Car Rack End Cap for GMC

Summary Continued:

This part goes on the end of a car rack fitted for the top of a GMC that my dad asked me to replace because the original ones fell off. These ones are meant to stay in much more securely and not fall off even at high speeds. 

Problem Statement:

Our teacher allowed us to have free rein on what we were going to make, so I reached out to family and friends to ask if they needed or wanted anything. For Father's Day, my dad asked me to recreate the very specific end cap of his car rack, so I tried making it. 

Constraints:

There were no constraints.
 

Assembly:

To make the end cap, I started by making a boss-extruded rectangle that I shaped with cut extrudes on the front and sides. 

I then added an extruded hollowed rectangle in the middle back to replicate the original shape. 

Then I added a cut extrude and a few circular boss extrudes to match the original model, using about three sketches in total.

Then, to add the additional parts on the side that help the piece stay in the car rack poles, I made a sketch on the right plane that I extruded and two sketches on new planes offset from the front plane. I also added some cuts to remove any parts sticking out from the bottom.

After that, I added some parts connecting the things sticking out to the many body, just like the original model.

There were a few issues that I needed to resolve after merging the parts, but it looked the same afterwards.

Design Choices:

While making this part, there were a lot of issues and decisions that I had to make that deviated from my original plan.

The first change I had to make was how to construct the body. Originally, I tried to make just a simple box that I cut into and thought that I would shape it later. However, when I tried to do that, it ended up with a lot of problems and holes, so I decided to first make a solid rectangular prism and then make a drafted extrusion from the top to eliminate the chance of there being holes and such.

Another problem I had with making the model was the two ‘spiky’ offshoots that have parallelograms. Originally, I accidentally made them in the middle horizontally, and tried to just use the move/copy bodies feature when trying to fix it. However, this didn’t work because it resulted in a lot of problems with merging and the like. Additionally, I had to make each part separately instead of mirroring because of the merging problems. 

The final design change that I made was in the printing of the piece, and whether to print in vertically, with the base at the bottom, or horizontally, with the back resting on the bottom. I ended up doing both because I needed two anyways and found that:

1. Where the vertically printed model that a slight bendyness to the spiky parts on the sides of the model, the horizontal one had almost no bend. The original model had more bend to it, but the horizontal one could be stronger and stay on better.
2. The horizontally printed model had a slight slot on the side where the vertical one didn't