Looking to do a little educational project with mini wind turbine & new 3D printer

jdlev

Hi Guys,

I'm new to the board, and had a few quick questions. Just got the Makergear M2 3D printer, and I don't think it's been idle whenever I've been awake lol. I've already printed the props & hub for a mini wind turbine. I know it's not ideal, but I plan to hook it up to a little tiny motor to see if I can generate a 300-500 millivolts. When I hand spun it, I was able to get it up to about 700 millivolts on my voltmeter.

Anyways...just looking at this as an educational project because I've always been fascinated with green energy. The wing span is only about 8" in diameter. My main question is what to do with this little, meager source of power lol. I'd like to capture it if possible. I plan on using a spur and pinion gear to help increase the velocity the motor spins at. I have a bunch of old RC batteries that are classifed as 3800mAh, 7.4v batteries. Could you just hook the +/- leads up to the battery and charge the battery (albeit very slowly lol).

Based on how I do with this one, I was planning on scaling up. Is there a defacto standard for a typical generator/motor used in wind turbines that has a wing span of say 2-3'? Also, does anyone know of any good schematics for printing a turbine about that size?

Thanks

JoshK

Very cool. I actually have a set of tiny bearings sitting right beside me now that I intended to use for a 3D Printed wind turbine just like you mentioned. My goal is to just put it on my deck. It will have a good LED light. Either the light will just work when the wind blows after dark, or it will charge a small battery, then come on after dark. It would just be a fun decoration. Maybe that could be your goal too? I haven't got time to pick out the motor to design around though. The main enemies of this project will be the mass of the small blades (hard starting) and dealing with the low RPMs (mini gear box?). I would recommend printing each blade to 8" for a larger turbine to allow yourself some extra power.

BB.

Remember that the voltage source needs to be higher than the battery voltage + blocking diode drop (almost 4 volts + 1 volt diode drop). 700 mVolts is not going to charge any standard battery type.

-Bill

jdlev

BB. wrote: »

Remember that the voltage source needs to be higher than the battery voltage + blocking diode drop (almost 4 volts + 1 volt diode drop). 700 mVolts is not going to charge any standard battery type.

-Bill

I'm not sure what you mean by a blocking diode? I know a diode basically allows electricity to only flow in one direction, but beyond that, I'm not sure what the purpose of a blocking diode is. So since I'm in the mV range...I guess I need to go bigger, and maybe just hook up a little led to this practice run rather than trying to store any power, huh?

BB.

It depends on what is charging--But if a generator (brush type), you need a blocking diode to prevent energy going backwards and making the generator become a motor+fan blades.

If the generator is actually an alternator, you need a rectifier assembly (up to 6 diodes) to change the AC output of the alternator into DC current.

-Bill

JoshK

This is where the motor becomes important. A motor that has RPMs applied to it becomes a generator. But you need a gearbox to get the RPMs high enough to get the voltage up. An LED can be connected direct to the motor, as long as you add a little protection to stay under the LEDs max voltage (1.2v for example). This is crude, but if you want to start somewhere, it's a good start. A destroyed LED will only set you back 9 cents or so if you get a cheap one.