i am pretty much finished building my sig se and it was my first time building anything but i build furniture for a living so i figured i could do it. anyway i am nearly finished and ready for covering and i have the plane put together and i measured from the wing tip trailing edge to the back corner of my elevator and i got a number and i measured the same thing on the other side and its about 5/16's off. after that i checked from the tip of the fuse to leading edges of the wings and thats off a bit too. im pretty shook about this cuz i dont have a clue how it happened but whats done is done. im wondering if its even gonna fly?

As long as the wings and tail feathers are straight, that is, no twisting warps, the difference you mention shouldn't be enough to affect the flying.

Any effects as a result of the error will probably be trimmed out when you first fly it.

Incidentally, on your first flight be sure to set the aileron travel as low as 40% rate or lower, or you run the risk of screwing it into the ground faster than you can blink!

Good luck and have fun. It's a great plane!

-David C.

The plane should fly fine. These planes are fairly tolerant of slight misalignments. Did you know that on the full scale Beaver, each wing tip can be off by as much as 1" while rigging the wings?

I just hope it will fly. I have spent so much time on this plane trying to make it perfect and I pretty much felt like a failure when i noticed how the wings arent measuring the same.

Foxtrot:

Almost any twist, rigging error, or warp can be trimmed for. And many are never noticed in flight or trimming.

As for example, your difference in tail to wingtip measurement. Had you not measured it, you might never have known about it.

My C-3/10 twin has 1/4" difference in this same measurement, it makes no difference in flight.

In other words, get them as straight as you can, but unless you are trying for the ultimate airplane don't be overly concerned about minor discrepancies.

Bill.

Thanks guys im starting to feel better i was just really upset because i spent 75 on the kit plus building supplies and a new computer radio and servos got the total up to 400$ I sure hope you guys are right I have been bustin my arss over this plane trying to make it something to be proud of. all i got let to do is cover it and install the engine and radio stuff and it will be good to go maybe i can fly it sunday weather permitting.




The early bird catches the worm, but the second mouse gets the cheese

Foxtrot:

This is the one with the 1/4" difference - 11 years old and counting.

Bill.

Fox,

I am currently finishing my first kit as well, a 4 * 60, which is practically ready for covering. Upon reading the instructions in the kit on wing mounting, it hits exactly on the point you mentioned, and according to the instructions, it is not uncommon for one one wing-half to be slightly longer than the other wing-half upon completion of construction and joining of both halfs. In the case of the 4 * I am working on, what Sig suggests is marking the center of the Fuse in the front and also rear of the wing cradle. Measure the span of the wing, and mark the center on both the leading and trailing edge. Place wing on fuse, alligning marks on wing with those on fuse. Measure from wing tip to fuse end, if both measurements are same, your good to go. If they are differnt, keep the Leading edge mark alligned, and rotate the trailing edge until both measurements are the same, then remark wing trailing edge center. This should correct your problem. Hope this has helped.

I have an older scratch-built glider where I used stacked balsa between two plywood templates to make the wing ribs. Forgot that sanding the ribs also sanded the templates. One wing has a slightly smaller chord than the other wing. You can only tell if you lay the two wing panels together. Model flies nicely.

I've used more substantial materials for such templates ever since.

bax

Bax:

I use the same trick, but I use the odd numbered ribs for one side, and even numbered ones on the other. No noticeable difference that way.

Bill.

oooooh Bax you are a bigger man than me! i don't think i woulda told that one!! but heck everybody makes mistakes like that. i built a new wing for my pt 40 and it has a dowel to hold it into the fuse at the front....guess what if you don't glue that dowel in it lets the wing fly off!!!
don't ask how i know that!!!


john

the answer to all this is take your time and check/glue/measure everything at least twice before you call it done!!

Personly i dont think there is a model out there that is 100%, there are so many variables in the building that can change things, and ARF's are even worse ...

i wouldnt worry about it all, some guy at our field brought a plane down one day and it was a complete mess!! you could SEE the difference in the wing alignment and the tail was all over the shop but it flew like a damn angel LOL..

dont worry about enjoy your model have fun, get a devorce asap and start building bigger models

Yea im so excited about flying the se all i gotta do is put the covering on it and my new futaba 6xa and the servos for it should be here today. i am planning on flying it tomorrow, my luck it will be raining or sunny with 15 mph wind lol

Foxtrot, Man...that thing ain't gona fly! You let Mike iron on a piece of covering, now it jinxed for life, HA! I would tell him the piece he did caused it to warp!

my Kadet Mark II (newest plane lucky number 13) measures EXACTLY the same from glowplug to either side of H Stab but measures 1/4 inch or so off from left wing to left hStab and right wing to right Hstab but who cares, ill straiten the wings out and it will all be good, my old mustang was so grossly off that you could clearly see the difference, the garage door closed on the tail and moved the Hstab while Epoxy dried (about 1/2 inch) and its ok dont wory about it. as long as you built a good plane, it flies well and you did your best then you can look yourself in the miror and feel good (this is why i dont do ARF or RTF no satisfaction) dont kick yourself over it, no one else will. (be carfule with covering if this is your first time, covering masks NO flaws and actualy brings em out. sand it till you want to lay it next to you in bed like a teady bear ;-)). covering makes it or breaks it if the covering is nice, NO ONE (not even you) will notice tail.

-edit-

terible spelling, fixing the bad stuff.