Compound Machine Project
Define the Problem
Gantt Chart
Evaluate the Solution
We started off this project with a design brief so we could understand what we would be doing. We learned that we had to build a compound machine that would be able to shut a laptop. We had vex parts available to us and a time constraint of four days. We brainstormed three different machines which are shown above in our beginning sketches. We decided to take and run with the idea that we would have a pulley system with string attached to a series of gears. In theory, once that string was pulled the gears would spin which would move a lever attached to the output gear down and shut the laptop. We were expecting enough torque to be able to shut the laptop. Once we assembled the machine, we realized that the pulley system was not strong enough and the gears would not move. The teeth on the gears were also not catching when ever they did move. So by this time it was time for our project to be done and it did not work. Luckily we were granted another day of work. We made a couple of minor changes which improved the machine a lot. We took away the pulley system since it was not working and just added a crank to the back of the axle which was attached to the input gear. We also changed up the gears to gears with more teeth, and finally we added a wheel and axle onto the end of the lever which was able to more smoothly shut the laptop while adding more weight. So overall our compound machine ended up working at was able to complete the task. We worked together as a team to finish this project when the time was scarce and were able to finish. We did go with Shea and John's idea also with a few slight changes.
We started off this project with a design brief so we could understand what we would be doing. We learned that we had to build a compound machine that would be able to shut a laptop. We had vex parts available to us and a time constraint of four days. We brainstormed three different machines which are shown above in our beginning sketches. We decided to take and run with the idea that we would have a pulley system with string attached to a series of gears. In theory, once that string was pulled the gears would spin which would move a lever attached to the output gear down and shut the laptop. We were expecting enough torque to be able to shut the laptop. Once we assembled the machine, we realized that the pulley system was not strong enough and the gears would not move. The teeth on the gears were also not catching when ever they did move. So by this time it was time for our project to be done and it did not work. Luckily we were granted another day of work. We made a couple of minor changes which improved the machine a lot. We took away the pulley system since it was not working and just added a crank to the back of the axle which was attached to the input gear. We also changed up the gears to gears with more teeth, and finally we added a wheel and axle onto the end of the lever which was able to more smoothly shut the laptop while adding more weight. So overall our compound machine ended up working at was able to complete the task. We worked together as a team to finish this project when the time was scarce and were able to finish. We did go with Shea and John's idea also with a few slight changes.
For which mechanism was it easiest to determine the M.A/Drive Ratio?
The gear train was easiest to determine the drive ratio.
For which mechanism was it most difficult?
The crank or wheel and axle was the hardest
At which value would you estimate the input and output forces of your compound machine? How did you arrive at this?
The output force would be about .7 of the input force. Multiply the IMAs of all 3 machines .
What modification could you make?
Use more metal parts and make the overall machine more stable.
The gear train was easiest to determine the drive ratio.
For which mechanism was it most difficult?
The crank or wheel and axle was the hardest
At which value would you estimate the input and output forces of your compound machine? How did you arrive at this?
The output force would be about .7 of the input force. Multiply the IMAs of all 3 machines .
What modification could you make?
Use more metal parts and make the overall machine more stable.