Final Project: The Building Process

The Goal: 
Create a mat that follow our design while also being safe and usable for the children in the classroom environment.

The Spinner:
Although we decided against our original plan to use the spinner to wirelessly decide the color the mat would be sensitive to, we wanted to keep the spinner as part of the design in order to provide a concrete visual reminder to accompany the verbal cue given by the teacher. This way there would be reminders from multiple sensations which the teacher said was best for the children's learning.

Also in our initial design we were going to use the traditional carnival wheel style of spinner with pegs and a rubber wedge that would pass along the pegs and choose a color. After thinking it over, we decided to simplify the design by creating a spinner without pegs that just used gravity to slow. If the delrin caused it to spin for too long then we could add a piece of foam or carpet like spot to create more friction to slow it down. Below I have included the solid works parts for the spinner and the test piece I made.

In order to create the red and blue sections of the spinner we originally thought that spray painting them would be best, but then we realized that making stickers in the shape that we wanted would be better. It just so happened that they was vinyl sticker rolls in the classroom already so we didn't need to buy anything! I created a stencil then cut out the vinyl and stuck directly onto the delrin. The final product  and stencil is shown below.

The Mat:
Trying to figure out what material to make the base of the mat out of was pretty challenging. at first we thought delrin would be good but we were worried it would be difficult to make a really strong box with delrin and that it would be too heavy. Then we thought maybe thin wood would work, but that wasn't good because if it splintered then it could be a safety hazard. We finally decided that the bottom of a bin that we cut the top off of. Then we made a smaller delrin box that would contain the bread board, the battery pack and the arduino. We made small holes in the top of the box to rest the button sensors and we ended up cutting out access squares to get to our bread boards to adjust the wires. For easy access we hinged the arduino box to the bin. We used the top of the plastic bin to stabilize the red and blue mat sections so that sitting in just one section would make the button compress. We then hinged the mat and plastic combo to the edge to open up for easy access. I added Popsicle sticks to the edge to give it a little more height to make the angle less steep.

The wiring proved to be pretty frustrating. It got pretty complicated and sometimes a connection would become loose our disconnect entirely. Also, we made the wires too short to lift up the delrin box we made so that made things frustrating to fix. Otherwise, the soldering went fairly well

Below I have included pictures of the solid works parts and the various stages of construction as well as several views of the wiring and soldering components of the process.

Reflection: 
I found the process of physically building our mat very liberating. Seeing our idea go from hurried sketches on a paper to a physical and usable object was one of my favorite aspects of this project. As always there were some unforeseen problems and bumps along the way. Some examples include making the wires longer so that we could have lifted the internal box without disconnecting the wires. Another was making sure that the screws in the hinges didn't interfere with the motion of the lid. This required a lot of guidance from Larry since he showed us how to grind down screws as well as do all the other things we needed to do. This process also emphasizes in my mind the necessity of prototyping and creating test pieces before the final product.