Short question. I just started construction on an old Great Plains Super Kaos. I built one of these about 15 years ago and had no problems. When I laid the wing out on the table, the pre notched spars, trailing edge and leading edge are about a 1/4" longer than the depiction on the plans. Does the old plan paper shrink over time?

john

Do the notches line up with the plan?

Each one is just a bit off until at the outboard rib, the error is about 1/4". I can build it with the notches as a guide. I am sure the cut wood is accurate as all of the spars, trailing edges and leading edges all line up. I was just curious if anyone had seen plan shrinkage with old kits. This one must be about 15 to 18 years old. I personally would not have built it, rather collect it, but my kid bought the kit and asked me to build it for him for Christmas. Why not, the one I originally built is just about restored, so we can have two "old" maiden flights the same day.

John

John,

That is interesting. I have a set of RCM plans (very yellowed) for my Cold Duck that were printed in 1971 and the wing span on the plan measures perfectly to my original hand drawn plans.

Oh well, the wings are all framed up now. They look exactly like the KAOS I am restoring. (Mp covering on the wing at the moment). I shall have to let you know how it goes. Just have to get it done by mid Jan when my son gets here

John

I've read that plans can shrink or enlarge 3 to 4 percent from humidity. That's why a lot of machine prints have a scale on them. You measure the scale to see what it reads and enlarge decrease as needed. Second thought would be if the plans were copies that might have something to do with it also.

Dennis

I have a copy of kit drawings of a Bridi Dirty Birdy 40. The previous owner had traced the ribs on the plan. The spar position on the ribs do not match the location on the plan view of the wing.

Waiting for a Bridiairplanes (Bluejay) Utter Chaos 40 kit. Watch for build thread. Haven't built a kit in years. This is going to be fun again.

Paper is wood. It will shrink and expand with changes in humidity and temperature. Wood after being sawn from a log will shrink approximately 7% in width and thickness once dried. The length will change a very small amount. The sawing type (flat, quarter or rift) will also effect the material.
EXCAP232

jlingrel, If possible, would you please post some pics of your Super Kaos under construction? I'm pretty certain that this is the plane I want to build necx (RCM plans) and I'd enjoy seeing details of its construction. Thanks.

I can do that this weekend. I am just about ready to join the wing halves. But I can do more of a build thread on the fuse.

John