step by step guide to building your own 3.2 or 3.5 meter high voltage MPPT wind turbine

 

Basic Turbine Head Frame

 

The yaw tube of the turbine is built from a 12" long piece of 3.5" Schedule 40 pipe. This slips over 3" Schedule 40 nicely, so the 3" is used for the yaw shaft/tower stub. Notice in the below photos that I use a bottom thrust flange. The reason I do this is because the generator cable must pass thru the yaw assembly. If you simply cap the top of the yaw tube and set it over the shaft you must use some sort of washer or thrust bearing between the top of the yaw shaft and tube. This introduces the possibility of chafing the generator cable. So I prefer the bottom thrust flange.

Note on schedule pipe dimensions - in the US we use NPS (Nominal Pipe Size) for this. The European stadards are DN (diamètre nominal/nominal diameter/Durchmesser nach Norm), in which sizes are measured in mm. You will have to make the conversion to the European DIN standard if you are a European builder.

Shown in the photo to the left, a ring is cut from 1/4" (6mm) steel and welded to the yaw shaft. Another ring is cut and welded to the bottom of the yaw tube. The ring on the yaw tube should be slightly larger OD than the ring on the shaft, since this helps prevent rain water from getting into your thrust flange assembly.

There is a grease fitting (not shown) that is screwed into the yaw tube to lubricate the yaw assembly.

This yaw assembly provides a very robust system that will support a heavy turbine with ease, and it yaws and faces the wind with the slightest breeze. It also does not stick or seize, or prevent proper furling action of your turbine.

The rest of the head frame consists of a piece of 12" long x 10ga (3mm) wall tubing for the torque tube. And a 18" (457mm) diameter stator support plate cut from 3/16" (5mm) steel. There is not much explanation possible for this. It should be mostly self explanatory. The only real details are that the torque tube is positioned so that it has about 6 degree upward tilt for the mainshaft. This helps provide extra blade clearance on lattice-type towers. The prop (turbine rotor) is positioned a fair distance forward of the yaw and the generator that goes on the rear is positioned fairly close to the yaw.

The tail hinge must be welded on so it is at 45° to to the mainshaft and the angle of the tail hinge pin is 18° from vertical. This dimension is very critical for proper furling action. The offset of the mainshaft centerline to the centerline of the yaw is exactly 5" (127mm). This dimension is also critical for proper furling.

The following is several photos of the basic head frame

© 2012 Chris Olson, Dairyland Windpower - all rights reserved Next - mainshaft and bearings ->