Here's the Red Baron up on it's permanent tower and ""flying""
If the letters in our mailbag are any indication, many of MOTHER's readers crave information about homebuilt windplants. In fact, the response to our three-page feature on Marshall Price's basement-built unit (see issue 84, page 130) was so encouraging that we decided to go ahead and launch a test program of our own to determine just how simply and inexpensively a reliable and productive wind generator could be put together by the average person.
The plumbing-and-fabric appearance of our windplant earned it the nickname of the Red Baron among our staffers . . . but that antiqueaircraft look belies the fact that the 70-watt plant is fully capable of providing a 25- or 50-watt light source plus a 2-amp battery trickle charge to what was an unpowered outbuilding.
Now, wind power seems intimidating to many people, and—in truth—it is a formidable subject. In fact, we can't even begin to describe the whys and wherefores of our engineering on this plant, because it'd take several articles. If you're really interested in wind theory and application, we'd suggest The Wind Power Book, by Jack Park, an excellent information source which is available from Mother's Bookshelf for $14.95 (see insert following page 80 for ordering information). But in the meantime, if you favor the empirical approach and hanker after something you can afford to get your teeth into, this little job won't disappoint you.
We had set our sights on keeping costs below $50 when planning our prototype . . . but after purchasing nearly every component new, the bill just topped twice that figure. Still, a quick glance at our materials list should convince even a die-hard pessimist that costs could be reduced by scrounging the common parts . . . and we'd be willing to venture that it wouldn't take a whole lot of effort to assemble the entire plant—minus the storage system and the tower—for $60 to $75.
In a nutshell, we believe that we've come up with a working wind machine that not only will provide its builder with hands-on experience and usable electrical energy, but will serve as an excellent monitor of wind conditions at a specific site, and could thus be an excellent "trainer" for folks who are contemplating the purchase of a more costly plant. All that, for less than most people would pay for a simple anemometer!
• Using a hacksaw, remove the top half of the 1" T to create a cradle. Bevel the cut edges and smooth the corners with a file or grinder.
• Fasten the T to the 1" X 3" nipple, and the nipple to the remaining 1" T. Use the pipe nuts to lock the fittings together.
• Assemble the close nipple, the elbow, and the 12" head mast pipe, using the remaining two pipe nuts as locks. Drill a 3/8" hole through the outside corner of the elbow.
• Drill a 7/16" hole lengthwise through the head end of the pipe plug and tap it for 1/2-13 thread. Screw the plug into the open end of the mast mount T. (You can purchase a tap-and-die set, for cutting thread, fairly inexpensively at any hardware store . . . or perhaps a friend will lend you one.)
• Place the idler pulley on the 1/2" machine bolt with a washer on each side of it. Thread the bolt into the pipe plug to the limit of the threads. (If necessary, use a 1/2" nut to lock the bolt shank to the plug.)
• Drill two 13/64" holes through the collar of the 1/2" X 1-3/4" pulley so they're equidistant from each other and from the set screw that's already in the collar. Tap the holes for 1/4-20 thread and install the two additional set screws.
• Cut the generator shaft down to 1-1/2" in length. Place the pulley on the shaft and lock it in place, tightening each set screw an equal amount so the pulley is centered on the 15/32" shaft and doesn't wobble.
• Clamp the generator into its cradle, making sure the drive and idler pulleys line up, and the 1/4" X 3/4" X 4" wooden block is secured under the straps.
• Cut an approximately 2" X 7" opening into the side of the plastic pop bottle and slip that housing in place over the generator. Drill two 1/16" holes through the bottle and the block below it and install the two housing screws.
• Cut the 17mm motorcycle axle to a length of 3-3/4". Drill a 5/16" hole 1" deep into the cut end and tap it for 3/8-16 thread. Use a 3/8" NPT die to cut threads into the outer end of the shaft, as well.
• Cut two 1" pipe couplings to 3/4" lengths, and the third to a 1" length, to make the outer race spacers.
