CAM-imal! CAM Elephant

In this project you will learn the basics of how to make a cam model and how it works, more importantly have fun whilst learning.

- Corrugated cardboard
- Dowel (5mm)
- PVA Glue / Superglue
- Coloured paper
- Scalpel
- Scissor
- Compass
- Ruler and pencil
- Cutting board

Cam mechanism is composed of three basic components, cam, follower and a member. Member turns the cam and the follower swings in a linear motion. A cam is usually a circular or a oval component which is connected by a follower which could be a roller follower or flat bottom follower. There are many types of cams and followers but in this project we will keep it simple to get a better understanding of cam mechanism.

Start by creating a drawing of what you want the final model to look like, consider how big you want the model to be. I decided to make a very simple cartoon elephant to move with a flat bottom follower. I planned the frame to be made in 3 different stages (stage 1, 2 and 3 check the overview plan)
Glue each component 1, 2 and 3 to their respective letters e.g.
Component 1 glue with 1A, 1B and 1C
Component 2 glue with 2A, 2B and 2C
Component 3 glue with 3A, 3B and 3C.
*Other components... 0 refers to the elephant, 4 for the handle on the member and 5 for the Cam.

I measured the frame in 3 main stages so it was easier for me to assemble later on. Each component has the given height * length * width (H*L*W), (* consider the material thickness for the Cardboard and dowel I used a 3mm thickness corrugated cardboard and a 5mm diameter dowel). Mark out Component 1, 2, 3 and 4 on cardboard (I labelled my component with numbers representing which part along with letters for each sides of all components). Use a scalpel to make clean cut for each components, make holes for the dowel where necessary. Sketch out the basic shape of an elephant, we can always use some 1 ply cardboard to make legs *4, ears *2 and tail.

I made component 5 an oval cam using a compass to draw a 50mm diameter on the cardboard mark the mid-point, from the circumference from the first circle edge draw a 25mm circle, follow the cam diagram above. I had a maximum displacement of 12.5mm which is the difference between the cam and the member, the more maximum displacement we have the quicker the follower moves in a linear action. Cut 3 cam out of cardboard and glue it together.

I used 3 dowels all have a 5mm dowel diameter, using some office paper I wrapped around the dowel joining to make a strong joint, using some super glue to create a strong bond.
Dowel 1 length is 95mm for the follower
Dowel 2 length is 80mm for the member
Dowel 3 length 35mm for the handle

I used a 95mm dowel 1 to make a follower, at the bottom of the dowel I used a flat cardboard to create a flat bottom follower, dowel 2, through the cam enforced with some glue.

I made component 4, with 40mm*10mm cardboard X4 to create a support for the member followed by dowel 3 with 35mm for the handle. I passed a Glue each component 1, 2 and 3 to their respective letters e.g.
Component 1 glue with 1A, 1B and 1C
Component 2 glue with 2A, 2B and 2C
Component 3 glue with 3A, 3B and 3C.
*Other components... 0 refers to the elephant, 4 for the handle on the member and 5 for the Cam.

Assemble Components 1, 2 and 3 with their respective number and letter, using glue and if necessary use some 1ply cardboard to create support for joints. Now would be the best time to assemble all components (0, 1, 2 and 3).

Any finishing touches? Maybe a little bit of grass using green coloured paper. To give the elephant a little dimension use complementary colour to give a nice feel, I went with pale pink and washed blue and gold paper to make *4 legs.

Now that you have made your very own cam model consider using more complex cam and follower to further develop the your understanding and create complicated projects. Maybe try other forms of cam and gears to create something unique. I tried using a completely different method similar to this projects linear motion but it did not end well due to a lack of support for the gears. My other fails during the project included the miscalculations of the material thickness.