How do I manipulate a large number of moving platforms?

How do I manipulate a large number of moving platforms?

• I might not be in the best place to ask this and feel free to tell me to move my question to another Stack Exchange. I am trying to build a device that will allow me to control at least a couple hundred raising platforms. The goal of this is to create a real time editor for board games (more precisely Dungeons and Dragons). Ideally all the platforms would move simultaneously and the platforms would be transparent to allow us to place L.E.D.'s inside them to color the platform (this way we can make wood brown, water blue etc). On our current setup, we would use acrylic prism 1 inch x 1 inch x 6 inch (width, length, height) and we wanted to use a CNC motor to move around on a X/Y axis and change the platforms elevations. Obviously, this is NOT simultaneous raising at all and had (on paper) quite a long update time (calculated approximately 1 sec per platform). CNC is the only solution we found that had a reasonable cost/quality (a CNC motor per platform also raised the power consumption very high).After a few weeks of looking around, planning and throwing stupid ideas away, we found http://www.youtube.com/watch?v=lvtfD_rJ2hE. Clearly, WAY better then our idea but I have no idea how he did this. They have 900 and they all work simultaneously; his platforms are much smaller too which could be nice to have but 1 inch ^2 is fine for our use. We also don't want the real time interactive thing. Loading from computer and staying static until we change it is good (though water movement would be really nice). So my question is. What would you guys recommend to raise simultaneously a thousand small platforms? Also this http://tmg-trackr.media.mit.edu:8020/SuperContainer/RawData/Papers/527-inFORM%20Dynamic%20Physical%20Affordances/Published/PDF that the devs made. Doing a bit more research I found that the device they used to move the platforms cost approx $30, I imagine some of this price is due to the fact that there is sensors in it that we don't want or need, I don't think I need to say this, but I don't have $27000 :( Key difference between their implementation and our goal: No real-time interaction with the table. Controlled by and arduino and or a computer is fine. Size of the platforms will be closer to 1 inch^2 All sides of the platform should be light up, but I believe this is mostly a question of choosing the right material

• Answer:

  You could actually do this relatively cheaply using a mechanical solution, assuming you're happy to put up with a fairly long reconfiguration time. What you need is an X/Y axis CNC setup, a servo, a whole bunch of worm gears, and a small motor. The idea is that you'd build each platform with a rack on the bottom, connected to a worm gear, such that the platform would raise and lower when the worm gear turns. The reason for using a worm gear is that the platform will stay put even if no tension is placed on the worm gear. A rod connects to the worm gear, and has a small cog on the end of it. From there, you mount the X/Y axis CNC bed under the array of platforms. On the "head" (I don't know the proper term) you mount a servo, and on that you mount a small motor with a cog on it. The servo rotates the motor chassis so that it sits clear of the rods I mentioned in the last paragraph. The X/Y axis moves to position, the servo moves the motor upright so that it now touches the cog on the rod, and the motor spins to adjust the platform height. The servo then moves the motor chassis back into the "clear" position, then moves to the next platform. Rinse and repeat for all platforms. Here's a horrible MS Paint drawing: You could reduce the complexity a little by omitting the servo and just maneuvering the motor around the hanging cogs, or by using an X/Y/Z axis CNC bed. This ensures that your cost is pretty much limited to a CNC bed, the fabrication of the platforms (3D print them, maybe?) and a bunch of mechanical parts; the motor, servo, and controller stuff should be super cheap anyway. You could even drive the whole thing from an Arduino stepper shield. With a bit of cable management you could trivially wire LEDs into the bottom of the platforms, or you could go for something fancy like leaf springs to connect to a pair of plates on the side of each platform.