We happened to have the case on an arm that is long enough to clear the brick and pass that vertical plane. If your kids can't tweak the arm so it leans back, there are 2 other approaches that come to mind.
You could branch the program to slowly lift the cast as you approach the bone, and then when in place, lower the cast (the timing on the slow raise would be a proxy for a brake.)

Or you could create a tension system via bands or gears & chain that holds the cast up until the motor lowers it. (I don't know how I'd ask guiding questions to point my 10 year olds in that direction, but luckily didn't need to.)

Good luck.

Tom
The Blockheads
Team 2280
-----Original Message-----
From: Frank Fenneran - Team #53 Brainstorms [mailto:[log in to unmask]]
Sent: Wednesday, October 27, 2010 10:23 AM
To: [log in to unmask]
Subject: Re: [VADCFLL-L] Common Bone Repair

We find this to be an issue almost every year (the kids love to carry stuff around in "boxes" instead of pushing). The only solution we've ever found is to get the item beyond the vertical plane so it sits back toward the body of the robot while moving, then bring it back around to the front to place it down. The motors don't have a "parking brake" :) -Frank -----Original Message----- From: First Lego League in Virginia and DC [mailto:[log in to unmask]] On Behalf Of Kevin Weaver Sent: Wednesday, October 27, 2010 10:02 AM To: [log in to unmask] Subject: [VADCFLL-L] Common Bone Repair We are working on the putting the cast on the bone, but the cast is to heavy for our motor. Is the a way to code the motor to hold the brake until we want it to turn and put the object down? -- To UNSUBSCRIBE or CHANGE your settings, please visit https://listserv.jmu.edu/archives/vadcfll-l.html and select "Join or leave the list". -- VADCFLL administrative announcements are sent via VADCFLL-ADMIN-L. Visit https://listserv.jmu.edu/archives/vadcfll-admin-l.html to subscribe. -- To UNSUBSCRIBE or CHANGE your settings, please visit https://listserv.jmu.edu/archives/vadcfll-l.html and select "Join or leave the list". -- VADCFLL administrative announcements are sent via VADCFLL-ADMIN-L. Visit https://listserv.jmu.edu/archives/vadcfll-admin-l.html to subscribe. 

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