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Unread 10-11-2015, 13:35
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Travis Covington Travis Covington is offline
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FRC #0254
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Re: pic: ABS-110, lightweight 2-speed PTO gearbox

Quote:
Originally Posted by Chris is me View Post
In the case of both 254's and 1114's 2010 robots, the PTO did disengage the wheels. With 254 this is evident when you watch the robot extend its arm - it has to stop driving to unfold the hanging arm. I don't know where you're getting this information from. There are serious risks to trying to align something when the PTO is moving you away from your target. You almost never want your wheels engaged while your PTO is doing something else.

In 2013, if 254's PTO didn't disengage its wheels, that's just because the wheels had already left the ground at that point, so the feature wasn't necessary. This is unique to the 2013 hanging task.
This is correct. In 2010 we disengaged and in 2013 we did not. In 2013 the drive wheels were already off the ground so we had no need for the three position cylinder. When we were hanging, the drive wheels were also spinning back and forth. No big deal.

Be careful with the three position cylinders though. They do not behave exactly the same as two 2-position cylinders stacked back to back. See this post here for details: http://www.chiefdelphi.com/forums/sh...75#post1276175
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-Travis Covington

2008-2017 - Engineering Mentor of Team 254
2001-2008 - Engineering Mentor of Team 968
1998-2001 - Mechanical Director/Driver/Member of Team 115
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