is offline
...and you can't! teach! that!
FRC #5402 (Iron Kings); no team (AndyMark)
Team Role: Mentor
 
Join Date: Feb 2004
Rookie Year: 2004
Location: The Land of the Kokomese, IN
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Re: 6WD Chassis Stiffness vs. Maneuverability

In 2006, when I was still with 1293, we used the kitbot--stock ratios and all--feeding one IFI wheel in the center and Skyways on the corners. The videos I've seen all show us whipping around pretty hard, and we were quick enough to do our job (defense) effectively. It didn't get us into eliminations, but it was good enough to be the best finish the team has ever achieved in qualification rounds (before or since).

In 2007, I took the concept with me to 1618. This time, we used skinned-and-roughtopped AndyMark FIRST wheels, driven by a Gen2 AM Shifter using the big and small CIMs. We used the second speed to blitz across the field, important when stopping folks on the far side of the rack. Observation from off-season testing and Brunswick Eruption showed that this design was a little harder to turn. It doesn't like to turn in place, though it'll do it when you push it hard enough (as I found when one of the pre-rookies on 2458 about spun the numbers off of it at Brunswick Eruption).

This year, we switched to the AM Super Shifter with two CIMs per side for lack of the large CIMs. (And, truthfully, we would only have used other motors on drive if we really needed a CIM elsewhere.) Instead of roughtop, we used wedgetop cut with the long diamonds going around the wheel (as opposed to how IFI cuts theirs) for a little less CoF since we were flirting with the upper limits of current draw if we stalled a motor. (That was before we never got to a manipulator and weighed in south of 75 pounds.)

The more revolutionary change for us was riveting the frame together instead of using bolts. The result was the tightest frame I've ever had a hand in (well, excluding Bob in 2004 where we sent out the 2x4 aluminum of that year's kit to get welded together). The weight was slightly skewed towards the rear, with virtually nothing more than a foot off the ground. When driving both, I've found Speedy Debris to be a little easier to turn than Uppercut before it, though it may be a function of the 30-pound weight difference. An apples-to-apples comparison of bolted frames against riveted frames would be interesting.
__________________
William "Billfred" Leverette - Gamecock/Jessica Boucher victim/Marketing & Sales Specialist at AndyMark

2004-2006: FRC 1293 (D5 Robotics) - Student, Mentor, Coach
2007-2009: FRC 1618 (Capital Robotics) - Mentor, Coach
2009-2013: FRC 2815 (Los Pollos Locos) - Mentor, Coach - Palmetto '09, Peachtree '11, Palmetto '11, Palmetto '12
2010: FRC 1398 (Keenan Robo-Raiders) - Mentor - Palmetto '10
2014-2016: FRC 4901 (Garnet Squadron) - Co-Founder and Head Bot Coach - Orlando '14, SCRIW '16
2017-: FRC 5402 (Iron Kings) - Mentor

94 events (more than will fit in a ChiefDelphi signature), 14 seasons, over 61,000 miles, and still on a mission from Bob.

Rule #1: Do not die. Rule #2: Be respectful. Rule #3: Be safe. Rule #4: Follow the handbook.