The Otherpower discussion board

Homebrewed Electricity => Wind => Topic started by: troutbum on October 01, 2017, 06:47:08 AM

Title: VAWT project
Post by: troutbum on October 01, 2017, 06:47:08 AM
Hi all!
I am in the process of building a VAWT. I have an old TV antenna to use as a mast and have secured a treadmill motor. I plan on building either the 3 or 6 vane blade system found open source on The motor I have is a Leeson DC PM motor (Data plate as follows: 5120RPM, 102 volts, 18.3 amps, 2 HP, 5.10HP peak). I am thinking of utilizing the existing grooved belt and pulleys for gearing.
I know that it is all relative with many factors; but what would be the optimum RPM to spin that motor for best output; what kind of gear ratio would I be dealing with to get that on an average day and what would I likely see for output power? Is that even a good choice for a motor, friends have suggested that the RPM is too high for this application? For low wind conditions, would the 3 vane be better than the 6?
I know that's a whole lot of questions in one post.
Thanks in advance
Title: Re: VAWT project
Post by: DamonHD on October 01, 2017, 09:20:19 AM
Is that TV antenna going to be strong enough to take the large wind loads that any sort of turbine implies?

(Sorry to fire back with a question: an adult will be along any moment to actually answer some of yours!)


Title: Re: VAWT project
Post by: troutbum on October 01, 2017, 10:05:58 AM
Damon, I really don't know as this will be my first full scale turbine. The antenna is one of those triangular tube ones with cross bracing. It seems quite sturdy and I plan on pouring a concrete base to hold it. The mast will only be going up about 10-15 feet as I live at the top of a slope with wind predominantly coming down the slope. Thanks
Title: Re: VAWT project
Post by: hiker on October 01, 2017, 10:38:19 AM
Rpms are high..a 220v motor would have been a better choise...I found a good source of treadmill motors at thrift shops..but if your stuck with will have a lot of drag to over a large 3 blader to over come drag and for speed as well...7 - 9ft  rotor diameter ?
Title: Re: VAWT project
Post by: troutbum on October 01, 2017, 02:06:44 PM
Thanks it was afraid that would be the case. 220v treadmills aren't very common here, except maybe the ones at the gym. Definitely haven't seen any for sale cheap or free. Maybe some more investigation is in order before I commit to this motor.
Title: Re: VAWT project
Post by: SparWeb on October 02, 2017, 02:24:55 AM
I think I agree the RPM is too high.  Consider if the voltage is linear down to 14 volts to charge a 12V battery, then:
5120/7.3=702 RPM -  that's still pretty fast.

Since VAWT's don't turn very fast, that leaves you with the gearing, but then the VAWT won't start turning on its own...  kinda chasing your tail...

Try a search on "Electronically Commutated Motor" or ECM for short.

They are used often in newer HVAC systems and there may be one driving the fan in your house's furnace.  No don't use that one! :P  But I mean you can look at it and see if something similar might be suitable for your project.  Several members of Fieldlines have put them to good use in small wind turbines and this might be ideal for yours.  The next problem, of course, is that there are a bazillion on e-bay and finding one that's right is possible but takes a bit of research, first.
Title: Re: VAWT project
Post by: SparWeb on October 02, 2017, 02:26:21 AM
Oh, yeah, and you don't actually have to buy a NEW one on e-bay, when furnace repairmen replace and throw out these things regularly.
Title: Re: VAWT project
Post by: electrondady1 on October 02, 2017, 07:06:57 AM
Ed Lenz ,windstuff ed was the originator of that design (Lenz2) . an early contributor to this forum.
nice idea to use the bike wheel as a pulley but the bike chain might be a bit noisy.
by 6 vanes you mean stacking another three blades on top?
i have no idea about the dc motor.
ed mostly built direct drive  8"dia. dual rotor axial flux alternators.
you can control the cut in speed.
 i find in a normal breeze they free wheel  up to the point they are loading the charging system.
establish your prevailing wind direction. check  the various corners of your house or buildings. you can sometimes find a place were the wind is amplified by structures.

Title: Re: VAWT project
Post by: MattM on October 02, 2017, 09:10:07 AM
I thought more blades on verticals based on Lenz drastically drops efficiency.  I know experimenting the rotations per minute certainly become noticeably smoother (it's a pulsating movement), but slower.  Never built one with a motor attached to know for sure.