Stealth VAWT Upgrades.
Over the last couple years, many people who had watched my ‘Building the Stealth VAWT’ video asked me a question, “How much”? Well, that answer depends on whether you need parts or the whole thing. Unfortunately I haven’t had an accurate answer until now. The first Stealth VAWT was made strictly as a proof of concept experiment. The next two were made as an exact matched pair in order to compare the performance of a WindBlue low wind PMA to a 48 volt Freedom PMA. I used less expensive rivets and bolts than I would have if I was building the things for someone else. Stainless steel fasteners are always preferred over aluminum rivets or plated nuts and bolts. There are also weak spots where I expected eventual failure. I had a good idea of what I needed to do to strengthen those places but chose not to worry about them for various reasons.
Of course now that someone has taken the plunge and ordered, I’ve purchased those higher quality fasteners and made those necessary vawt upgrades on my first customer purchased Stealth VAWT. After all, I want anyone who buys my product to have worry free use for many years to come. To borrow a term from Ron Popeil, “just set it and forget it”.
Reinforced the Weak Spots
Better fasteners are only one aspect of the Stealth VAWT upgrades. In my original design, only a small tab of aluminum is holding the blade to the blade mounting ring. Even though I have never seen a blade break free from any of my three prototype VAWTs, this is a known weak spot and needed to be addressed before building a turbine to be purchased. So what is the upgrade? Now each blade has an eight inch long, 1/8″ inch thick x 3/4″ inch wide aluminum reinforcement bracing those tabs. They are drilled on one end to accommodate the two 10 x 32 stainless steel bolts that hold the blade to the mounting ring. The opposite end has a 1/4″ inch hole for the stainless steel wire keeper that holds the tension wire. The stainless steel wire keeps the blades equally spaced and balanced without causing wind resistance. These new structural pieces are a bit like adding a skeleton to a flower. It may not be necessary, but after a strong storm I’d expect to see the petals still in place.
Carefully Placed Bends Add Strength
The third improvement not only adds strength to the blade, but (in my eye) makes it just a bit more aesthetically pleasing. I have added one more bend to the vertical blades. This ¼ inch wide outward bend on the outer edge of the vertical blades should help keep those long edges straight through most of the thunderstorms nature might throw at it.
Last but definitely not least is the taller blades. The original stealth vawt has a 32″ inch diameter and is 36″ inches tall. The new version blades are the same diameter but are 48″ inches tall. Just imagine if you were to lay out the blades end to end from this new turbine. You would have a total blade surface 6″ inches wide by 48″ feet. Now try to imagine how much torque those blades can create in a very light breeze. cogging is not a problem for this turbine.
Prices change with the cost in materials. Please check out the parts and prices page for updates on complete units. Or if you are adventurous and plan to build your own VAWT, you may purchase individual parts on the shop page.