# Pendulum Wave Machine

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## Introduction: Pendulum Wave Machine

This pendulum wave was a project for my grade 12 portfolio class. It was a self led assignment, so we were allowed to make a piece of our own choice. I had seen videos of pendulum waves before, and we were studying pendulum movement in physics, so I decided that this would be an interesting project.

I made the design to use two of my favourite materials, metal and wood. The wood for the beam and the base, along with the eyelets can be purchased at Home Depot. The heavy thread and maple spheres were from Michael's.

This project took about 10 hours to complete, and the cost was under \$50.

[I've included some videos of it in action in the conclusion]

## Step 5: Step 7

I figured out the lengths of the pendulums after having built the frame, which is probably backwards. You would be best off creating your pendulum lengths before making the frame so that you can build the frame to fit them exactly.

This is the calculator that I used to pick all of my pendulum lengths, credit to Paul Liu at hippomath.blogspot.ca for creating it: CALCULATOR (you can pick number of pendulums and set limits for sizes, super helpful)

## Step 6: Conclusion

Overall, building the pendulum wave went by very quickly. The longest part was probably stringing the pendulums up, because you have to be very specific about their length and avoid any twisting.

The result is a lot of fun to play around with. It goes through about 2.5 cycles before it gets out of sync. Because I didn't build my frame as a curve for compensation, the pendulums sit on an arc. I really enjoy the way it turned out, if I were to do it again I would probably make it a bit smaller so it could sit on my desk.

## Recommendations

• ### PVC Class

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## 12 Discussions

Thanks, they were fun to come up with after the fact! I usually forget to take pictures of my projects while I am building them.

Wow very nice instructable. I will make one for myself and a mini model for my science teacher. I bet she will love it.

Nice build, love the aesthetic! I made one of these a couple of years ago. It kept a good sync for 5+ minutes. The key in achieving this is very precise adjustment of string lengths and using string that is completely inelastic, and note made from tangled fibers. Secondly using heavier weights reduces the effect of drag.
To achieve this I used guitar pegs, metal wire. As weight I used heavy, big ball bearings. The ball bearings are also very uniform in both shape and weigth. (these adjustments will make the setup more costly ofcourse)

For physics guru's: among others, this setup allows you to show the limits of a simple pendulum model. Perfect lengths can be calculated by intoducing a good model for drag.