Just got to building the vertical stab on my somethin extra and when I put the 2 pieces together noticed that the 2 surfaces are not flat. They are angled so that the stab would actually looks bent at that joint. Is that how it is supposed to be?

no, the vertical fin should be straight

thats what I thought. Whats the best thing to do about it. This kit is supposed to be laser cut so the parts should fit exactly right.

yes they should, if I remember correctly there are round notches in the parts for perfect fitting, so sanding could be a bit dificult

what I would do is glue them togheter on a flat surface using epoxy and then fill the gap with balsa filler and sand

Yah I'm pretty sure I can fix it. Hmmph so much for "laser cut"

for sure you can fix it easy

6-

How exactly was the part not straight? Was there

1. a gap when you pressed the pieces together?
2. One of the pieces bowed up or down from the board when laid flat?
3. The laser cut line was not square to the sheet?

If your problem is either #1 or #2 it could just be due to different densities/grain patterns in the balsa sheets, or uneven swelling from humidity. Just lay the parts flat, weight then down and use a good gap filling glue in the joint. Be careful not to overflow the joint or you will leave a ridge that will never sand off properly. You can even leave the joint ever so slightly low and fill in later with light filler.

I would be very surprised at case #3, I never saw that in my SE. In fact I used to work for a company that makes laser cutters and that kind of problem is practically impossible unless you stick your hand in the machine and hold the board at an angle (something that cannot be done without disabling the safety cutoff switch on most equipment). But thats not to say impossible.

If the joint is really mismatched, you could have gotten a bad cut. Just call up Sig and I'm sure they would give you a replacement.

I glued the pieces together on a flat surface with CA. If you did it in the air, you could have gotten them bent. You can straighten them out on the bench and run some CA along the surface to hold the shape, but that will make sanding more difficult. You can use debonder to get them apart and re glue them, or you can sand them. The other option is to not worry about it and straighten them when you cover it. That is pretty easy too.

Sounds like you got a piece of wood that is harder on one side than the other. All of the tail pieces in my SE kit fit without a problem. But, if the wood is harder on the backside of the cut, it could very easily cause the laser to burn through more in one direction than the other.

John

A little windex does wonders on warped balsa. I use it on long parts that are bowed before building. Amonia and water will work.