Hello! I am in the beginning stages of designing a system that would drive a generator using gravity - similar to an old grandfather clock. I have a couple of questions about my assumptions/design that I am stuck on:(adsbygoogle = window.adsbygoogle || []).push({});

- I found a motor which is rated 6v-12v DC, 188 RPM @ 12V with no load, and a max no-load current of 0.53mA. Does this mean that if I were to drive the motor at 188 RPM, I would see 12V of output, with a max current draw of 0.53 mA?

- For my gear system right now I am calculating that in order to drive @ 188 RPM I will need to have a four gear system, with the 2nd and 3rd gears on the same shaft in order to step the gear ratio twice. Basically I am looking at this: Weight drives Gear 1 (100 Teeth), Gear 1 drives Gear 2 (16 teeth), Gear 2 is on the same shaft as Gear 3 (100 teeth) so they have the same rotational speed. Gear 3 drives Gear 4 (16 teeth) which is connected to the motor shaft to be driven at 188 RPM. In order to achieve the proper output and the drop rate that I want, I calculated the first gear needs to rotate at 0.5 RPM, which gives me a drop rate of 1.2 inches/min - or 6 feet over the course of an hour. What I am unsure of is how to calculate the weight that I need to get this rate! How would I go about calculating the friction/other forces in the system which will create an equilibrium with a certain weight at this drop rate?

Any help on either of these 2 items is much appreciated!

Thanks.

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# Weight Driven Generator Calculations

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