Process: Inner Pyramid (Ellis Cordaro)

Process: Inner Pyramid (Ellis Cordaro)

Ellis Cordaro

The initIal idea for the portable party project was a pyramid that would have a speaker inside of it and would attach to a bike. The pyramid would be powered by the cyclist (chain driven) and would be able to change volume based on the user's speed and would have a lifting top to sound could escape. When everyone came together to integrate their ideas with one another's we split into groups based on the general use of the product. Beverly, Josh and I all wanted to make some sort of lighting fixture for the party. So, the bike mounted pyramid morphed into a compact and portable light fixture. In addition to the pyramid, we decided to add an outer pyramid which had a smaller pyramid enclosed inside of it. It also included smaller pyramids lining the perimeter of the inner pyramid. We then split up the work between the three of us. My portion of the project was the inner pyramid which originally included lasers, a projector, LEDs and a fog machine. However, the group decision was to get rid of the lasers and projector. We also decided to move the fogger to the bottom of the larger triangle.

The next step was prototyping. The  prototype included a truncated pyramid with a height of 6" with 4 trapezoid shaped sides and a square base with a width of 12". The top half consisted of 4 triangles with a base measuring 6" and a height of 6". The prototype was laser cut and was made from 1/8" plywood and the panels were joined by wood glue. The next iteration included the same plywood panels but was joined by polycarbonate strips and screws. Unfortunately, the strips did not provide adequate support. A wooden frame was then designed for each of the panels which were now made from HDPE. Next, hinges to join the panels to the base. I experimented with many different materials to join the panels to each other. It was decided that 3D printed brackets would be used to support the panels. Unfortunately, they did not print correctly and broke immediately. So, instead of making the brackets from an extruded square, it was necisary to draw the profile of the bracket on Rhino, extrude it, offset the surface and added a thickness of 5mm. There was also an effort to use brackets for the top pyramid. However it turned out that the holes would have to be so close together that the bolts prevented each other from being attached to the panels. So, with the last work day approaching, the top panels of the pyramid were hot glued together.

Another large part of creating the inner pyramid was making the lifting mechanism for the top. So, using a CAD software for making gears, a three spoked gear was made and attached to a motor. A notched acrylic rod was also made to would fit inside of a bracket holding it to the top triangle. It was originally attached using a 3" wide 3D printed pyramid bracket. However, the 3D printed pyramid was useless because the slot for the acrylic diagonal instead of perpendicular to the edge. So, it was substituted by a laser cut panel with a slot that used an acrylic solvent to attach the two pieces to each other. The panel was then attached to the pyramid head using hot glue (because of time constraint). The motor also needed an acrylic panel that would position it correctly and provide a guide for the notched acrylic piece. The motor ended up being attached to the acrylic using tensioned fishing line. After changing the tolerances of the slotted plastic many times and adjusting the motor, it needed something else to guide the rod. So I made an acrylic piece that would attach to the same panel that held the motor which had bearings on it and acted as a guide for the acrylic rod. One problem was that the motor was hitting the inside of the top triangle preventing it from closing completely. So, the entire panel was flipped upside-down (as suggested by Sean). The final steps to finishing the inner pyramid was attaching RGB LED strips and wiring the motor that was connected to a servo and attached to an arduino which Josh programed. Because of a lot of other work to do on the other parts of the project, the LEDs never got programed. However, on a positive note, the motor mechanism worked quite well.