Group,
I have just completed my wing stand with everything square and level. Second, I mounted the riveted wing skeleton in the jig; checked and removed sag (fishing line method & screw jack); wing spar is leveled to 0-degrees (Smart Tool) both directions. I then installed the top inboard and outboard skins (clecoes). I did not fix the position of the rear spar to the wing jig. I hung plumb bobs on both inboard and outboard edges of the wing and measured from the skin at the rear spar line to the string (It would appear to me that this measurement should be taken with the skins fixed in place; instead of from the edge of an unskinned rib). From measurements taken it appears there is some twist in the wing. Measurements: Right wing inboard 2 24/32"; Right outboard 2 21/32"; Left inboard 2 16/32"; Left outboard 2 20/32". I saw where Dan C. was measuring this distance down to 1/128.
The question I have is what is a reasonable tolerance? Also, if I set and fix the position of the rear spar to remove any of the apparent twist, It would only appear that I would be placing the wing in tension (the match hole design and clecoed skin would appear fix the position of the wing). I have not match drilled any of the skins at this point. I think that even if I fix the rear spar to remove any apparent twist and match drill the skin to the skeleton, once I unclamp the rear spar, the wing may likely return to the current position.
Any advice as to how to better address this alignment issue?
I have just completed my wing stand with everything square and level. Second, I mounted the riveted wing skeleton in the jig; checked and removed sag (fishing line method & screw jack); wing spar is leveled to 0-degrees (Smart Tool) both directions. I then installed the top inboard and outboard skins (clecoes). I did not fix the position of the rear spar to the wing jig. I hung plumb bobs on both inboard and outboard edges of the wing and measured from the skin at the rear spar line to the string (It would appear to me that this measurement should be taken with the skins fixed in place; instead of from the edge of an unskinned rib). From measurements taken it appears there is some twist in the wing. Measurements: Right wing inboard 2 24/32"; Right outboard 2 21/32"; Left inboard 2 16/32"; Left outboard 2 20/32". I saw where Dan C. was measuring this distance down to 1/128.
The question I have is what is a reasonable tolerance? Also, if I set and fix the position of the rear spar to remove any of the apparent twist, It would only appear that I would be placing the wing in tension (the match hole design and clecoed skin would appear fix the position of the wing). I have not match drilled any of the skins at this point. I think that even if I fix the rear spar to remove any apparent twist and match drill the skin to the skeleton, once I unclamp the rear spar, the wing may likely return to the current position.
Any advice as to how to better address this alignment issue?