Assignment – Implementation and play testing for your curious cube.
A curious cube moves needles to the center when user approaches, and goes back to the original position when user leaves.
People who are close to us hurt us the deepest. We carry the scar with us and build the wall for the next one.
School will be cancelled on Wednesday, Mar. 11th because of the Coronavirus. My time frame has been shortened. The cube shown is my prototype for something bigger. I really want to realize my project and make it into a bigger version and better version.
I wanted to create a cage for the human-figure to convey a message that we are within the box we put ourselves in. I want to carry on this for my final project since the motors I used are too weak in terms of torque power.
Working with motors
The pins for the JST female header attached on the mini stepper motors are too small for me. I then took out the header, used wire wrapper tool from David Rios, and then soldered headers individually to the motor.
I then checked for continuity of the motors and figured out that the 1st and 3rd wires are for one and 2rd and 4th wires are for another set.
Last week, I chatted with Jeff Feddersen and he advised me to start experimenting with one motor driver for several stepper motors in terms of serial and parallel circuits since I am working with mini stepper motors which do not need lots of power.
Ideally, I wanted 8 motors. Therefore, I started with one EZ motor driver and one motor and then I increase the amount of motors to see how they work.
Insight: One EZ motor driver can power 4 mini stepper motors with 5V from Arduino Uno.
I have been consulting with so many people to figure out a good way to create an enclosure for the stepper motor. Nicole has been so helpful that she helped create a 3D version of the enclosure for me. I tried to 3D print yet it was not as ideal and the support for the empty circle part is too difficult for me to get rid of. I spent around four hours learning how Nicole did in Rhino and trouble shooting with 3d printer twice. The end result is not pleasing so I went back to making the enclosure in acrylic using laser cutter.
I am proud to say that I am a master in building enclosure for the mini stepper motor. I incorporated what Nicole has suggested and built something more stable upon the structure.
Here are several iterations of my enclosure design:
I used the matboard material and laser cutted the design.
I further measured the dimensions and played with the distance of the rack and the enclosure itself. Here I was trying to create an open enclosure.
3D print model and failed 3D prints. I used the 0.2 Nozzle in Ultimaker since it is the finest I can get on the floor of ITP. Yet, there were something wrong with the two printers I experimented.
Version 4 – Close to final version
I spent a lot of time to figure out the perfect enclosure design through:
- dimension measurement [I measured]
- layer design to allow the movement of the rack and pinion and make them secure
- layering of acrylics [I had to print out versions of the design to make sure the amount of layers]
- materials to go through [I was in between the tiny needles and the wire. I chose wire since the needles will make each layer so tight that it would prohibit the movement of the motor]
Final Design Files
I used the following draft to plan out the exact size of the box and the cut out for the wire to go underneath.
Sensor & Code
I did test with the IR sensor from the Shop, here is a video of me playing with it.
I used AccelStepper library to code my project. The EZ driver is super easy, I love it!
Here is the circuit for it.
I had several issues with the torque power of the motor. It was actually an issue since the beginning. Yet, I was too focused in building the enclosure to spend time tackling it.
It actually works when the layers are not tightly tied together. In this case, I only used one wire to connect two hole rather than four holes. It worked better before I glue the enclosure down to the box.
The video shows how when you press down, the motor stops moving the gear.
Ideally, I will use a stronger motor to achieve what I want to do.
This is a rare case where 3 of them are sort of working, but still with the torque problem.
Looking back at my timeline, I realized that I didn’t do user testing with others too much to get insights. I also didn’t realize I spent so much time building the enclosure for the mini stepper motor. For my future project, I would like to build the rough normal size one first to get things going and then user test as soon as possible to get feedbacks. After that, I will finetune and scale down or up the size.
For my final project, I will start building with the normal unipolar stepper motor and EZ motor driver to create the cage that is similar to what I pictured originally. Then, I would hopefully make the cage bigger and incorporate Kinect in the piece.