Its the end of the semester and my engineering (mechanical) semester long project is due. The task is to build a machine to lift as heavy a weight as possible (starting off with 1.25Kg weight) a distance of .25m. I have attatched my plan to do this using pulleys and a wood structure (only allowed wood, pulleys, nails and screws, and an oil lubricant). My question is, in order to lift an object, how does pulley size affect the lifting force? what about the amount of pulleys or how many times its wrapped around a pulley? Since its a competition, i think i have a pretty good chance in these runnings, but what do you guys think? anything you would change? Finally, the most important question, home depot and no where really online has these pulleys, where do you think i could get my hands on some cheap pulleys say 1-3 inch diameter?