This is a plastic shoe that you "Elmer's" glue to the bottom of the RoboNova-1 Robot feet to store LiPo batteries in the shoes for more and longer lasting power plus aiding to lower the c.g. for more stability.
The vertical spacing between the bottom of the cavity and the bottom of the RoboNova-1 is 6mm.
r2pv1.org/BigFoot.html
robotshop.ca/sfe-lipo-cell-3-7v-1100mah-3.html
Sorry Trossen (http://www.trossenrobotics.com/) you don't carry 1S1P LiPo's.
This is another of many entries to the makezine.com/go/makerbot contest ...
blog.makezine.com/archive/2010/04/makerbot_giveaway.html