Introduction
For our midterm project, my partner Isaac decided to create a V8 engine. To accomplish this, we would need to use laser-cut material, water jet cuts, use post-processing methods, and cut vinyl stickers to embellish it. Below is the entire process with images and files attached for this project.
Files (Make your Own!)
Illustrator File: Lid_Is_V8_Engine
Rotary Phone Dial: circle rot
PowerPoint of Components: https://docs.google.com/presentation/d/1DyxJnoSlkRYVmEUGlqdBFdaBU5DtVdw9RDYbsieJ-gY/edit?usp=sharing
Development
We divided our progress into three progressive fidelity types where functionality, aesthetics, and durability increase as we go towards higher fidelities. For example, for our lower-fidelity prototypes, we focused on proving that our mechanism’s crankshaft would work whereas in high-fidelity models we focused on the smoothness and attractiveness of the model. Below you can see the successive progression of our V8 Model and the modifications/struggles we endured.
- Low Fidelity
Concept Sketch of our Model. No dimensions are provided yet.
Connected Y Frame with Piston Holes
To start our low-fidelity model, we began by making a conceptual sketch (see above) and then cutting the parts using cardboard and cheap wooden dowels. The first component created was the engine box, where two Y-shaped frames would be interconnected by 2 long planks of cardboard with 4 piston holes and a single base layer. After connecting the frame, we took time to design a working crankshaft with a 90-degree shift in periodic motion per offset. TO simulate movement, we inserted the crankshaft into the box and tested how well it spun. We even run it with a drill and it helps up! With a promising structure, We continued to improve our design.
Cardboard crankshaft with wooden dowels
To finalize our low-fidelity prototype, instead of creating cardboard pistons (they wouldn’t work due to the binding and friction between two cardboard surfaces) we used napkins to see if the crankshaft pushed and pulled. As seen in the video below, it could, and therefore, we continued to our next fidelity model.
Video:
- Medium Fidelity
For our medium-fidelity prototype, we replaced all the cardboard components of the low fidelity with laser-cut wood components joined with finger joints. Aside from re-making the frame, we also laser-cut the pistons and the crankshaft camshafts to have a completely wooden prototype.
These shells were used to make hollow pistons.
The long and small cams are laser cut and attached to the dowel.
Fully assembled piston. Still subject to modification.
Since these were the major parts of our engine, we needed to make sure the pistons were perfect. It took a lot of camshaft adjustments to get the correct displacement from the crankshaft and the connecting rods. Additionally, we had to sand the holes we cut for the pistons and the pistons themselves because the laser-cut material created too much binding and friction (at the burn sites) which made the pistons sticky and would not flow smoothly. After adjusting all the components, we proceeded to use the medium fidelity model and upgrade it instead of creating a different one.
- High Fidelity
For our high-fidelity prototype, we assembled more piston racks and glued them together. Then, we sanded the racks and the pistons to allow smooth motion through the holes. The rest of the build was added to the aesthetic and smoothness of the engine: More sanding, staining, cutting out steel parts, and vinyl stickers. After everything was optimized, post-processed, and assembled, we got a smooth, working Engine!
Stained Camshafts and Connecting Rods
Vinyl Cut Tinder Logo (Easy cut Vector file)
Glued, Sanded, Cured, and Stained sides to create a nice look
Staining the entire engine block.
Steel Dial and Name Plate on V8
The final result?
Improvements
Though the machine came out smooth and well made, there were just many problems with the pistons. The first one was creating the correct amount of displacement, and doing so involved a lot of calculated trial and error to get a displacement that looked satisfying to watch. Another problem was the binding experienced by the pistons sliding in and out. Initially, we had used laser-cut material, but the ashes were sticky and the pistons would not move. After sanding, we were able to get smoother motion. Another problem with the pistons was stain, and hence we did not give them color. The stain gave us the same problem as the ash from the laser-cut wood – It was very sticky and didn’t allow motion. The only solution was to sand thoroughly and make the pistons wobble slightly to give them as much sliding motion as possible.
Cost Model
Laser Cuttable 36″ by 48″ Birch Wood: $9.67
BEHR American Chestnut Stain and Poly: $19.98
Verathane Black Stain: $12.98
30 Hours of Labor at 15.00/hr: $450
Total: $492.63
