I stopped trying to figure out the GTR & voltage of this DC Motor... Geezzzz... WIN BRAGGING RIGHTS!!!

[farmhand]

Ok guys, who can figure this out??

Windmill (0-80RPM)
Flywheel (170lbs)
Drive sprocket on Windmill shaft: 60T
Input sprocket on Midshaft: 16T
Output sprocket on Midshaft: 75T
Input sprocket on Generator: 25T

Generator:
90vdc Gearworks JM5-001 (4200RPM, 1.7HP)

I have sadly about all but given up trying to work the math on this to see what my output voltage will range. I can't make finish this weekend, but 8days from now it will be generating.

SO, if you want some bragging rights, feel free to work this out or make a best guess before March 7th :D

 

[BentleyJ]

The first RPM step up from windmill shaft to mid shaft is 3.75
second step up from midshaft to generator shaft is 3.00
Total RPM increase ratio is 6.75 so as the windmill operates from 0 to 80 RPM the generator operates from 0 to 540RPM. Although we have no idea how the windmill RPM is limited to 80 RPM or what the torque vs. wind speed is.

The generator seems to be a repurposed treadmill motor. To answer your your question we would need a 3D graph of output Volts vs. RPM vs. current.

 

[farmhand]

My best guess is primitive but....
I calculate the GTR to be a 1 to 11.25.
The 4200rpm 90v motor would divide into 0.0214v per rev...
The 0-80PRM windmill gears up to 0-900RPM on the motor...
The comes out to 0-19.2vdc output....
The ECO Max has an 11-100vDC input....
So I should be able to charge at >45RPM.....

But the mill normally averages about 20-30rpm throughout the day..... but we're gonna try anyways! I can always add another shaft for a change if need be.....

 

[farmhand]

The first RPM step up from windmill shaft to mid shaft is 3.75
second step up from midshaft to generator shaft is 3.00
Total RPM increase ratio is 6.75 so as the windmill operates from 0 to 80 RPM the generator operates from 0 to 540RPM. Although we have no idea how the windmill RPM is limited to 80 RPM or what the torque vs. wind speed is.

The generator seems to be a repurposed treadmill motor. To answer your your question we would need a 3D graph of output Volts vs. RPM vs. current.

Yes, it's a treadmill motor. An old college instructor a decade ago said treadmill motors are always the best for DIY windmills, and it was roadside free 8years later (it checks out).
The windmill limits 80rpm by some force we don't understand, drag on the blades? It only ever goes so fast, but 80RPM is quite scary to watch from the ground I assure you!!!

So as we don't have this graphing you need to calculate, what's your best guess?

 

[OzSolar]

The windmill limits 80rpm by some force we don't understand, drag on the blades?

That's one of the coolest things about the old water pumping windmills. (sorry I can't help on the gearing question)

As I understand it the old Aermotor et al style of water pumper have two self protection systems:

1) Normal Self Regulating: All of those blades are great for catching low wind speed but are terribly inefficient at higher wind speeds which means it simply can't go faster than a certain speed. 80 RPM's in your case.

2) Storms: At some point the pressure is too much and the entire rotor has to get out of the way so for storms they pivot about the center on thier a yaw. Below photo courtesy of Rock Ridge Windmills.

 

[farmhand]

That's one of the coolest things about the old water pumping windmills. (sorry I can't help on the gearing question)

As I understand it the old Aermotor et al style of water pumper have two self protection systems:

1) Normal Self Regulating: All of those blades are great for catching low wind speed but are terribly inefficient at higher wind speeds which means it simply can't go faster than a certain speed. 80 RPM's in your case.

2) Storms: At some point the pressure is too much and the entire rotor has to get out of the way so for storms they pivot about the center on thier a yaw. Below photo courtesy of Rock Ridge Windmills.

View attachment 136880

Sadly ours has no YAW axis. It is on a straight shaft via pillow block bearings, about 3' down from the top. 90% of the wind come from the east, it always has nice farm art appeal, and rebuilding the gearbox was $1200.... So it just takes the brute force of the winds.... which is again scary at full RPM. Sometimes at 60-70mph winds the top of the tower rotates/twists enough to see the blades YAW a few inches at the top.... but it hasn't come down in 8years...... run it till the wheels fall off they say.

You might as well take a guess at the voltage range :D

 

[Warpspeed]

Going on the previous figures...
Windmill 20 rpm, generator 225.6rpm = 4.83 volts
Windmill 30 rpm, generator 338.4 rpm = 7.245 volts
Windmill 80rpm, generator 900 rpm = 19.28 volts.

You will get considerably less than those voltages under electrical load.
And don't try to run it continuously at higher than the full load amps printed on the rating plate, whatever the rpm.

 

[farmhand]

Going on the previous figures...
Windmill 20 rpm, generator 225.6rpm = 4.83 volts
Windmill 30 rpm, generator 338.4 rpm = 7.245 volts
Windmill 80rpm, generator 900 rpm = 19.28 volts.

You will get considerably less than those voltages under electrical load.
And don't try to run it continuously at higher than the full load amps printed on the rating plate, whatever the rpm.

So the motor is a 1.7hp (1250w?), and the Eco caps off at 800w.
It's really looking like I will need another midshaft (75t to 25t) which would put me in a better range for the 11-100v input.... Another midshaft would cost another $80 and drop the motor closer to the ground. We will find out soon enough

 

[farmhand]

Well shite,
Climbing the tower today and had to shut this project down
The steel past 20' on this 1902-04' tower is pitted beyond most steel in the scrap pile. It's scary, ugly, and incredibly not safe to go climbing on, drill holes, adding weight, let alone adda good amount of drag to the massive free-spinning rotor.

Plus with all parts I'm nearly up to $300 without the motor, and another projected midshaft will be right under 100.....


So I'm just going to see about designed windmill, which won't be anything near as fun.... but we're on top a good hill so it will do better than most of them....


Peace & thanks for the input.

Decided to toss it on with the midshaft just for the hell of it, and once that rotor is turning it'd damn near lift you up on the chain. Yet slowwww RPM on the gearworks..... but damn this should work somehow... Need to find a 2nd hand low RPM motor.....

 

[farmhand]

Goanna try one of these out between the motor and Eco, might just work
HiLetgo LTC1871 DC-DC Step Up Booster Converter 3-35VDC to 3.5-35VDC With LED Voltmeter DC-DC Step Up Module Power Supply Voltage Regulator https://a.co/d/0dL3p44

 

[farmhand]

Saga Update:
So without wanting to have this old tower fall, I still decided just to toss the 30' chain on from the 60T mill shaft to the 25T motor.... In hopes of getting something using the above variable boost module.... I have an analog meter & as expected I get 0-4v at 0-7MPH.... This seemed to be an light-average day for wind.

But it's made it nearly a week and one day had MaJoR wind & the chain didn't blow off so.....

So I ordered this motor which I will toss on tomorrow. It's a 12vdc 2900RPM with a 10:1 gearbox. Will have to drill-press the 3/8's bore sprocket to 7/16.

Will compute:
Windmill -0-80RPM - 60T Sprocket
1:6
Gear Box Driven - 10T Sprocket - 0-480PRM
1:10
Gearbox 1:10 - 0-4800PRM

Motor is 241rev per volt (without knowing the curve for this motor)
SHOULD BE: 0v-19.9v output.

Put this to the 4-32v to 30v constant boost module, should generate enough voltage at 16RPM at the windmill rotor.

The rotor agerages 20-30rpm in a light-wind (7-10mph) day.

We will see......