Just had minor scratches and chips repaired on my resin rotors by a man who knows how, at the same time he replaced the leading edge plastic protection strip. All looking nice and shiny so when I got them back home did checks on the weight per blade and cog distribution of each blade.



My rotor specs are



diametre total 8.3m (27.2')

rotor bar 1.3m (4.3')



weights

red blade 9871g

yellow 9870g

rotor bar 7100g

total 26841g



cog measured from blade root

red 1919 mm

yellow 1918 mm



To find and measure the cog of the blades I am sure there are commercially available products, but, I do enjoy finding my own solutions. For those with Fusion 360 I include a plan more precise.



I mounted the unit on a piece of aluminium 300x300x5 mm.



The top marker bar has a slot in it so that one can place a length of tape on the blade then mark the position exactly.

oops cannot upload the Fusion 360 file.

If you want a copy email me

phil (de fer)

Salut Phil (de fer),

so now what's the text step ?

as far as I understood I mean you had you refurnished with new gel coat, so I think you are going to ballance your 2 blades individually right ?

Hi Jean Mi.

Both blades are already statically balanced (as my previuos posting)
I do not imagine I can get them closer than 1g difference (9871g and 9870g) and the COG on each blade is within 1mm of each other.

Next is to remount the blades and the "H bridge Pulse Width Modulator" controller for the electric pre-rotator ready for a run up to check the tracking and then balance in flight.

Also want to fit my two anti-spill breather valves and pipes for the fuel tank.

phil