Thread: Arms
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Unread 08-04-2007, 10:57
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Billfred Billfred is offline
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FRC #5402 (Iron Kings); no team (AndyMark)
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Re: Arms

In four years of FRC, I've had a hand in three arms.

1293 in 2004: 1x1 box tubing mast (only up to the 5' mark), structure for grabbing the 2X ball from angle aluminum as I recall, homebrew linear bearings, winched up and down by a steel cable driven by a van door motor. Winched fine, just not effective at its task. Ditched Saturday at Palmetto.

1293 in 2005: 1293 gets up close and personal with the joys of 80/20. Three-stage lift, driven by timing belts and a van door motor. Worked beautifully, but hampered with drive issues (namely an inability to get it pointed the right way for most of the Palmetto Regional). The only real problem was that we'd frequently trip breakers on the van door motor, but only when stalled for a significant amount of time. Much of the lift design (and some components, as 80/20 linear bearings aren't particularly cheap) was recycled for their 2007 robot, Atlas.

1618 in 2007: Nobody on the team had ever done a jointed arm before, but it was the cheapest way we could figure out. A small CIM and a BaneBots handled the first stage of 1.25" PVC pipe, while the second stage was a Denso motor. Eventually, the second stage was turned into part of a gripper, and temporarily changed over to a Keyang motor before going back for mounting reasons. (There are plenty of pictures on CD-Media of the pre-gripper setup, and a couple of the later setup.) The arm never fully functioned in competition, but appears to be easily fixed once 1618 returns to work after their spring break. (Victors, lemme tell you...)

Of the three, my favorite remains 1293's arm in 2005--I'd reuse that design again in a heartbeat, resources permitting. But if you're on a budget, you can't beat the PVC arm.
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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.