Measuring Wing Icidence Positions

Hi All,

I'm finally plugging my wings in today and will be drilling the rear spar, but had some questions first about where to take the wing incidence measurements. In the diagram on drawing 38, it mentions that the forward end of your level should be even with the forward surface of the main spar web, however it doesn't specify a position for the rear. Just to confuse the matter, on the RV-8 assembly DVD RV Builder Basics, it shows them measuring the forward end between the two skins, and the aft end at the rivet line.
Does anyone know where specifically this aft measurement should be taken for the RV-7?
Tom.

I lined up the forward surface of the block to the aft spar of the wing.

Hi Mel. I just measured this on my -7 and the forward/aft skin butt joint line is 1" aft of the forward face of the spar web. Perhaps it is different on the -6. What I am really keen on finding out is at what point do you measure on the rear spar. Is it at the forward face of the rear spar web, at the rivet line, or somewhere else?
Tom.

front and rear spar webs

I just got the following response from Van's tech support team which clears things up.
"The locations you are making this measurement from is not a rivet line or the joint where the skins come together. You want to have the level even with the vertical portion of the spar web and same with the rear spar for your block.
Sterling "

My Bad!

tgmillso said:

Hi Mel. I just measured this on my -7 and the forward/aft skin butt joint line is 1" aft of the forward face of the spar web. Perhaps it is different on the -6. What I am really keen on finding out is at what point do you measure on the rear spar. Is it at the forward face of the rear spar web, at the rivet line, or somewhere else?
Tom.

Click to expand...

Just looked at the "7" plans. You're right. Sorry about that.

tgmillso said:

Hi Mel. I just measured this on my -7 and the forward/aft skin butt joint line is 1" aft of the forward face of the spar web. Perhaps it is different on the -6. What I am really keen on finding out is at what point do you measure on the rear spar. Is it at the forward face of the rear spar web, at the rivet line, or somewhere else?
Tom.

Click to expand...

The -6 is different.

They use the skin butt joint at the forward end, and a 3.03" spacer over the rear spar web at the aft end.