• Cut a section of 3/4" electrical metallic tubing into two pieces, one 3/4" long and the other 1-5/8" long, to make the inner race spacers.
• Drill a 13/16" hole through the large collar of the 1-1/2" X 1" pipe reducer coupling. Tap it for 1/4-20 thread and install one 1/4" X 3/8" set screw. Repeat this procedure on the 1/12" pipe cap, then drill a 1" hole through its face.
• Drill a 3/8" hole in the side of the 1" pipe cross, then thread the 1" close nipple into the cross, and the 1-1/2" X 1" reducer coupling onto the nipple.
• Slip one bearing onto the motorcycle axle, then place the 3/4" X 3/4" tubing spacer and the 3/4" X 1" pipe coupling spacer over the shaft, followed by the second bearing. Next, slide on the second 3/4" X 1" pipe coupling spacer, the 3/4" X 1-5/8" tubing spacer, and the 1-1/2" pipe cap.
• Grip the head of the motorcycle axle in a vise, with the shaft pointing upward. Screw the 1-1/4" X 3/8" pipe reducer bushing onto the threaded shaft, head first, then lock it in place by tightening the 3/8" X 1" bolt and one or two washers into the hole tapped in the center of the shaft.
• Place the 3/8" fender washer and the 1" X 1" pipe coupler into the 1-1/2" X 1" reducer coupling and tighten the 1-1/2" X 2" pipe nipple into the coupling. Slip the rotor shaft assembly into the housing, making sure the spacers are centered and lined up with the bearing races. (They must not press against the seal rings!)
• Slowly tighten the 1-1/2" pipe cap onto the 1-1/2" X 2" pipe nipple housing until there's no noticeable end play in the rotor shaft. Check the shaft for free movement, then lock the cap and reducer coupler set screws tightly against the pipe nipple housing.
• Drill a full 13/64" hole through the side of the 1-1/4" X 8" pipe and tap it for 1/4-28 thread. Screw in a 1/4-28 grease fitting, then thread the 1-1/4" X 2" pipe reducer coupling onto the pipe.
• Thread the 1" X 10" pipe into the 1" pipe cross so it forms a perpendicular with the rotor shaft. Make sure the 3/8" cable hole is at the right side when the frame is viewed from the front.
• Slip the 1-1/4" pipe lolly housing assembly over the 1" X 10" pipe, then drill a 1" hole through the face of the 1" pipe cap and thread the cap onto the end of the 1" pipe, tightening it with locking pliers.
• Thread the 2" X 3" pipe nipple into the reducer coupling and use a grease gun to lubricate the swivel surfaces.
• Cut a length of 1/2" electrical metallic tubing into two 46" pieces. Using the diagram on page 102 as a guide, form the tubing with a conduit bender to the configuration shown. (If you don't own such a tool, an electrical contractor should be able to do the job for you.)
• Lay your sheet of canvas or polyethylene on a flat surface and cut it to the dimensions shown in our diagram. Place each section of frame tubing at its respective fabric border and temporarily fold the fabric's edges over the metal to create sleeves, then mark their positions. Measure to determine the location of the two rib members, and mark their positions, as well.
• Remove the tubing and stitch up the sleeves, using a double seam. Cut two 1" X 38" strips from your leftover fabric scrap and make sleeves for the rib members by stitching the strips directly to the fabric at the marked locations.
• Slide the frame sleeves over the tubing by working with a small section at a time. Then slip the 3/8" X 34" dowel rods into the rib sockets, and stitch up the tail's rear hem. The curved front hem can then be seamed, and some strengthening stitches can be added at stress points, such as those where the tubing and ribbing terminate.
• Thread the 1" X 3/4" pipe reducer bushing into the pipe cross, opposite the rotor shaft, then thread the 3/4" X 10" pipe into the bushing. Cap that pipe with the 3/4" T and tighten it so it's in the same plane as the lolly housing pipe.
• Bore the centers of the three 3/4" X 3/8" pipe reducer bushings to 3/4" diameters, then saw through each one's wall longitudinally to create split nuts.
