By trying to span the bow, applying force with a long lever, two things happen:
1.- The string goes far above the nut making impossible to cock it. Geezer suggested me to go further back passing the nut and than slowly go back and the string goes down by itself. This I did it and finally the string was in place
2.-The force I need to pull the string back is too much, (nothing to do with Tods videos where he pulls the Gafa lever with two fingers).
My bow is 900mm. long, 40mm. wide in the middle, and 11mm. wide at the tips, the bow is made of automotive spring steel, with a thickness of 6.4 mm.6.4mm.
I would appreciate if you make me your recommendations for I am sure that I have done somethin wrong, possibly in the geometry of my gafa, or the bow with these meassures has got a draw weight far above to be cocked with it and I need a cranekin.