For Machine Building Week, I was part of the fabrication team in IDC (and also worked on assembly).

Machining in IDC was quite interesting for this week, because not only did we manage to break a couple of endmills. But also because, as we were apprecaiting how there were no clamps or adhesives (other than air vaccuum) used to secure the piece, the piece came off. At the begining a cut off piece lost contact with the platform, comming off while I was watching the mill cut. I stopped the mill, and went to inform Zach right away. Luckily, we were able to solve the problem , which other sections learned from later. The broken endmill, however, was due to two reasons, one is the speed at which the mill was running at, and two due to the accumulation of plastic "debris/shaved off bits" on the endmill itself.

In terms of laying out the board, we had it layed out on Rhino, and had to have each of our holes in different layers. Miana was piloting this part, but Vivian, Ivan, and I were all there to help. Because we initially had all of the cut traces in one layer, it was cubersome to manually select holes and place them in seperate layes according to size (especially since none of us were savvy with Rhino, which if we were, I assume we would have been able to write code that would do that for us). The reason why we had to separate hole sizes into different layers was for cutting purposes. Zach suggested that we cut the holes first, and then the contours of the actual pieces.

I was also responsible for deciding the screw sizes, and bolts that we would need, and sending them to Zach to order. We had a couple of sizes, and I used a standard screw chart to decide on the sizes, which can be found in this link. the General rule for naming convention is

M(D)-P x L

M = Metric thread designation

D= Nominal diameter, in millimeters

P = Pitch (distance from thread to thread), in millimeters

L= Length, in millimeters

The sizes that we used for the bolts, nuts, and screws were as follows:

Bolts: M4-1.0 x 25mm

Nuts: M4-1.0

Screws: M3-1.0, M4-1.0, M2.5-1.0

4.2 mm bolts

3/8th thickness (of one layer)==> need length of at least twice that

3.25 mm diameter screws

2.51 mm diameter screws

4mm diameter screw

(Screws got motor should come with it)

Assembley and Belt Mechanism: I was responsible, along with Vivian for adding the rollers to the axis by threading and adding screws. In the begining, we did not have a threading tool (or at least were not aware that there were was "one" in lab), so we just manually inserted the screws into their respective holes to attach the rollers. Since I happened to be working on the y-axis portion, I noticed that the washers weren't actually sitting on their respective platforms to ensure smooth roller coaster movement. This was due to the fact that Rhino, for some reason, decided to cut the traces for the y-axis platform piece using an "inside" trace, rather than an "outside" trace. This resulted in having a smaller platform piece for the y-axis. However, Prash suggested we use small washers, and it worked!! We were able to have th mounting y-axis piece snuggly fit into its platform.

Although I wasn't with Vivian to actually assemble the belt mechanism (due to other appointments I had that day), we looked at the sheet provided for the belt mechanism to deduce the assembly and pieces required. Initially, Vivian had only 3D printed a couple of parts that were not sufficient for one axis. So, after pulling up the sheet, we corrected that, and 3D printed the correct set of numbers.

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