I have finished my adjustable pitch prototype VAWT.
Ill post some pictures soon. For now, some of my notes.
I started with the base bearing. I found a wheel bearing and race worked REALLY, REALLY well.
I mounted the race in a 6"x6" sheet of 3/4 inch plywood. The race is 4 inches in diameter 3/4 inches tall. I cut a 4" hole in the plywood and wedged in the race. I used a few pieces of .35" ply to hold the race from sliding through on the back side.
The bearing has a 2in hole for the axle. I found some schedule 80 2" PVC fit so perfectly, so i used it. The shaft is 2' tall. I am using a 2" race and wheel bearing at the top of the shaft affixed with a hose clamp.
The blades are affixed on another 6"x6" sheet of 3/4" plywood. In the center of the wood is a 2" hole to slide over the axle. 15" arms extend at 360, 90, 180, and 270 degrees. These arms are .5" x 2" furring strips.
1 inch from the end in the center of the arms, I drilled a .25" hole for the pivot shaft for adjusting the pitch of the blades.
6" pieces of the same furring strips are affixed to the ends of 6" x 24" x 2" pieces of foamboard for blades.
These blade holders also have a .25" hole in the centers for the pivot shaft for pitch.
I am happy with the performance of this proto.
I cut everything to a 16th inch tolerance, and have loaded the bearings with a different lubricant. Standard wheel bearing grease was too stiff for the weight of the device. A lighter weight teflon lube was used to with great results. It spins to about 250 RPM very quietly and the balance is very good considering the quickness I built it. (About 30 min.) The top bearing being held on with the hose clamp puts a little weight on one side. Elimination of this as well as stiffer components cut to higher tolerances should lead to a very effective device.
The blades will most likely stay this material with a few pieces of all-thread run lengthwise and a wrapping of fiberglass and resin for stiffness and protection.
Tests will continue with this device until I find a happy pitch to set the master to.
Ill post some pictures soon. For now, some of my notes.
I started with the base bearing. I found a wheel bearing and race worked REALLY, REALLY well.
I mounted the race in a 6"x6" sheet of 3/4 inch plywood. The race is 4 inches in diameter 3/4 inches tall. I cut a 4" hole in the plywood and wedged in the race. I used a few pieces of .35" ply to hold the race from sliding through on the back side.
The bearing has a 2in hole for the axle. I found some schedule 80 2" PVC fit so perfectly, so i used it. The shaft is 2' tall. I am using a 2" race and wheel bearing at the top of the shaft affixed with a hose clamp.
The blades are affixed on another 6"x6" sheet of 3/4" plywood. In the center of the wood is a 2" hole to slide over the axle. 15" arms extend at 360, 90, 180, and 270 degrees. These arms are .5" x 2" furring strips.
1 inch from the end in the center of the arms, I drilled a .25" hole for the pivot shaft for adjusting the pitch of the blades.
6" pieces of the same furring strips are affixed to the ends of 6" x 24" x 2" pieces of foamboard for blades.
These blade holders also have a .25" hole in the centers for the pivot shaft for pitch.
I am happy with the performance of this proto.
I cut everything to a 16th inch tolerance, and have loaded the bearings with a different lubricant. Standard wheel bearing grease was too stiff for the weight of the device. A lighter weight teflon lube was used to with great results. It spins to about 250 RPM very quietly and the balance is very good considering the quickness I built it. (About 30 min.) The top bearing being held on with the hose clamp puts a little weight on one side. Elimination of this as well as stiffer components cut to higher tolerances should lead to a very effective device.
The blades will most likely stay this material with a few pieces of all-thread run lengthwise and a wrapping of fiberglass and resin for stiffness and protection.
Tests will continue with this device until I find a happy pitch to set the master to.
