If you wanted to build the Marblevator "Mini" series but hesitated because you didn't want to buy motors, connectors, power supplies, batteries, etc., and then have to solder the whole mess together, then this thing may be for you. This is a counter clockwise hand cranked base designed to work with the three Marblevator "Mini" tracks; Bowl, Seesaw and Zigzag (for a clockwise cranked version, see this thing: http://www.thingiverse.com/thing:313944). The photo is shown with the Marblevator "Mini", Zigzag track, but the video that follows shows all three tracks. Caveats: it does require finesse in building and a very steady hand in operating, but if I can do it, so can you as shown in this video https://www.youtube.com/watch?v=ZIS4EiZXx2s. Printed in PLA on a Makerbot Replicator 2 using Makerware 2.3.3.42 "Standard" settings.Study "Assembly.skp". Print all parts. After printing "Base.stl" break off the four hold down disks at the corners and trim, file and/or sand smooth (the hold down disks help minimize warping during printing). Press "Knob Crank.stl" into the square hole in "Crank.stl". A small dot of thick cyanoacrylate is a good idea to keep the knob assembly attached to the crank. Lubricate the holes that guide the crank shaft with white lithium grease. Slide the crank assembly part way into "Base.stl", then slip "Collar.stl" onto "Crank.stl". Lubricate "Gear Crank.stl" with white lithium grease then place it into position, the press "Crank.stl" into "Gear Crank.stl". At this point, make sure the hand crank operates smoothly. If it is tight, slightly enlarge the two holes that the crank shaft passes through by filing, sanding, trimming, or using a 15/64" drill bit, then re-lubricate. Lubricate "Gear Crown.stl" with white lithium grease then place it into position. Slide "Collar.stl" towards the hand crank to hold the hand crank in position. This may require a number of adjustments until the hand crank and crown gear operate smoothly. When you are sure of the final position of the collar, apply a small dot of thick cyanoacrylate to the outside edge to hold it in position. Install the track and press in the worm gear. Break in the assembly be rotating the crank counter clockwise as viewed from the knob. Manual Marblevators Unite and Marblevate!