Making the Weldment and Bearings


I have come to the task of preparing the weldment assembly. I purchased the basic setup from Randy Burmeister from Randy's Workshop. This was 1/8" steel plate forming the body. I got a chop box for cutting steel and a 230A arc welder from Craig's List. I got the first from a friend for free; I got the welder with the helmet, sticks and extension for $99. After drilling some holes I fabricated a steel arm to hold a motor bike disc brake. The brake is 6.375" in diameter and 150 pounds of pull on the cord will create 4800 pounds of pressure on the disc. I need something that I can use to stop the turbine if it gets out of control.

The base will attach to a 1.875" diameter pipe using a Yaesu GS-050 thrust bearing. I am waiting to get a Mercotac rotating mercury connector to insert into the bearing so the weldment is free to rotate without tangling the output wires.

The shaft is held in place on the front by a screw; the bearing is held by the stator. The rotor will go here so the screw is not coming off. In the rear the bearing is held in place with steel plate. I want to point out that I initially used sealed steel bearings. They were good, but I replaced them with high speed hybrid ceramic stainless steel bearings. They do seem to make a difference with the start-up wind speed and top speed. I got my bearings from


The shaft is secured using PVC pipe. This keeps the shaft from moving laterally. The disc's center hole is cut to match the spline on the shaft. It is free to move a few millimeters laterally so it does not grap the pads during normal rotation, but is able to get pushed against the static pad when the brake is engaged.

On the last picture at the lower right you can see a piece of steel jutting out from the tail pivot. This is a stop bar so the tail does not get too close to the rotor. The tail pivot (which I will show later) allows the tail boom to clear the disc; however, I am not sure how much the tail boom could bend in strong winds and I did not want it getting within a few feet of the blades.

Here are some pictures: