Project Update 2

This week, it feels like I have accomplished quite a lot! It’s really satisfying to see my ideas slowly becoming more tangible, and my previous skillset more-or-less matching my artistic vision.

FORMAL PROJECT PITCH

During the pitch, Professor Gleason suggested several changes:

• The box should be larger than the paper mock-up I brought in
• The box should include a moving component – something interesting, but not too distracting. I have modified my design to include a small gear train that spins when the lights turn on.
• Only two buttons  are going to be on the final design (in addition to the photocell). If this is still too much for specific kids, some of the buttons can be fixed with tape.

Also, while I was at the CSC, I got the dimensions of a name card.

HARDWARE

-Arduino-

 

-Gears-

The original gear train was much larger and more complex, but with the smaller box, a smaller gear train was necessary. It is still interesting though (and it thankfully doesn’t need to generate a set torque or speed).

-Motor-

The motor is going to be inside the box, so it will have to drive the gears from behind. I attached a Servo motor to the arduino to drive the gears. Because I was using lego gears, which were threaded differently from the piece that attached to the servo, I needed to drill press a large enough hole into the lego. The lego now fits onto the axle, but I would like to use some form of adhesive to make sure it doesn’t pop off and wreak havoc inside the box.

-Box-

I started out with square faces, but then realized this box was too bulky, so I made the sides half of the height.

My next step was to make sure everything would fit inside, aka engineering Tetris. This was definitely more difficult than I had anticipated, because so many of the parts had fixed locations:

• The photocell needs to be on the bottom
• The motor needs to drive the gears from the inside
• The LEDs need to be on top
• The battery pack shouldn’t have wires crossing it
• The battery pack must be accessible (for when the batteries run out)

The way I have had the most success with thus far is creating a second level, but punching holes in it where it interfered with other parts. Even with this, I foresee copious amounts of tape holding everything in place until I finalize my design.

I plan to make this “divide plate” a press-fit peg/slot joint into the sides of the box.

Once I got a sense of what I wanted my box to look like, I modeled it in SolidWorks and took it to the laser cutter, intending to cut a foam core model of it. That was where things got… interesting.

I hadn’t realized that the laser settings reset to “Wood : Plywood” before each cut, so I assumed that the settings were correct because another team had cut foam core just before I had. Events transpired, and my foam core caught on fire. Unfortunately, I didn’t take photos to document the truly incendiary event. Thankfully, everything proceeded smoothly – with Julia’s help, I paused the job, moved the laser cutter head out of the way, smothered the fire with the fire blanket. At the end of the day, I think this was still a positive experience, because I learned how to deal with surprises, and all that was lost was time and some thoroughly smoked foam core.

Additionally, one of my pieces came out the wrong dimensions, so I will be adjusting and then re-cutting it.

-Materials Order-

My materials order is as follows:

https://www.adafruit.com/product/1502 [Button]	1502	$0.95	2
https://www.mcmaster.com/#8560K171 [Acrylic]	8560K171	$4.99	2
Wood – 15 x 10 x 0.5 cm	6 x 4 x .2 inches		7
15 x 5 x 0.5 cm	6 x 2 x .2 “		4
10 x 5 x 0.5 cm	4 x 2 x .2		2

From the classroom, I will also be using:

• 4 LEDs and LED holders (the black things)
• 1 photocell
• Wires, solder, heat shrink tubing
• 1 Arduino Uno (without a breadboard attached)
• 6-AA battery pack
• Screws, threaded case
• Adhesive, possibly epoxy and/or wood glue

The tools and equipment I will be using:

• Laser cutter (new favorite tool)
• Drill press
• Handheld power drill/driver

SOFTWARE

The program works, in that it fulfills its intended purpose, but there are definitely  improvements I plan to make to it. For starters, it needs to be debounced so the light doesn’t strobe obnoxiously when held at a certain height. Secondly, I want to modify the motor code once I fix the gear to the motor and text it on the actual gear train.

 

NEXT GOALS:

Finish foam core box with buttons

Create the box out of wood and fasten everything together

Integrate buttons and solder everything together

Debounce program

Stick the gear onto the servo

Adjust motor program