I tried the string method including monofilament. What I found Was even
under high tension the string sags from gravity. I measured all the hinge
brackets and found they were all exact, so I did the following.
Instead of using a string I spent a lot of money and bought a 9ft. straight
edge from McMaster Carr, it is calibrated to within .004/inch. I took the
straight edge and vertically put it across the top flat edge of each hinge,
that gave me horizontal alignment of each hinge. then I put the straight
edge horizontal along the face of each hinge. Since all the hinges are the
same dimensions it was easier to use the hinge frames as a reference instead
of trying to guess where the center of a bearing hole was with a string
using my eyes.
The straight edge will come in handy for other things like landing gear and
wing trailing edges, just dont drop it and spring the temper out of
alighnment.


Dale Wills