Nifty Lifty Machine Mike Yang & Jack Yang

Initial Design This is the first group design that we agreed upon. It features an inclined plane with a block and tackle pulley that's attached to two wheel and axles and a fixed pulley.

Materials We spent the first weekend working on our Nifty Lifty machine gathering the materials we would need to build it. List of materials: Cardboard String Tape Tape dispensers (x2) Nails Paper cup

Building the Machine The following two weekends were spent building the parts that made up our design. Some key components include the inclined plane, two wheel and axles, and one additional pulley (our design consisted of three pulleys, but we were only given two).

Inclined Plane The inclinded plane was made from cardboard. It was built by cutting a cardboard box into two triangular halves, and attaching them together to form a ramp. It has a length of 33cm and a height of 15cm. The ideal mechanical advantage of our inclined plane is: Length/Height 33/15 = 2.2

Wheel and Axle Each wheel and axle was created using cardboard, a tape dispenser (wheel), and a nail (axle). We used multiple layers of cardboard to keep the nail in place. The cardboard was inserted into the side of a tape dispenser to form a functional wheel and axle. The mechanical advantage of each wheel and axle is: Radius of wheel/Radius of axle 2/0.15 = 13.33

Pulley With the two pulleys we were given, we created a block and tackle pulley. The ideal mechanical advantage of the block and tackle pulley is 3. We created our third pulley using cardboard and a paper cup. The wheel was made by cutting out the bottom of the paper cup and gluing a pieces of cardboard on either side. The ideal mechanical advantage of the fixed pulley is 1.

Mechanical Advantage The ideal mechanical advantage of our entire machine would be: 2.2 x 2(13.33) x 1 x 3 = 2.2 x x 1 x 3 = Our machine, if completed, would achieve a ridiculously high mechanical advantage. Even if we were to factor in the amount of friction, it would still be able to generate an incredible amount of force. However, as we soon discovered, our design was, perhaps, slightly too ambitious.

Issues We completed the first portion of our machine, which consisted of a block and tackle pulley attached to an inclined plane. However, in order to proceed, we were required to set up a system of two wheel and axles (already built), which would be rotated by a rope tied to the input weight. After thinking it over, we scrapped the latter half of our machine due to construction complications and lack of sufficient material. We also encountered difficulties in choosing the right type of string to operate the block and tackle pulley. Thin strings moved smoothly, but often slipped off the side of the wheel. Thicker strings stayed in place, but the friction between the string sections restricted movement to a certain extent.

Second Design Our second design consists of just two simple machines: an inclined plane and a block and tackle pulley. The input weight would pull on the pulley, and the attached output weight would be drawn up the inclined plane. Both simple machines featured in this design can found in our initial design.

Issues The overall structure of our second machine weak. The stand we attached our block and tackle pulley to could not carry the weight of 600 grams without bending over. We fortified the stand with pieces of cardboard, but this proved to be ineffective. We also experienced problems with the friction of the inclined plane. Since we are pulling the 600 grams directly up the slope of the incline, the weight had to overcome a considerable amount of friction force to move up our inclined plane. Our machine would need achieve a greater mechanical advantage to lift that weight. A toy car, or anything small enough with wheels, for that matter, would reduce the amount of friction on the inclined plane because its wheels can convert the sliding friction of the weight into rolling friction (which is easier to overcome). But since we do not possess one, we would need to find some other method to reduce that friction.

Revisions Eventually, we decided to rebuild the entire machine using material that was more sturdy. It was suggested to us that we could loop the string around the block and tackle pulley multiple times to achieve a higher (ideal) mechanical advantage. This, however, would increase the input distance, as well as friction between moving parts. In the end, we decided to leave the block and tackle pulley as it is, chiefly due to the fact that the input distance was simply too great. We did, however, lower the height of our inclined plane by 5 centimeters (it is now 10cm, making the mechanical advantage 33/10 = 3.3) to reduce the amount of force required to pull an object up it. We also thought to wrap two strings around the output weight, so that when it is pulled, the strings would unwrap, allowing the weight to move in the manner of a wheel. This way, the friction between the weight and the ramp would be converted to rolling friction, and less force would be required to lift the weight.

Mechanical Advantage The ideal mechanical advantage of our entire machine would be: 3.3 x 4 = 13.2 After making revisions, we found that an input weight of 100g (1 newton) was required to lift the output weight of 600g (6 newtons). The actual mechanical advantage of our entire machine would be: 600/100 = 6 The mechanical advantage of our second machine was quite a bit lower than that described in our first. We were able to compensate somewhat for what was scrapped in our initial design by using the materials to our advantage, but this diminished our machine to a very basic compound machine. However, construction of this machine was within the range of our abilities, and keeping it as simple as possible will also reduce friction.