This week the ME team was working on a power generator for their project which included a hand crank system. The team describes their process below:
We started by designing a simple hand-crank and trying to power a 25 watt light bulb with it [photo 1]. We were not generating enough power to light the bulb, so the light bulb just glowed (it didn’t light up fully). We determined that we need to spin the generator faster to get more power, so we went about modifying out crank to include a gear ratio. Adding a gear ratio means that spinning the crank handle one revolution will rotate the generator hub more than one revolution (2.4 revolutions, in this case). The next few photos show our group hard-at-work in the machine shop at OSU: Peter uses the band-saw to cut steel components [photo 2], Sam uses the sand-blaster to clean and texture parts [photo 3], and Ryan welds a shaft onto a sprocket [photo 4]. The new, modified hand crank is complete [photo 5], and our test with a voltmeter is successful [photo 6]! The new design generates about 21 volts, which is a significant improvement over the 12 volts we were able to achieve prior to the modifications. Next, we’ll be conducting more tests and modifications—after all, engineering is an iterative process!