Our compound machine, consisting of mainly three different simple machines, is a crane designed to multiply your force in order to effectively and efficiently lift the four 75 keg up a steep hill. Our machine starts off with the gear train. As you rotate the handle, all the gears rotate along as well. Since we connected the rope of the pulley to our gears, it then puts the pulley system into action. We created movable pulleys throughout the arm until the tip to stabilize our rope and also give us a mechanical advantage.
At the top section of our arm we created a lever to support the load. This magnifies our effort force since a combination of all the mechanical energy is being carried out. With the pulley system, connected all the way to the gear train, and the lever working all together, our mechanical advantage is increased greatly. We created a series of gear trains to not only increase our advantage of torque in the machine but also to increase the mechanical advantage rather than losing efficiency due to friction and thermal energy. Doing this, we magnified our effort force onto the load.
Also, in the gears, we arranged it so that the input gear and the output gear eave us a low gear ratio and the idler gears in between. It also allows us to control the direction of our force in the machine. Since it is linked to the pulley, we can control the direction of the rope. However, it only restricts to move it up or down. In the arm of our crane, we created a lever in which we minimized the length of the load arm as much as possible to give us a greater mechanical advantage as well as act as a basic structure to support the pulleys.
So, not only did our levers serve for efficiency, it also serves for framing the shape of our model and holding/connecting it al together. We also found that a triangular support system was most effective in stabilizing our levers, so we created a triangular form using a connector piece with the two parts of the arm. It is evident that we prioritize pulleys throughout our model. Mainly because it provided range, for the steep hills, and also had a high mechanical advantage while doing so. We tried to utilize as many movable pulleys as possible because they gave a higher mechanical advantage with about the same friction.
Like the lever, it was multi-functional so we used it to our advantage. At first, we were hesitant to mainly use pulleys because of the abundance of friction that came along with it. But we decided, we could reduce friction using lubricants, such as grease and oil, or put ball bearings throughout our system. As you can see from our many designs we have faced many difficulties. In our first design, we wanted to incorporate a crane but with a ratable arm. However, we soon realized that with the lack of flexibility in the logo kits, it would be rather difficult.
So we decided to make a new design in which we created a crane with retractable arms. The foundation was much like our present design. But we found it was impossible to incorporate a pulley system while also having retractable arms. What we tried to prioritize most in this project was portability, so with each design we used as little equipment as possible (also to decrease the cost of the machine itself material-wise) thought of creating a forklift machine. However, we soon realized it was a steep hill we’d be driving up and carrying almost keg of weight (the four barrels combined) seemed impractical.
Another idea we had was to utilize triangular wheels to drive our aching since we noticed they worked best on uneven terrain even with the amount of friction that they used. We remember this being taught in many classes that the triangular structure was the strongest in providing support for structures. We also noticed that we not only wanted to lift the barrels, we wanted it to get safely to the ledge. Unlike many of the other machines we saw, our machine had to move up and down and side to side. What eventually happened was that we combined all of our previous designs into a new idea we created, which brought us to our current design.
Although we couldn’t use many of the aspects we wanted to such as the retractable arms, rotating pole to move side to side, and using a block and tackle pulley system but they were all hard to create when working with logos. We also wanted to incorporate simple machines not many other people considered such as the screw or inclined plane. We thought about making a platform that rotated around a pole all the way to the ditch. However, we realized it was impractical due to the danger of our plan, instability, cost of materials, and inflexibility.
When we realized we were using a to of friction throughout our system we thought of how to reduce it as much as possible. We decided we would put lubricants throughout our machine, such around the axles of the wheels to move smoother. Also we would put bearings all over the wheels and the pulley wheels to reduce the resistance to our motion in the machine. Lastly, we wanted to proportionate the effort and load by adding weights to the effort arm so that the heavy load doesn’t tip over the machine. Much of our other machine design basically flows along with the decisions we made about hanging the force where we wanted.
Though some of our other designs are better than this design they all failed to function due to our limited supplies received in the logo kits. If we had a larger variety of building materials our work would have been much more simpler. In the end, we faced many problems throughout the designs. However, they all led us to the finalizing product we have now. Although we missed many of the aspects that we wanted most in this machine to make it unique and efficient as possible, we still tried our best applying all that we know into this specific design.
