I received my ch750 kit in March and have completed the rudder. I am trying to learn how to use this forum and since I have run across a problem I figure this is the time to learn. I have completed the skeleton of the horizontal stabilizer and am fitting the skin. It seems that the 4 ribs are too long and have pushed the rear spar back about 3/32 of an inch or about the width of 1 and 1/2 holes. It I sight along the rear spar I can see that it is bowed and the holes in the spar do not line up with the holes in the skin. The tip ribs seem to be fine as I can line up the holes at the tips. If I remove the 4 ribs and allow the rear spar the be straight then the holes line up fine with the spar and skin but the ribs will not fit because they are so tight. I would appreciate anyones help on this matter. Thanks.

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David - With just the skeleton clecoed together; ready for the skin; measure distance between holes starting from the nose rib going back to the rear spar. Compare those distances to that of the same holes on the skin. Checking them seperately there's a chance you can identify the problem.

Thanks, I will do that. I can't help but think that I have something on wrong so I had another builder stop by and he is puzzled also. I will check your sugestion after work today. Thanks

Sorry to dig up an old post but did you figure out what the issue was? I'm having the exact same problem.

I had a similar problem with the wing and I had to slightly alter the radius of the 90 deg bend of the rib where it attaches to the spar to make it somewhat longer or shorter. Especially on the wing, all the ribs are the same length but there is one  rib that has a doubler behind it at the spar and that rib should have had a separate part # and actually should have been about 1/8 inch shorter. I took that rib and made a wood block with a radius and clamped the two in a vise and gently tapped the front edge of the rib and moved the radius back a little bit. I am in no way an authority or have any kind of engineering background so I hesitate to give advice but that is how I got around the problem. I am satisfied with the result. The holes lined up fine then.

That is what I have been contemplating on doing. Just wasn't sure if it could be avoided. Since I didn't notice a problem until it was time to put the skin on, the holes that I opened up to a #30 on the front and rear of the rib will no longer be in exact alignment. I am debating if I should just order new ribs and modify those.

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