Design Journal - Day 2

November 13, 2018 

Day 2 Journal 

By: Lee Joshua Millora 

Today we went to Mr. Saporana, the woodworking teacher in St. Patrick Catholic Secondary School, to ask for some scrap wood for the launcher and the base. We chose to get wood for only the launcher because the wood meant for the base was crooked, which would affect the velocity of the ball and direction of it. We continued to examine the scrap wood to see if they are crooked or have any holes since it would be a systematic error that might affect the physics calculations for the launcher. The sizes, types, and thickness of the woods are important to make a strong and sturdy launcher. It was hard to find the woods for the base and launcher because some of them have holes, glued, or uneven.
          
          On the day 1, there was a problem that needed to be fixed on the launcher. The problem was that the spring moved, which it should not do because that could affect the physics calculations behind our toy like the spring constant. We have come up with two solutions:

          After visiting Mr. Saponara's woodworking class, we used the subway to go to Home Depot, but we ended up going to Canadian Tire, since we could not find Home Depot in the area we went. At Canadian Tire store, we bought two 3/8 carriage bolts and two 3/8 hex nuts. One carriage bolt cost $2.99 and one washer cost 25 cents. We first came up with one solution which was a hex nut to replace the wooden block that compresses the spring, and use the hex nut on the wood dowel, but the hex nut could not go on. To resolve this, we decided to use a metal carriage bolt to serve as two metal dowels since it would allow the hex nut to be screw onto the metal dowel. The dowel has to be metal because the washer is needed to tighten up close to the spring so that it does not move.

              Angel also came up with a second solution to keep the spring in place. At home, she realized that if she puts sets the dowel to its full length by pushing the dowel all the way into the hole, then place the wood block at the end of the spring, it would prevent the spring from moving. This can be seen in the video down below.

In the end, we decided to go with the metal dowels because metal is much more stronger than the wood. Since we might have different types of mass, the metal dowels ensure that even if the ball has a big mass, the metal dowels would not break under the pressure, as they are launching the ball. Since the heavier the mass, the bigger the force applied needs to be by pulling and releasing the dowel in the launcher. This is a milestone because the problem with the launcher was fixed and that we got wood for the launcher.