Week 13: Machine Design

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The objective for this week was to work as a group to make and automate a machine. We decided to make a "Magic" Chess Board! Our group documentation can be found here:

Central Section Documentation

My Contribution

I was basically on the mechanical team with Richard, Dimitrios, Christos, and Morris. The day after the tutorial by Nadya and James, Morris and I assembled the three remaining stages since we planned on using all 4.

The following day our entire group met up to get most of the project done before the weekend. We were able to get the entire mechanical structure done that day.

Our section really worked well together and everyone seemed to have great contributions!

Challenges

We had three major challenges in designing the mechanical parts.

1. The carboard was a bit too compliant

2. The stages were a bit too bulky

3. The magnets were sometimes too strong and sometimes too weak

Solutions

To impove the rigidity and strength of the carboard, we made braces out of masonite and metal to distribute the loads. Dimitrios lasercut several pieces out of masonite which we basically used as oversized washers all over the structure. This improved the strength dramatically. You can see the braces in the top and right pictures.

We still noticed that the structure flexed too much at the interface between the stages so I found some metal brackets to hold the two more tightly, which you can see in the right image.

The second issue we had was that the stages were a bit too bulky making the table surrounding them too large. As a result, we had to optimize the orientation of the four stages to minimize the dimensions. In the end, we were constrained by the length of the stages.

The final issue we had was having a magnet that was strong enough to move the pieces but weak enough so that it had no effect on the adjacent pieces, especially while they were moving. It was surprisingly difficult to find magnets that met these standards. In the end, Rich realized that if we turned one of the magnets on its side it would give us the perfect strength, so I made a little holder out of an aluminum rod so that it would hold the magnet perpendicular to the table. I hot glued the magnet in place and this was our end effector.

In the end, the board worked great thanks to the programmers and table builders. Overall our group worked great together and I think we're all really proud of our magic chess board.