Engaging Mechanisms

Partner project (Rachel Farn and Ethan Ye)

Purpose: To create mechanisms that make specific marks and are inspired by particular forms of movement.

Drawing Machine #1

Inspiration (Pinterest)

rolling mechanism

For our first drawing machine, we concentrated on a rolling mechanism that would create circles. However, we felt that drawing simple circles wouldn’t be enough and we wanted to add on other motions.

We created a rotating mechanism that holds three pens and can be manually shifted further and closer from the axis to change the radius of the circle. However, we wanted to add another motion into the machine, so we built two arms to connect to the triangular pen holder that would wiggle it back and forth as the overall mechanism turned.

On the final prototype there were many small details we had to add to make it function properly. Around the gears we had to add a lot of spacers to help it rotate smoothly and prevent it from tilting or getting stuck on the base pieces of the structure. We also added spacers under the arms because the spacers under the gears made the gears higher than the level of the triangle, causing the arms to connect at an angle and tilting the gears over.

We also decided to add a string connected to a post on the freely moving triangle and the middle gear. As we twisted the mechanism in circles, the string would wrap around the middle pole and gradually pull the triangle inward, creating a spiral pattern.

sketch of prototype

The first prototype makes simple circular marks. We found that the wiggling mechanism didn’t create distinct changes in the circle (we were expecting curvy circles). However, the pulling mechanism did work well as shown by the change in radius in the circles.

final prototype

We found that this prototype was extremely rough and complex. Rather than planning the prototype out ahead of time, we just kept adding parts and fixing little details as we built it. In the end, our concept was shown, but the craft and stability of the overall mechanism wasn’t very strong. The idea itself was also very complex; we tried to add many functions and movements into one device (rolling + wiggling + pulling inward).

Drawing Machine #2

Inspiration (Pinterest)

rotating mechanism

For this machine, we decided to create something simpler and to concentrate on the gear mechanism.

We used three gears to create a drawing mechanism. One with an arm holding the pen, one with an arm to guide the pen and a third gear to turn the other two gears.

We used chopsticks as the axis for the gears and pinned the arms to the gears with thumbtacks.

sketch of prototype

From this prototype we learned how craft affects the machine. The design itself is extremely simple, but we found that often the ridges on the gears wouldn’t connect. This happened either because the gears weren’t perfect circles so at different points of the circle the radius was different lengths or because the ridges weren’t strong enough and would flatten.

Drawing Machine #3

Inspiration (Pinterest)

Accordion arms

All past prototypes relied a lot on gears to function. For this machine, we wanted to create something without gears.

Similar to the inspiration photo, we created accordion arms that fold up and expand. We used the mark making tool (pencils) as joints as well. A person holds the two handles on each end and pushes and pulls the device around to create marks.

sketch of prototype

The marks of this prototype were very random. There was no continuity, repetition or unity in the marks.

For this prototype, there was a lot of user interaction necessary. Majority of the variables were controlled by the person pulling the two handles. Also, we built a track to guide the handles and keep the marks and mechanism contained, but it wasn’t really necessary. Without the oval track, we easily could have created the same marks. Another thing we could have changed was the mark making tool. It may have made a more distinct mark if we had used pen with ink or brushes with paint instead of colored pencils.


After experimenting with various mechanisms and creating different marks, we decided to go back to the concept in our first prototype (Drawing Machine #1) and refine and simplify it.

I sketched out a general exploded view of how the rolling mechanism may be disassembled and reassembled. I also show close up how the wheels are taken apart.

Refinement #1

For the first refined prototype we kept the rolling mechanism, making a machine that rolled/ rotated in a circle. We also reused the gear mechanism concept to create an arm that would move in and out as the machine rotated.

On this prototype, we simplified and cleaned out all the spacers under the gears and around the axis of rotation of the machine. Instead of having multiple functions and movements on top of the rotating piece, we used the arm concept from drawing machine #2 so it would only have one other movement besides rotating in a circle. There are also some smaller changes we made to strengthen the cardboard, including making the handles and some staffs rolled up pieces of cardboard and making the main body piece of the rotating structure one large, continuous piece of cardboard.

After using the machine, we went over the marks with another layer of pen to see exactly what kind of pattern the machine made.

The structure and movement of this prototype were simpler and stronger than the original drawing machine #1. We also focused more on craft in order to try and make the gears and overall mechanism work more smoothly. One thing we noticed was that the placement of the gears was crucial. If the gears were placed too close together they would be too tightly squeezed and slowly come off the axis. On the other hand, if the gears were too far apart, they would touch and rotate properly. We felt that for this prototype, we were able to clean up the overall structure a lot, but the mark that was created was too simple and not interesting enough compared to the complexity of the machine.

Refinement #2

For this prototype we focused a lot on creating a more complicated mark. We wanted to create a movement very similar to that of drawing machine #1 minus to string pulling the pens inward. We found ways to simplify the wiggling mechanism; we used only two pens so the pen holder had more room for movement and we used only one arm to push and pull the pen holder.

We tried to use as little glue as possible; we used cardboard tabs to connect the two main body pieces, created a plus shaped staff to prevent the gear from turning, and rolled little rods as pivot points. We also created a sturdy platform for the bottom of the gear to keep it from wobbling around while turning.

The mark

This prototype still had some structural and craft issues — the gears and arms, being off center, caused the entire machine to tilt to one side. Also, the small pieces of cardboard, named the x-shaped rods wore down after multiple uses. We still had problems getting the gears to work continuously and to connect well.


For the final machine, we wanted to try a different way of creating the “wiggling” motion; we created a mechanism to flap the pens back and forth.

We used all the same techniques from previous prototypes to minimize glue use and create a sturdy machine — creating x rods, using rolled up pieces of cardboard instead of chopsticks as the turning axis for gears.

For the gears, we chose to fill the gaps in the corrugated cardboard with paper to make the gears stronger and less likely to be flattened.

Instead of the using the thick tabs of folded up cardboard, we create tiny cut out, hook tabs. We found that this way was much tighter and also kept the two cardboard pieces from being crushed, worn down and weakened when being connected together. We also used many bi fold pins as sort of bumpers on each end of the rods to prevent the gears and arms and various parts from sliding off. Lastly, we reinforced a lot of the cardboard parts by creating double layered parts.

The mark is dark and clear. The wiggling motion creates a flower/star pattern in the circle.

Machine’s mark

The entire machine can also be disassembled into smaller parts.


During the process of building this project, my partner and I had a number of obstacles and creative blocks. Although we were able to create a final product, there are some things that I believe can still be changed or that I would do differently. For starters, I believe that our product strayed from the prompt of the assignment. For this assignment, I believe it was important to consider the mark of the mechanism and the movement. My partner and I did explore a few different marks and movements, but we got hooked on the idea of using gears and on our first prototype. Instead of focusing on things like making the material happy or exploring various simple devices, we focused a lot on refining on original prototype. We focused so much on creating a mechanism that worked smoothly that we overcomplicated our device.

Also, working with a partner was a challenge. We often had differing opinions and ideas that would make it difficult to progress and move on with the assignment. At the same time, these “arguments” ad debates, I believe, helped us develop and create a well thought out final device. By working with a partner, I was introduced to different takes on the assignment and different views on how to make a mechanism and/or mark. We both brought a variety of ideas to the table and had differing specialties and skills, which was very beneficial throughout the process of creating a device.

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