pic: Our best 2011 robot design

[Ian Curtis]

1276 built a similar hinged mast in our 2007 robot.

That joint needs to be beefy. As you can see we had a circular mast, and welded on square tubing which is where the joint actuated. There were also a set of guides inside the mast that helped guide it down.

It worked, but not nearly well enough. Our piano hinge was purchased at a hardware store, and was not up the rigors of competition. I don't remember the diameter of the pin in the hinge, but it was somewhere around 1/8" and the hinge ran the entire length of box tubing. We actuated it on Thursday (it was pushed up by the elevator), but ultimately we were not comfortable with leaving it that way during matches, so we bolted it upright and were a 6' tall robot (which was legal in 2007). As others have mentioned, you get quite a lot of torsion (twisting) and some pretty sever shockloads when it slams down if you are not careful. Also give some consideration on how it will be held in place once it actuates up... don't want it coming down mid match!

McMaster sells much beefier piano hinges than what we used, I would recommend using them. Go as thick as you can without paying out the nose.