In my 2005 plans 'how to..' I describe how to furl to the right (looking at the wind turbine from upwind. that's how I always did it. the blades turn clockwise, again because that is the way I always have done it. In this situation, if the wind hits hard and the blades spin up very fast before furling, they do get pushed into the tower by the furling motion. It's amazing how far back they can bend without breaking (try it)! But when they do hit the tower they do break.
This is a very rare problem. If the blades are thick enough it should never happen. But for safety I have decided to change the habits of a lifetime and furl the left. Life is an adventure. It has been hard for me to get my head around the change but I like the extra factor of safety and so far as I know there is no downside to it.
All the designs in my new publication 'A wind turbine recipe book' furl to the left (although you could easily reverse this if you prefer for some reason). At present this book is only available in metric units but I am working on an inches edition and have set my self the goal of finishing it this year. Not long to go, yarg.
The new book is better in many ways (and no doubt worse in others) than the old one. Most notably it is better structured because I wrote it all in one go from scratch whereas the old one is a document that grew organically. So throughout the 2008 recipe book there are tables of sizes for each of six different machines from 4 foot up to 14 foot diameter.
It's a really organised piece of work. I am still polishing it a bit and I put the most significant changes on an upgrade page at http://www.scoraigwind.com/axialplans/recipe%20update/index.htm
That's another little job I will need to catch up with when the new editions come out. There will be 2 editions - metric and inches - for use with the two sizes of magnet and the two types of tape measure. I don't personally understand why anyone would work in fractions like 9/16" when they could use 14 mm but I realise that a lot of you do.
Sorry for rabbiting on but it's exciting to me.