A question from Jeff H.
Subject: windmill retrofit
I was curious about retrofitting old Aeromotor windmills with a belt reduction to a commonly available truck alternator. With the advent of serpentine belts, it sounds that much more possible. My old 2003 Chevy duramax diesel truck had a serpentine belt perimeter of appx 11.5 ‘. My question is; could the 20″spacer ring of the old Dayton rear truck wheels be machined and modified and attached to the fan for that purpose. It’s otherwise impossible to find a serpentine pulley that large. Any thoughts on that would be appreciated.
It’s rather amazing what Engineers of the past were able to do with so little wind energy. I think that’s the case with the old Aeromotors…. lifting the cover off that gear rack, and studying the simple but elegant method to drive the sucker rod is a delight.
I think your first goal should be to identify how much electrical power you would need to generate in order to be happy with your effort, and then another important study might be what the folks of the day did to make electrical power.
How many brands of electrical wind chargers were there? RCA, Zenith, and Winco for Three. If you study their design, they’re all direct drive units that operate at higher RPM, and hopefully deliver enough energy to power a radio.
My first thought is IF there was an easy way for Aeromotor to have gone after that business of selling wind chargers with their existing fans, they would have done so, but I would imagine their fan was optimized to drive that sucker rod via a reduction box to start work in lower winds with low energy, they knew a Rancher needed water not bragging rights that his outfit pumped the most during a storm..
Consider that the Aeromotor fan was designed to drive through a reduction box and driving a sucker rod whose mass was often ‘countered’ with a weight set up by the Erector to assure that every grain of energy went into lifting water. You’d be taking a fan tuned for a specific chore and adding a speed increaser to drive your Generator. I have seen such things, but why did all the popular wind chargers of the day go direct drive?
But here’s a more specific reality for you.. a typical truck alternator is quite inefficient, some are able to convert about half the mechanical energy that is put into the generator shaft into electrical energy, others are a bit better, but as I see it.. you are attempting to mate a tiny source of power with a device that was engineered to survive under the hood of a truck, in high heat, produce energy required over a wide range of RPMs, and to be made quickly and cheaply. Perhaps one of the last priorities of the design is efficiency.
Fabricating your very large pulley is a job for sure, some experimenters have used a bicycle rim in the past, and some have even used tiny cable instead of belts.
I think if you define your ‘power’ expectations, and then attempt to calculate the power potential of the beautiful and simple Aeromotor fan, you’ll find a miss match, and decide to invest your time with the more popular designs.
Here’s my advice: The Aeromotor fan is a thing of beauty, leave it unmolested, maybe put it up for sale? Look up Hugh Piggott, (a must read)… visit the website “otherpower.com” and study some of their easy to build wind turbine designs. You’ll likely have fun, and the learning never ends.
So.. you now have my unprofessional advice, but don’t forget to study your property and determine if there’s ever enough wind potential to merit your efforts to capture a bit of it..
Oh yes.. you knew I’d get this in.. didn’t you? And Jeff, I don’t claim you are afflicted.. only a warning to you. The Gang Green Mind has no patience for figuring.. if they see a breeze come through that causes the leaves in a tree to move, their minds often envision a whirly gig making power equal to what the power company delivers….. everything is simple in their minds. For the rest of us, it’s best we learn how to measure before we build, and our Carpenter Friends warn us.. measure twice before you cut!
All the best….