Tuesday April 12, evening

After getting the parts and doing some testing we decided to take a trip to Home Depot to get the rest of the extra parts we would need to begin construction. We got a cheap 2 foot by 2 foot flat particle board used to mount the tracks on. The reason we got this board was because it was perfectly flat and the sides are perfectly straight. We need the board to be perfectly flat so that the tracks can be mounted flat and give minimal resistance to the stepper motors. The edges needed to be perfectly straight so that it would be very easy for us to mount the two bottom tracks perfectly parallel to each other. If the bottom tracks were not mounted perfectly parallel, the stepper motors would only be able to move in the X-axis direction a limited distance before stopping at some arbitrary location instead of going the full two feet desired range of motion.

We also got a 7/8" thick board. Smaller pieces of the board will be used to mount the two stepper motors to X and Y axis tracks. A longer portion of the board will be used to connect the bottom two tracks together to get the X-axis motion. Then on top of this board the Y-axis track will be mounted.

In addition we found some metal disks that we could use to place underneath the computer pieces. Earlier that day we decided that washers would not be good to use because the magnet is only attracted to the metal and wouldn't facilitate exact placement of the piece when it is pulled. Therefore we needed solid metal disks. These were found in the electrical department; we just had to pop out 16 metal disks from two cheap metal electrical holders:

After Home Depot we stopped by A.C. Moore to see if the had some weaker magnets that we could use for the human's pieces. Sure enough they had a good selection, and they were all cheap. We got two separate kinds. As shown in the figure below, we will be able to pass the metallic disk computer pieces relatively close to the weaker magnets without them being attracted:

We still are waiting to receive the reed switches before we can determine exactly which magnet we'll be using on the human's pieces. However, no matter how hard we try, we're still going to have a problem with the magnet underneath the board attracting the magnet pieces of the user. Therefore we suspect that we we'll just use sticky tack to hold down the user's pieces since they don't need to be moved by the X-Y position system anyway.
Right now we are predicting that the board will be two feet by two feet, which will correspond to three inch by three inch squares. The board will be a little bigger than a normal board, but it will still look good.