My Work
First let's watch our machine!
We designed a little box to cover the step motor as the MTM tools do. We want to make the DC motor and step motor together in a little box. So we designed a box with a wooden arm.
For more details you can refer to the follows.
1. Introduction
The group project by Shanghai Fablab this week is to create an ultimate useless box. Useless box is useless because it does not generate any value. The box has a secret hand inside it. When someone moves the switch, the hand will come out and return the switch back to where it was. This series of action does not lead to any real change, so this is why it is so useless. However, ultimate useless box is even a greater idea, because it has three switches in a row. When someone chooses to move any of the three switches, the secret hand will move to the right position and return the switch. Although useless box has no real value, it requires a lot of technical work to complete this project. Let me tell you in details how to create such a useless thing.
2. Sketch
The first step is to sketch the design. The whole making process can be divided into several parts: i. design the structure; ii. design the mechanical structure; iii. programming. We use illustrator to design the structure and decides to laser cut it. The box is to no one’s surprise, but we need to leave enough space to store everything we want to inside it. We use some special cardboard which is really firm. This box design somehow reminds me the birthday cake I had with my cousin last week. We spent quite a while to design the anchoring part of the box. We jtest the length of sloth and design the following pair of shapes as a match. The box has to be stable. Otherwise, we will have trouble in accuracy when the secret hand actually moves. One can see ten holes in two pairs on two sides of the box.
This is the place where we set our guide shafts through the holes. The three buttons are set as follows with equal amount of length between each pair. We drilled a hole on the top of one side for the setup of our power.
There is something that I want to emphasize here. We use press fit for the anchoring of the corner. One can see how we avoid a difficult situation. Our press fit is not a good design because the space of the sloth is bigger than it is supposed to be. We insert some extra small pieces into the spaces in the middle to complete the press fix design.
In order to complete the controlling system of this ultimate useless box, we use several things that are quite crucial for our project. Lead screw is our key to actualize the movement of our secret hand. On the end of the lead screw, we use one motor to generate the action of pushing by the secret hand. The controlling system based on the PCB board took us hours to complete. We used what we learned in the previous two weeks. We made two boards, and used an Arduino to complete the whole controlling system. The two boards correspond to the two motors. Arduino is for the central controlling.
3. Program
The programming has a lot of technical details that we need to deal with, but it has no real difficulty that is hard to conquer. The Stapper Motor is good at measuring the relevant distance, but it cannot measure the absolute distance. One can deal with this situation by setting zero each time when we open the Stapper Motor. Then we keep moving the arm until it touches the switch. Then the arm will move itself to return the switch. This algorithm can be found in our documented file.
In the future our fablab want to make more things like useless machine! Because there are much fun in these machine. First of all, we want to add more "hands" into the machine to make it look more useless.