• Cut the base from the 3/4" pipe floor flange, leaving a 90° segment of flange attached (as shown). Drill two 1/4" holes through the flange about 1" apart, then bore a 13/64" hole into the fitting's collar.
• Cut a piece of 3/16" X 1-1/4" flat stock to 14" in length, center it over the holes in the segmented flange, and drill two 1/4" openings to match those on the flange. Bore one more at each end of this piece, then fasten the arm to the flange with two machine bolts.
• Slip one split nut over each exposed section of tail frame tubing, head first. Then slide the control collar assembly over the upper frame tubing (collar first) followed by the third split nut, head first.
• Carefully guide one, then the other, tubing end into the 3/4" pipe T, and tighten the split nuts into the T and the flange. After checking to be certain the tubes are well seated, position the control collar arm so it's perpendicular to the tail, and drill a 13/64" hole into the upper tail frame tubing, using the hole in the control collar as a guide. Install the 1/4" X 3/4" self-tapping screw to lock the collar to the frame.
• Loop the 1/16" X 20" cable through the hole at the right end of the control collar arm and clip it in place. Slide the 5/16" X 12" tension spring over the cable and loop its end through the hole.
• Position the tail in the same plane as the rotor shaft, then form a loop at the opposite end of the cable so it terminates at the collar of the 1-1/2" pipe cap on the front of the bearing housing. Drill a 13/64" hole into the collar and fasten the spring and cable to the cap with the 1/4" X 1/2" self-tapping screw.
• Pass one end of the 1/8" X 30' tail control cable up through the lolly axis pipe and out the 3/8" hole in the side of the 1" pipe cross. Loop it through the remaining end hole in the tail control collar arm and clamp it securely. At this point, you can also thread some 14-gauge, 2-conductor household wire through the lolly axis pipe and the head mast, draw it through the hole in the head mount elbow, and secure the head mast to the 1" pipe cross.
• Cut two 22-3/4" disks from a section of 5/8" plywood and remove a 16-3/4" circle from the center of one to form a ring. Cut twelve 3/4" X 2" X 3" wooden blocks.
• Clamp the plywood ring and the disk together. Then, using a 1-3/4" hole saw, bore four groups of evenly spaced holes through both pieces—twelve in all—leaving room between the groups to mount the 2 X 4 blade platforms. Be sure to center the holes between the inner and outer edges of the ring.
• (Place the 3/4" X 2" X 3" wooden blocks between the ring and the disk so their longer edges butt against the plywood surfaces and they're spaced evenly between the aligned 1-3/4" holes. Use a No. 8 Stanley Screwmate drill and countersink tool to bore mounting holes through the plywood and into the blocks between, two to each spacer's side. Tighten the No. 8 X 1-1/4" flathead screws into the holes.
• Cut a section of 2 X 4 to a 22-3/4" length, then lay it on the face of the plywood disk so it's perfectly aligned at the ends and bisects the exact center of the disk. Position the holes for the 1/4" X 2-1/2" carriage bolt fasteners by gauging them with a section of 3/4" conduit and the tubing clips. Use wood glue on the joining surfaces, and mount the board.
• Cut two more 2 X 4's to 9-1/2" lengths, and center them perpendicular to the first. These will require 1" X 3-1/2" X 11" cap platforms, so place them over the 2 X 4's before you bore the mounting holes, then apply the glue and install the ten 1/4" X 3-1/2" fasteners.
• Make the nose supports by cutting four 1-1/2" X 3-1/2" X 6" wooden blocks and sawing joining 45° bevels into one end of each. Bore a 1-3/4" hole through the center of each block and mount the blocks against the blade platform joints, using No. 8 X 1-1/4" flathead screws fastened through the plywood disk.
• Determine the exact center of the newly made hub and attach the 1-1/4" pipe floor flange at that point to the rear face of the plywood disk, using the four 1/4" X 2" lag screws. (The holes in the flange will probably have to be enlarged slightly.)
