Friday, December 21, 2007

More track

Rolling ball sculpture has a couple different major sections to it's construction. First the frame, then the lift, then track and elements. The frame is straightforward, and should be braced before you begin building, so that the frame will not move. It does not seem too important when the frame has no track on it, but when the marbles start to roll, they exert energy and can make the whole sculpture shake.

The lift is somewhat complicated, but I think the real challenge with the motor is installing it so that the weight of the lift is off of the motor shaft - more of a concern with a helical lift than a chain lift.

Finally there are track and elements. I have somewhat explained making track in my how to secion on my website, but I have a little more to say here. I am working on a table top sculpture that has three tracks. One track for the loop d' loop, one track with just one marble that goes slow and has a few tipping arms. The third track will have a marble collector (adjustable) that will tip with 3-6 marbles, you choose. Track seems like it is the easy part of making RBS. Actually, it can be quite frustrating to make a track that just doesn't seem to fit into the space you have for it. I have found recently that the best way to add track that fits perfect the first time is to bend as much, if not all, of the wire track after it has been attached to the previous section. Track is not just for the ball to get from one place to another, but can be an element in itself. It is very important to keep the spacing consistent and to test the marbles as you go so you will not be surprised later, and not be able to get to the spot to fix it because it is buried behind other things on your sculpture.

I think making track is a lot like drawing a maze. Sometimes the track path must be very carefully led out of a tight spot. If you are truly stuck, the use a tipping arm to lower the ball down. Get creative! Since everything you will make is one-of-a-kind then your imagination is your only limit (besides tooling....).

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