Ideas on DIY swivel mount for windturbine on mast

[AdironDoc]

Ok guys, help me out here. I'm out of ideas. I have a PMA and a matched set of blades. It's ready to be mounted. I have a 34ft mast with guy wires that's 1 and 1/4" in diameter at the top. Nobody seems to sell any frame or mount for this configuration unless you buy the entire turbine kit.

I can rig something to mount the PMA/turbine to without much difficuly, even craft a vane. The rub is how to make that attach to the 1.25" pole top and rotate freely? I've seen one that used a swivelling caster mounted upside down. Wheel was taken out and a pin put through the pole. The top screwed to a plate that held the PMA/blade unit. I was searching for other options, such as any household stuff that has a set of bearings, i.e. TV swivel (too wide), lazy suzan (too wide and weak), shopping cart caster (hard to find and doesn't have a hole in the middle to allow wires through the shaft). I have a 10 speed bike I could cut the neck out of but other than strapping it alongside the top of the mast, I'm not sure how I'd mount it.

Any thoughts gang?

Ideally, something like this..

[JRR]

Have you considered having the mast rigid all the way up, and the turbine rigidly mounted ... then have the mast rotate only at the mast-base?  I had this arrangement on a tv antennae mast once.  The guy wires were attached to flat rings (available) that allowed the mast to turn inside.

[AdironDoc]

That's an interesting thought and I hadn't considered it. Unfortunately, with the mast weighing over 50lbs, and the PMA/Rotor/Blades an additional 19lbs, not including wires, and downward pull of guys, it would prove harder to rotate at the base than atop the mast. Seems like whether the cylinder rotates at the top or bottom, I'd need a similar bearing setup? How did your antenna rotate? Was it a cylinder within a cylinder?

This is the best I've seen conceptually, but finding an "open center" caster is proving very difficult. Pop out the wheel, turn it upside down, maybe drill another couple holes for better purchase on the mast and viola! Someone who makes a simple and effective frame/mount is gonna find an empty niche and plenty of buyers.

[JRR]

I moved the mast manually to select which tower I wanted to recieve ... it wasn't moved often.  Do you expect the wind to shift often? 

The total weight you are taking about doesn't sound like that much to me. If the mast were mostly stationary, I see no need for a complicated lower bearing assembly .... plus it's there where you can maintain it.  I see the mast resting on a stack of large metal washers ... guided by a vertical pin.

Will the turbine assembly have a "wind rudder"?  Then why not let the top of the mast "free-wheel", guided by the wind ... but over a limited angle, say 10 degrees.  The turbine would follow the wind to stay effective .... you could major corrections, or take it totally out of service, by twisting the mast bottom.

[MountainDon]

I do not know a lot about wind power generation.  One thing I seem to remember though is that not all permanent magnet motors/alternators have bearings that accept much thrust. The forces of the wind on the blades with not only impart rotary motion, there is also a vector inline with the shaft. Pushing or pulling on the shaft.  Not sure how right that is but sounds like worth checking before assembly. Don't ask me how.

That's about it for what I know about the hardware.


Do you have the ability to do any machining? Or know someone who can?  WindBlue has an interesting mount.

[glenn kangiser]

Some use something like a trailer hub and bearings and let the wires run down the outside of the mast with plugs (welding cable plugs) at the bottom so they can occasionally unwrap it - I read that it would not get tangled that bad that often due to wind changes.  I haven't tried this and it would not be my first choice but it may work.

Mine (Bergey) uses slip rings for the contacts and a trailer spindle (Timken) type mount.  How about a four wheel drive spindle less the axel?

[glenn kangiser]

Another thought-- Pillow or flange block bearings.  Disc harrow bearings are heavy duty and hollow center in square or round configuration.  Farm supply stores stock them.

http://www.thebigbearingstore.com/discharrowbearing.html

[glenn kangiser]

or Go-Kart

http://www.northerntool.com/shop/tools/product_35764_35764?cm_ven=Aggregates&cm_cat=Google&cm_pla=Go-Karts%2C%20Electric%20Bikes%20%2B%20Scooters%3EGo-Kart%20%2B%20Mini-Bike%20Accessories&cm_ite=13803?ci_src=14110944&ci_sku=13803

You would have to fabricate the rest of the mounts but it shouldn't be too bad.

[diyfrank]

What is your plan for keeping the wires from winding into a knot?

