Awhile back, I received a K'nex set that utilized a pump and a motor in order to propel a car for a short period of time. I thought that this was the perfect fit for this project because we need short, fast spurts in order to propel the swings back and forth.
Here's another view of it. After you pump it to full capacity, the energy can be released by way of nudging the grey wheel. After that, the more you pump it, the faster it will go. The pump's motor also allows the swing to swing backwards, and that was vital to the swing's functionality.
The pump's motor drove the pulley system as seen above. The conveyor itself is a highly tensioned rubber band, which causes extreme energy loss on the swing back.
The pulley system was then attached to these two gears. This would increase the torque output of the pump's motor so that it could lift the swing all the way up. Or, at least, that was the theory. The pump motor could barely spin the pulley, and would not have been powerful to utilize in the full swing configuration. I then decided to scrap this idea, and go to a more powerful "Plan B."
The base, however, was really the only thing that worked in my first attempt, primarily because it remains static. I added queue gates that work via the knob shown towards the bottom of the photo. And if you look closely, you can see K'nex rubber tires that help keep the base from moving back and forth (by increasing the coefficient of friction
) due to the swinging nature of this flat ride. This portion of the ride works exceptionally well, but then I had to try to redesign the drive system of the swings, which turned out to be a headache of its own.
The new drive system that I proposed seemed like a simple solution to the power problem of my last attempt. The theory was that the motor was connected to a tire / wheel. The tire-motor system was on a lever so that when the lever was pushed down at the right end, the tire would make contact with the grey wheel, therefore driving the entire system. and when the lever was not pushed, the system would allow it to swing back naturally.
In the end, I decided to go with both of the wheels being tires, that way I had the most grip with less slip.
Now flash-forward to the completion of my first attempt. I ended up changing the gear system at the top (with doing a smaller red gear instead of a larger yellow gear) to make it faster and therefore seem more natural in its swinging. It also includes a double pulley system that allows for less slip pushing the car up, but seriously hinders the sing's ability to swing back. For instance, if the swing starts at the full height possible (120* of arc), it may swing back to only 30* of arc, which is pretty serious energy loss.
This picture showcases how I got the separate swings to swing equal, but opposite directions. The central yellow gear changes the direction of motion that the left swing has.
Here is a good look at the seats for the left swing. It is relatively heavy, which hinders the amount that the swing can arc (it can only go 80* of rotation). However, if the swing were any lighter, the swing would lose so much energy on the way back that it would stop its swing back at the bottom, once again due to the tensioned pulley system.
Here's one last look at VERSION 1 of this project. The main issues with this version include the energy losses on the swing back, and the motor's inability to propel the swing to a full arc of 120* like the full ride. If I can somehow fix these issues, then I think I'd be in good shape.
Just incase I didn't explain the issues I've encountered for your understanding, here is a video of me explaining and showing you where the trouble spots are:
https://www.youtube.com/watch?v=_ytfMI6dimo
I am not afraid to redo the entire thing and start over, so any suggestions you can make about how to make this swing fully functional would be appreciated. Since I am not completely happy with the first result, I will most likely redo it anyways haha.
Thank you so much and your feedback will be taken into account in the next Version.
So, I decided to make a K'nex model of basically that swing ride. Here are some updates:
Great job.
