Initial Sketches

I approached the design of this system starting from the final concept that I wanted to create. I knew I wanted to create something that was space and other world themed. I started with the vision of a rocket and even considered including some dinosaur that the rocket was escaping from. In order to mimic an evacuating rocket, I knew I needed some vertical motion. After looking through 507movements.com and at other ENGI 210 midterm projects, I discovered the rack and pinion movement and modified it to suit my specific needs.

I designed a train and track for rack and pinion that would keep the train on the track. I created a system that used two racks and pinions because I was planning on creating a 3D rocket so I thought the ship might need the support of two racks to lift it. To make the rack and pinion I used a gear I found on instructables.com and made my own rack for it in Figma. 

Figure 1: Figma sketch of the rack and pinion

To design the ship, I took inspiration for a few laser cut rockets I found online. I started with designing the curvature of the sides of the ship and then I decided that I would use 15 slats to accomplish the 3D shape. To create a circle with 15 slats, I created an asterisk with 15 points and overlaid that onto a circle to see where the slats should be. Since no matter the size of the circle the slats should be at the same angle as the 15 pointed asterisk. To find the radii of the supports I reflected the original slat piece and found where I wanted the supports to be and that the radius of those supports should be by overlaying the circles onto the pieces.

Figure 2: Figma sketch of the rocket

Medium Fidelity Prototype

Before I laser cut the whole system, I had to do some specific wood fittings which is why my medium fidelity prototype included a few high fidelity materials. I printed some smaller versions of the slats and supports for the rocket and tested that the fitting of the slats was correct for the width of the wood I was using. Once I found a slat size that worked, I claimed the piece of wood so that I wouldn’t have to go through the whole process again. My medium fidelity prototype also included a cardboard cut train and track so that I could verify that the hole for the dowel was in the right position. Once I had these measurements verified I was able to move to the high fidelity prototype materials and start laser cutting the wood again.

Figure 3: Cardboard medium fidelity prototype

Water Jet Cut Pieces

Originally I wanted to water jet cut the track because in the prototype I found that this area with a lot of wood sliding up against each other produced a lot of friction and made the whole system harder to turn. But I discovered that my track was too big to cut with the water jet so instead I cut the top of the train. This would have the same effect since the top of the train is what is sliding on the track.

Figure 4: Laser cut and water cut pieces

Assembling the Train and Track

When assembling with the high fidelity materials, I began with the rack and pinion system. First I used wood glue to glue the gears to the dowel so that I could be sure to glue the rack in the right place with the top of the train to allow for good gear contact. Then, I used epoxy to glue the wooden racks to the metal top of the train at the right distance from the gears. I wore gloves during this process and used popsicle sticks to mix the epoxy and apply it to the pieces. Since this piece is a little bit of a weird shape it was hard to hold in place to dry so I used a clamp to clamp it between two pieces of scrap wood to dry. A metal clamp is very helpful for holding pieces together while gluing especially if it isn’t something that you can put a weight on. At this point I discovered that the offset of the water jet cutter resulted in an ever so slightly wider train so I recut the track with wider slats to allow for a smoother slide. Once the train dried I inserted it into the track and used wood glue to glue the sides of the gearbox to the track which would hold the gears in place on top of the rack. Once this had dried and was working smoothly I measured a 10×13 inch slat of wood as a platform for the entire project and glued the gearbox to the side of that platform. Then I cut some small washers that I attached on either side of the main dowel to make sure that the gears would not fall off the track after extended use of the system.

Figure 5: Partially assembled track

Painting and assembling the ship

At this point the rack and pinion was done and I got started on assembling the ship. I knew I wanted to spray paint the ship because I wanted more diversity of color with the project. I chose green and grey to fit in with the space/extraterrestrial theme I mentioned at the beginning of this article. I used tape to make the lines of the spray paint straight and I started with the green and then waited for that to dry and then painted the grey. Once the paint had tried I used wood glue to glue the slats to the support and used rubber bands to hold the slats in place while they dried.

Figure 6: Partially painted rocket

Figure 7: Holding the rocket in place with rubber bands while glue dries

Connecting

In order to connect the rocket to the train and track I used a hole in both the train and a slat in the ship and then used a dowel to connect them. I discovered that to use this method of attachment I needed to take out the two slats adjacent to the slat that connects the rocket to allow for the connecting dowel to have the room it needed to connect to the train. I removed these two slats and then attached the rocket to the track using the dowel and solidified the connection using wooden washers.

Figure 8: Washers on the dowels to hold rocket and crank in place

Final touches

I designed vinyl stickers and laser cut raptors to add some finishing touches and decoration to the project. The vinyl cut stickers are used to decorate the rack and pinion to make it look like scaffolding for the rocket launch. I also laser cut some dinosaurs and spray painted the base to contribute to the environment of the whole project. Finally I added a plate with my name and information. 

Figure 9: Product with finishing touches

Cost Breakdown

Below is a chart that breaks down the cost of this assignment. For clarity, I categorized the cost into three categories: Time, Tool, and Material. Time encompasses any labor and machine time. A tool is something that was used to make the product and will not be in the final piece and a material is something that will be used to make the product and will feature in the final piece.

Figure 10: Cost breakdown in USD