I would go a little more on the heavy duty side or you may be picking up piece if the wind blows hard.
For what you are doing a flange bearing would provide a good swivel.

[AdironDoc]

Learning from what others have noted, I've coupled a good PMA almost identical to the WindBlue to a set of 5 WindGrabber blades rated at 70MPH. 12V at 150RPM, typically 300RPM in 6-8MPH. Others have noted twisting of wires hasn't been an issue when they used braided, heavy car battery gauge wire, wound in two opposing spirals down at least the top most part of the mast. Flexible enough to let the unit rotate 180 degrees, stiff enough to pull it back into position when the winds dip. If they do twist, I will need to put in a slip ring available at wind sites.

Wind vane will be aircraft aluminum set on a L-bracket. I will hinge it up and back to allow for furling at wind speeds exceeding 30-40MPH. Hopefully I'll learn to weld better by the time I put that together! Dump load will be 300W inline resistor. Inherent in the 5 blade designs is more torque with lower wind speeds, but lower RPM's overall due to wind drag compared with 3 blade designs, so I'm not so sure how likely a "runaway" turbine is.

Although my land is a few miles from a huge wind farming project and one of the windiest areas of New York State, I'm in deep forest and haven't noticed a great deal of wind. I'll put the unit atop a 60ft ridge and clear the trees up the side of the hill.

Thanks for the Windblue link, Don. Thanks for the advice Glenn and DIY, and the rest of you guys.

Doc

[glenn kangiser]

#0 feet above the tops of the near  highest trees or obstacles, Doc is the Bergey recommendation, but 85 to 100 feet total is better.

About 3 times the wind up there due to less surface friction turbulence.  Looking forward to seeing your progress.

[AdironDoc]

Thanks, Glenn. You know how many times I've completely changed a plan and avoided a blunder? I rely on the combined wisdom of those that have "walked the walk" before me. I've already learned a great deal here.

I wish I could get up to 100ft. Problem is, even though my place is on 30 wooded acres, the fine 60ft ridge that rises above the river valley is very close to the property line of two cabin lots. Not sure what permits, if any, I'd need for this backwoods project, but if my rig towers over someone's cabin, I'm sure I'll find out quickly!   I thought I'd clear the ridge on my side, and be at least 30ft above any obstructions, but still not visible from the other lots.

Since the 34ft mast ships by UPS, it ended up fairly cheap and will be my first foray into this stuff. If it seems to hold promise, I'll buy the 60ft telescoping and mount it on a 10ft galvanized length anchored in the ground. It's a reasonable $189, but is nearly $200 in shipping due to it's length!

I'll post some pics as I get this thing together. Your bearing links are great. I'll be ordering a set as I get some practice on my welder and cobble together something that looks like the photo Don linked to.

Cheers,
Doc

[AdironDoc]

Well, here's where I'm in the dark about my solar and wind ideas. Solar panels, microhydro, wind and the like all put out varying voltages and amperes at any given time. I'm assuming a charge controller will make that output acceptable, and is specific to a given voltage such as my 12V array. What's the highest voltage used to charge heavily discharged batteries? Will a charge controller work with my solar and wind simultaneously? Are there other things I will need between the panel/turbine and batteries other than controller and diode?

[MountainDon]

Each input type requires its own charge controller.

A wind generator controller needs to have a dump circuit. When the batteries are full this is needed to prevent the turbine generator from destroying itself. The dump load can be a water heater or air heater made for the low voltage.

A PV module charge controller must be able to handle the maximum voltage, Voc, that the panels might produce on the coldest morning when the first first strikes the panels. This can be a high spike and can be enough to burn out the controller if the controllers max voltage rating is too low. This is especially important to match correctly when using modules in series. No dump load required for PV.  Store bought PV modules have all the diodes built in, no need for extras.

A PV module that is called a "12 volt" module will have a maximum power voltage, Vmp, of around 17 to 18 volts. More is okay if the charge controller can handle it. Less is not. Actual charge voltage at the batteries will vary up to about 15 volts.

A wind generator and an array of PV modules, both with their own controllers, can be used simultaneously.

Fuses or circuit breakers are required. Some charge controllers need the ability to be isolated from the source and the batteries for setup. A circuit breaker before and after the charge controller makes that easy.

DC circuit breakers are not the same as AC breakers, BTW. DC fuses have different characteristics from AC fuses as well.