Windmill Anchors

[Missourimiller]

I’m wanting to put up a small tower in the back yard with a 8’ mill on it. I want the mill to be just high enough the fan isn’t reachable from the ground. Instead on putting in legs below ground what’s everyone’s thought on these screw in anchors used for Mobil homes and such. My carport has 6 of them and it’s a 20’x25’ wind catch. My plan would be to box in the bottom on the tower all the way around then screw one of these in in each corner.

[LoTec]

Here's a photo of a six foot Aermotor on a 12' tower I put up every year for an exhibit at the Midwest Renewable Energy Fair in Custer, WI. I anchor it by driving in six 4' long rebar stakes, which is a lot of work. It has stood through several thunderstorms that were blowing away neighboring pop-up shelters.

But, this installation is only up for about three days a year.

boothmill.jpg

My thoughts on a permanent installation with screw in anchors: might work. But...
1. A six inch diameter auger plate is not a lot of surface to resist the lift created by a strong wind pushing on the top of a tower.
2.This looks like it is designed to resist lift; would it also support the downward thrusting weight of the tower & mill? How deep does the ground freeze where you live? How much would that make the anchor move around?
3. When I googled "screw in earth anchor" I found this site, which looks like it might be the site you were looking at: https://www.e-rigging.com/five-eighths- ... gI0oPD_BwE
They do have an instructions tab with charts to determine how many anchors you need for various size structures.

[LoTec]

As a footnote to the photo of my exhibit mill, here's what it's doing.

boothpump.jpg

[Missourimiller]

I was thinking if I took Angle iron and went from leg to leg at the bottom of the tower were it’s sitting on a horizontal angle rather then 4 individual points that would help put also. I’m in the Kansas City area so 4’ gets well below the frost line.

[LoTec]

If the weight is resting on an angle on top of the ground, and the tower is also anchored below the frost line, could there be a problem if the ground freezes and heaves up, while the anchor is not moving?

[Missourimiller]

I wouldnt think so. I haven’t had any issues with them being attached to my carport.

[Bryon]

Put your windmill up like it is the worst day of the year, not the best.

[Wayne]

I use the screw in anchors for my Mills. For short towers I dig 9 inch hole 24 inches put anchors in and fill with concrete. Taller towers deeper holes same principle. I use the anchors with the U bracket on top. Buy them at Lowes, Home Depot.

[Kansas Rust Buzzard]

I used to use those screw in ones for events where I displayed a Pipe Raymond on a 10ft tower, one time we had about a 65mph wind and it just about pulled the anchor out. After that I made a frame out of 1 1/2x 1 1/2 11 ga tubing and drilled 1 inch holes in the corners and beat 7/8 Rebar stakes down at angles and that took the wind a lot better. Remember, its not just the damage to the mill to worry about, its what the mill damages on the way down. Good Luck!