Base support for original EEZYbotARM

Having built daGHIZmo's original EEZYbotARM (http://www.thingiverse.com/thing:1015238) I found that (at least for my build) the rotating platform and "basement" had too much clearance. While this was not meant to lift a lot of weight, the wobbly nature made the end effector's positioning a bit unreliable. Having already made the compete unit, I thought about redesigning the basement part but then realized a quicker and simpler solution. That solution is this part. It just slips over the basement part and creates a more stable interface. To reduce friction, I smooth sanded the top surface and applied a bit of synthetic grease (like the kind used for spark plug boots on a car).