Sketch of Spinner After Redesigning
First, we wanted to see what the spinner would look like before we printed it. So, we made a 3D model with all of the weights and bearing to make sure we liked it before printing.
3D Model of What It Would Look Like
Moving on to Printing
We then changed our STL file to a Maker Bot file and plugged it into the printer to begin printing.
Printer We Used to Print Our Spinner
After our spinner was printed we added the 608zz bearing and all the weights which were 3/16, 3/8, and 9/16 ball bearings.
Spinner with Weights After Being Printed
To test our spinner we put it onto a skateboard truck screwed to a board with a 3D printed part and a nut holding it in place. We then lifted the arm until the back of it was flush with the wood and droped it on the edge of the spinner. We started the timer as soon as it started and when it completely stopped. We recorded the time of each of the three heights three times each.
Relationship Between Weight & Time
We found that there is a relationship between the weight of the spinner and the amount of time it spins. This relationship is limited because, if there is too much weight, then the arm can't make the spinner start fast enough. However, if there is not enough weight on the spinner, then the spinner will not be able to keep spinning for extended periods of time.
Relationship Between Number of Arms & Time
The number of spokes can have little or no effect on how long a spinner can spin. Rather, it is what is on the arms that makes the difference. If you were to give the spinner 20 arms, all of which with no weight on it, the spinner would not last for very long. However, if you were to make a spinner with 3 arms and .8 grams worth of weight on the arms in total and the weight is evenly distributed, then the spinner will last much longer. The number of arms of the spinner is much less important than the weight and balance of the spinner in general.
Relationship Between Height of Trial & Time
In theory there is a correlation between height of the trial and the amount of time the spinner will spin. Since, gravity is working longer on the arm so there would be more force. However, that is not what we found during the testing process. We found that the way our design caught the arm caused Tier 2, the middle tier, to have the most consistently long spin times, which lasted on average 3 minutes and 25 seconds on each spin. Tier 2 also had the longest spin, at 3 minutes and 40 seconds.