In the interest of keeping it simple I did not explain that my zero incidence is technically incorrect! I was meaning that my flat bottomed blades are simply bolted to the hub with no packing at leading or trailing edges, so the flat undersurfaces are at same angle. This angle is 90 degrees to the mast, which however is slanted back. Because I use `delta` hinging I can use this method. Plenty of lift is generated, the other day a gust blew up as I was preparing to hadlaunch and the upwards pull was so strong I could hardy hold the plane. A bit scarey! I admit my hubs are simple, you could say crude! But they do the job for planes up to .40 glow power.