Jenny Moralejo (HTMAA 2019) Week 01 Week 02
Vinyl Cutting Laser Cutting
Week 03 Week 04 Week 05 Week 06 Week 07 Week 08 Week 09 Week 10 Week 11 Week 12 Week 13 Week 14 Final Project
Week 6

Computer Controlled Machining

Make Something Big

Brainstorming and Initial Designs

I was inspired by the image above when deciding what it was that I wanted to make big. I decided I wanted to make a staircase (where the height of the steps is proportional to how much the average woman from that group of Asian-American women makes in comparison to the average non-Hispanic white male) that would highlight the discrepancies in pay between different groups of Asian-American women. Unfortunately as you can see in the above image, there are many different groups highlighted and the staircase would be disproportionate for the height I needed it to be, if it were to have 20 steps. I thought 10 rather, would be more reasonable to make. Based on this, I looked up the populations of Asian-Americans in the U.S. (unfortunately I wasn't able to find populations of women) and created the following table based off the 10 most populous groups.

Group of Asian Americans 2010 Population (millions)
Hmong .252
Cambodian .255
Pakistani .38
Japanese .84
Korean 1.4
Vietnamese 1.6
Filipino 2.6
Indian 2.9
Chinese 3.5

For all of my designs I kept them parametric by storing relevant dimensions such as the material thickness, total height, width, depth, joint width, as well as the proportions for different Asian-American groups in a separate easily editable file that would cascade down to all parts of the staircase. While numbers and other parts of my design changed, I consistently designed the staircase to be held together through the use of finger joints and other holes.

Design 1

For my initial design, I completely disregarded material and machine constraints, due to negligence. I initially designed the staircase to measure 70" x 64", with a one piece back that the vertical supports would fit into. Unfortunately the machine bed can only fit a 4' x 8' piece of wood. I didn't want to compromise the 10 steps, width of the staircase nor the height so for the next iteration I designed the staircase without a shelf back.

Design 2

For my second design I removed the side joints that would allow the vertical supports attach to the back and slightly increased the width of the middle joints that allowed the horizontal components to attach to the vertical ones, for more support. Unfortunately after consulting with more qualified MechE people I came to the conclusion that the horizontal joints I had were only half the width of the OSB sheet and the quantity of these joints were too few to be stable. Furthermore there was no horizontal supports on the bottom, making the first step very unstable. For the next iteration I added in all these design considerations

Design 3

For the third design I added in a bottom horizontal support and made the joints go all the way through the wood, by stacking them, rather than having two horizontal supports be perfectly aligned but not as secure of a joint. I also added in tolerances to the joints by offsetting entities and decreased the height of my model as well as the depth to try to fit everything on ~2 sheets of OSB. Unfortunately due to time constraints, this design was no longer feasible for me to construct.

Final Design

Thus in the final design I only took the 7 most populous groups (10 parts total), significantly decreasing the required material. Unfortunately, because my design was based off of having 10 steps, it was not as flexible when changing it from 10 to 7. I also reduced the amount of horizontal supports I cut out to reduce the required time. A sample (unmated) picture of the partial assembly is above to illustrate said changes.

Creating a MasterCAM Toolpath

Using this design I exported all of the required parts to Rhino where I laid them out and added drill holes. This was then exported to MasterCAM where I added the cut path for each of the interior holes and Zain helped me with the exterior. Unfortunately it was at this point, we realized I had set my tolerance to .1" rather than .01" and thus we completed this process again with the files with the correct tolerance.

Cutting

Finally with the toolpath created, I was able to cut and everything went very smoothly.

Assembly

Because OSB isn't the best material, when the parts finished cutting there were still a lot of very jagged edges. I took each part and individually filed down the material, as the router was down. I then sanded down each part twice changing the grain from rougher to smoother to make the OSB smoother and more presentable. Then each part was fitted together with a bit of glue. Because we were only limited to one sheet of OSB I laser cut out some sheets of acrylic to give the structure more complexity and also a pop of color! The time I spent changing the joints definitely paid off as I was able to successfully stand onto the third step of the staircase. I wasn't quite ready to try going to the fourth however...

Reflections

Because this project took up so much time, and was quite meaningful to me I thought it was only appropriate to reflect on it. I think it is very important to dispel the model minority myth and highlight the inequities within the Asian-American umbrella. I am satisfied with how the project turned out and it was definitely a lesson in planning and patience. Going forward I think it would be worthwhile to recreate this project with more high quality material and complete the larger design I wasn't able to initially (unfortunately, this design still has the tolerances set to .1" haha). I would also love to paint the OSB but because it is so absorbent, it might prove to be very difficult.

Important lessons learned: