This clock sculpture was a month long design project in a group of four for my class Mechanical Prototyping. We went through all of the stages of from initial ideation to assembly of the project. We used SOLIDWORKS and collaborated over GrabCAD. This project particularly stands out to me as a lesson on how to adapt to obstacles, as one of the people in the group was from a different school and had to leave the country the last week before the project was due for their spring break.
This Clock Sculpture portrays the story of Icarus using three distinct visual mechanisms. On the left is the primary mechanism I designed. Daedalus is working in his tower workshop on the wings for Icarus. He is moving a saw back and forth using a scotch yoke and a simple two bar linkage. Moving to the right is Icarus, the centerpiece of the project. Icarus is displayed with a bold red acrylic and has large wings coming out to either side. The mechanism for Icarus uses a linkage in addition to a constraining slot to move him up and down, rising towards the sun before crashing down to the ocean below. All the way on the right is our representation of the sun. The sun is dripping wax and contains a golden clock in its center. The wax was hand crafted using model magic. Additionally, some of the wax “drips” down. This is done using a cam which two of the drips are connected to making them move up and down. The final visual is a set of blue acrylic waves set at the front of the piece and a light blue that is painted on the background. Here is a picture of the fully assembled project:
To power these mechanisms, we used a belt drive behind the main panel. All of our mechanisms get their rotational motion from the same plane, so all of the axles were easily connected to one belt. We split everything up onto two sets of plates. The workshop and Icarus were mounted together, and the clock’s cam system was mounted along with the tensioner and motor for the belt. These plates were offset from the back of the panel using a series of standoffs. The motor is controlled by a simple circuit and can be turned on and off using the switch on the front to the left of the tower.
Final Project
Final CAD model
The main mechanism that drives the saw is a scotch yoke. The wheel was 3d printed out of ABS and the yoke was laser cut out of Delrin. Square bushings were used so that the parts could all be laser cut out of Delrin. The bushings were originally a bit too tight, so I used a file to get the movement smoother. The bushings are mounted onto aluminum angle stock which I cut a hole out of with a mill to allow the yoke to fit through it. Originally the whole mechanism was designed to be perpendicular to the front panel so that the yoke would move in the same plane as the saw’s movement. However, we wanted to mount it the same way as the other two mechanisms to simplify everything, so the belt would be easier to design and put on. This was a simple change to implement as I was able to just add a ninety-degree bend to the 3d printed saw, and it removed the need for ninety degree gearing.
Rear of project with belt and mechaisms
Saw Mechanism that I designed
The wax sun is a very cool mechanism because of the artistic qualities it portrays. The model magic wax is beautifully done by one of my teammates and really serves as a finishing touch for the entire sculpture. With that said I ended up doing some of the leg work for the cam mechanism. Specifically, I designed the cam follower, its bushing, and the 3d printed parts which connect it through the front panel. This can be seen in the image to the left. The follower was turned out of Delrin with a rounded tip and a tapped hole in the top. It took some getting used to working with Delrin on the lathe and I realized I needed a much slower feed than I initially anticipated.
Cam mechanism I designed
The dripping wax which moved by the cam
Technical Drawing of piece of scotch yoke mechanism
Technical drawing of bushing for scotch yoke mechanism