The larger the diameter of the pulley wheels the longer the steel cable will last. These pulleys are about 4″ in diameter. They have roller bearings and can rotate with a great deal of weight. This tower uses 3/16″ cable. The larger the cable diameter the larger the pulleys need to be for longevity.  The center pin of the pulley is bolted to the angle iron and the angle iron is sprayed with galvanizing paint. Refer to diagram to understand how the pulley system works to raise the tower.

I needed the bronze bearings to make sure there would not be much rotation that would cause the beam elements to wrap on the house facia and the neighbors trees along the fence line. I had about six inches or so clearance in the front and the back of the beam.

The 932 bronze bearings (bearing material available on Amazon) are bolted onto the square tubes. Four bearings are bolted to the top of the tube with flathead brass screws. The outside of the steel tubes are countersunk and a flathead brass screw is screwed into a taped hole in the bearing…4 screws used per plate.  The next section has bearings on the bottom with the countersink in the 932 bronze bearing and the tube tapped. Note that the inside tube has to be inserted first before the upper bearing can be installed. I used duct tape to hold the flat bearing between the tubes (yes there is clearance I made) so they can be screwed into the outside pipe. Refer to the diagram below to understand how the flat bearings attach to the tubes.

The mounting holes in the bearings and in the square mast tubing were made with the help of  a template drill  plate made of steel.

The bearing materials appear to have a low coefficient of friction on the galvanized tube.

I needed the bronze bearings to make sure there would not be much rotation that would cause the beam elements to wrap on the house facia and the neighbors trees along the fence line. I had about six inches or so clearance in the front and the back of the beam.

The 932 bronze bearings (bearing material available on Amazon) are bolted onto the square tubes. Four bearings are bolted to the top of the tube with flathead brass screws. The outside of the steel tubes are countersunk and a flathead brass screw is screwed into a taped hole in the bearing…4 screws used per plate.  The next section has bearings on the bottom with the countersink in the 932 bronze bearing and the tube tapped. Note that the inside tube has to be inserted first before the upper bearing can be installed. I used duct tape to hold the flat bearing between the tubes (yes there is clearance I made) so they can be screwed into the outside pipe. Refer to the diagram below to understand how the flat bearings attach to the tubes.

The mounting holes in the bearings and in the square mast tubing were made with the help of  a template drill  plate made of steel.

The bearing materials appear to have a low coefficient of friction on the galvanized tube.

The top bearing taped holes were first drilled with a small location pilot using a steel drill template which is also used to locate the holes in the bronze bearings
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