Rotor Blade Straps

[automan1223]

I made a set of blade straps to reduce the rotor disc from 30' down to 28'. The skywheels blades are very heavy,


the new hub bar is a fixed pitch type like found in the rotordyne setups.


The aluminum hub bar is 1.250 thick milled down to 1" thk to accomodate coning angle, and has (3) 1/2 bolts securing the 2-2" wide x .250thk steel strap material. There are (4) - 3/8" bolts securing the blade to the straps in their original locations.

The steel material is your typical hot rolled spec but I feel that since I have pitch and track worked out


I will use grade 4130 bar ? to replace the hot rolled bar.


Is this material good enough for continued use ?


Is the old hot rolled stuff ?


how many lbs in tension is the straps with a 13.5' blade section turning 350rpm ?



Hence my earlier question about centrifugal forces acting on the blades. I know dragon wings have only 2 bolts securing straps to hub bar which is much lighter material, but the blades are also quite a bit lighter too.


Suggestions MR Beaty ?

Jonathan
Oriental NC