Encourage students to experiment with sketching enlarged views and cut-away views to show parts that are very small or obscured by other parts. Leonardo often left out the casing and structure surrounding machines in his illustrations so he could show the workings more clearly. What is the function of this gadget? How many moving parts does it have? How are the moving parts connected to each other? What does each moving part do in the gadget? Which parts are simple machines?
Ask students to get their parents involved in helping them locate examples of machine diagrams from home. The instructions provided by manufacturers with bicycles, kitchen appliances, tools, and lawn mowers often contain explanatory diagrams to help you understand these machines. Auto repair manuals also contain dozens of these diagrams. When you have several diagrams from different sources, ask the students to compare them and discuss them using the following questions as starting points:.
Leonardo's Machines Leonardo experimented with machines and made changes to improve how they worked. Text Block:. Wheel and Axle: A wheel or spoke is locked to a central axle so that when one is turned the other must turn.
A longer motion at the edge of the wheel is converted to a shorter more powerful motion at the axle. In reverse, a short powerful force at the axle will move the wheel's edge a greater distance.
Pulley: A single pulley simply reverses the direction of a force. When two or more pulleys are connected together, they permit a heavy load to be lifted with less force. The trade-off is that the end of the rope must move a greater distance than the load.
Wedge: A wedge converts motion in one direction into a splitting motion that acts at right angles to the blade. Nearly all cutting machines use the wedge. A gear is a wheel with teeth that mush together with other gears. Open Questions : What types of gears are there? There are lots of types of gears I will give a example spur gear, helical gear and many more! Pulleys are used for lifting easier objects What are gears use for? How many things does a pulley have on it?
All About Explorers-Opinion. Off The Wall Best Idea. Leave a Reply Cancel reply Your email address will not be published. Showing that several pulley wheels dispersed the weight more than a single pulley, he proved the formula mechanical advantage MA. MA is the number of rope sections that determines how much easier it is to lift or haul the object. This device consisted of huge beams that swung out. One version dropped weights to punch holes through invading ships to sink them.
Another made use of a claw to raise, shake or capsize a ship. Other early applications of pulleys in ancient warfare were crossbows and catapults among others. Though the robot did not survive to the present day, it appears that the device was capable of walking, sitting, and jaw movement through a system of pulleys and gears. He also incorporated some of the concepts in the design of planetary exploration robots for NASA.
Through the years, pulleys found their way to the dark side of history. Warfare and torture devices became all the more gruesome with the mechanisms involved. One such device is the strappado, mostly used to extract information from alleged heretics and witches. This device consisted of a pulley over a rope that passed over a beam or hook on the roof and was tied to the hands of the victim.
Additional weight could be added to the feet. The strappado dislocated joints and limbs causing long-term damage to nerves and muscles, and permanent paralysis and loss of sensation in the arms. Another torture device was the upright jerker. A cord was wrapped around the neck of the condemned who was positioned on a platform. Rather than dropping through a trap door, a system of weights and pulleys would jerk the victim into the air violently. It depends. So care must be taken to avoid getting fingers, loose clothing, and hair caught in its workings.
Also since pulleys are often used to lift heavy objects one should be careful. If the rope, cable, or hardware which mounts a pulley were to fail, serious injury could result if you happen to be under the load. One must be careful not to exceed the documented rating of lifting equipment. It is used to pull two things closer together. It can be used to lift heavy objects by pulling the heavy object closer to something above.
It is sometimes used as a trap. You can add or subtract pulleys from the system. More pulleys makes it easier to pull or they allow you to pull a heavier load , but you have to pull more rope to move the load by the same amount. Many different types of pulley systems exist. For an example, the average sailboat may have 3 or 4 different pulley systems boomvang, cunningham, outhaul, mainsheet , all doing different things.
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