• Once the hub mount is secured, you can clamp the main frame in a vise and attach the hub to the rotor. With this done, tap the spokeless bicycle rim over the edge of the plywood pulley hub and align it. Spin the hub to assure the rim's trueness, then fasten the rim to the ring with No. 6 X 3/4" ovalhead wood screws placed through the spoke holes. Remove the hub and file the screwheads lightly so they won't damage the drive belt.
• Make the blade frames by bending two sections of 3/4" electrical metallic tubing to the specifications indicated in our diagram on page 102. Place the frames on their platforms, one atop the other, so that when you're looking from the front of the hub, the curved ends are leading as the hub turns in a clockwise direction.
• Center the blade frames and check to see that each one's pitch is equal, then—when you're assured that the hub glue is dry-remove the appropriate platform fastener nuts, install the twelve 3/4" conduit clips to capture the electrical metallic tubing, and retighten the fasteners against the clips. To prevent the blade frames from rotating on their longitudinal axis, lock them by screwing a No. 8 X 1/2" sheet metal screw into each tube through one of the clips. Then pass an 18-1/2' length of 3/32" cable through each blade frame so it protrudes from both ends, pierce the plastic leg tips, and slide them onto the tubing ends.
• Lay the four sheets of polyethylene or canvas on a flat surface and trim out the fabric blade sleeves, using our diagram as a guide. First fold and stitch the straight ends as shown, then fold each section lengthwise and double-stitch the joining edges. Turn each blade sleeve inside out to hide the seams.
• Bore a 1/4" hole crosswise through each forward blade platform (about 1-1/2" from the end), counterbore the rear edge 1" deep with a 3/4" bit, and install the 1/4" X 3-1/2" eyebolts. Make loops on each end of the blade tensioning cables, install the cable clamps, and fasten the turnbuckles to the cable loops by closing the eyes around them. Two turnbuckles then get attached to the 1/4" X 3-1/2" eyebolts, and the remaining two are fastened to the outermost carriage bolt stems on the rear blade platform with nuts and washers.
• Tension the turnbuckles so the leading edge of each blade frame just begins to arc slightly (don't overdo it!) and slip the fabric sleeves over the frames. Press two grommets into the end of each sleeve, positioning the holes about 5" apart.
• Use the shorter nylon ropes to connect the grommets directly opposite each other, then weave the longer ropes through the turnbuckle eyes to join the complementary blade sleeves. Tie the cords snugly, but don't overtighten them.
• Cut a 5/8" X 9" disk from a scrap of plywood and bore a 3/8" hole through its center. Countersink the center slightly and attach the 3/8" X 5-1/2" threaded rod to the disk with two nuts and washers.
• Align the disk over the 6"-block nose supports and fasten it in place with the No. 10 X 2" flathead wood screws. Drill a 3/8" opening in the bottom of the salad bowl, thread double nuts onto the 3/8" rod, and lock the bowl in place with the final nut and a washer.
• When beginning the final assembly of the windplant, be sure to place the drive belt over the rotor shaft before installing the hub and blade assembly. and don't overtighten the belt. (Tension is adjusted by rotating the generator mast mount T as necessary.) Also, remember to fasten the generator wires to the conductor wires before mounting your windplant . . . and if you've chosen a canvas covering rather than a polyethylene one, you'll want to seal the fabric—as well as the metal parts—with a coat or two of paint.
The beauty of our Red Baron "trainer" windplant lies in its simple design and low cost . . . and that means it can serve the dual role of entrylevel generator and site monitor, and do so quite economically.
Of course, careful site selection is important, and the machine won't be functional where average annual wind velocities are less than 10 or 12 miles per hour. (Faced with an average windspeed of 7.31 mph, we did a lot of testing using a tower towed behind a truck.) But feel free to experiment with blade length and pitch to suit your circumstances . . . you may be surprised!
Remember that conditions can vary considerably even between neighboring sites, so choose your location carefully and be prepared to accept seasonal calms. Remember, too, that unless your site faces a sizable body of water, the plant should be mounted 20 or more feet above any obstructions . . . and at least several hundred feet away from them.