Problem with LT-40 Build
 

I just starting building an LT-40 for my father's birthday coming up. I came to a problem at the beginning of the build. When I went to line up the trailing edge with the ribs marked on the plan, the slots are off. I took pictures to show you all what I mean. I line them up by the sheeting I just glued in, and then the spacing gets progressively worse as I get to the wing tip. I'm really hoping it's something simple that I'm overlooking...

I reread the note by this section in the instructions, and also tried to flatten my plans out, and there's still some gap. So... that last notch is still over hanging the last rib placement... where do I go from here?

RE: Problem with LT-40 Build
 

Not too bad...I would make sure I built the ribs as perpendicular, square and parrallel as possible. The spacing will only be a problem at the tip end. There you can either renotch the trailing edge - probably my choice- or you can put the rib in the current notch and put in a little piece to fill the space at the ends of the other spars. It is not uncommon for plans to shrink occasionally, sometimes unevenly. The other thing I would check is to place the other trailinng edge over the one you have on the plans as best you can and 'eyball' the position of the notchs on that one. Then go for the best symmetry that you can. Good luck, let us know what you do. 1 other real minor tip. When I pin wood down, I push the pins into the board on the opposite angle, so the pins hold down the top edge of the wood. Have fun! Doc

RE: Problem with LT-40 Build
 

I ran into this to on mine. What I did was make sure each leading edge were thesame that the slots were cut the same. On mine they were so I just placed the ribs to match the leading edge. Instead of a 70 in wing I ended up with a 70 1/4 in.
My plans were right on in the center section of the wing. Just the last few ribs were off, and they were off the same way on both wings, so I just let the leading edge be my rib spacing guide towards the wing tips, work fine and no extra cuyying.

RE: Problem with LT-40 Build
 

MadDriver,
Have you read over my LT-40 build thread? It might help you with getting through these spots. Your can find the thread here: [link=http://www.rcuniverse.com/forum/m_3439708/tm.htm]Pay It Forward build thread!! LT-40 build.[/link]

Here is the specific post in the thread where I dealt with this step [link]http://www.rcuniverse.com/forum/fb.asp?m=3459127[/link]

There is a warning printed out in the instruction manual that says the slots in the trailing edge are correct because the plans can shrink or expand. Read through my build to see how to deal with it.

Ken

RE: Problem with LT-40 Build
 

Thanks for the replys. I'm still confused though. Should I line up the last notch with the rib at the wingtip, and then build from that? And RCKen, your thread is the reason why I bought this plane. I figured it would be a quick, easy build with all the information you have given us. I saw your post about this, but maybe I didn't read through it too well, because I was still confused when I got to this direction.

RE: Problem with LT-40 Build
 

Actually, that might just be the way to go. Do as you suggested and line the slots in the TE (trailing edge) with the ribs on the plan. If they all ribs on the plan line up with the slots in the TE then you should be ok. Just make sure the the ends of the TE stock are ok on both ends. You can cut off any excess that you may have. But if the stock is too short on either end then you can't do it like that.


Ken

RE: Problem with LT-40 Build
 

Ok, that's the way I did. It's looking good so far. Even though there is that amazing build thread already for this plane, I think I may start one of my own just for my sake... maybe people will tell me what I'm doing wrong and how to fix it! :D I'm going to get a little further along in the build before I start posting pictures though.

RE: Problem with LT-40 Build
 

Sorry Maddriver, I meant TE not LE. I`ve got 4 builds going in different stages. and it gets a little confusing at times.
Follow RCKen`s, building thread, it don`t get much better than that.
Good luck with your build.

RE: Problem with LT-40 Build
 

I ran into similar issues. I left the lower spars, and TE a bit long. I used the TE for spacing the ribs. Once the final rib was in place, I cut the lower spars to length. Then after adding the wing tip piece, I cut the TE and LE.

Remember, you can always cut it shorter, but you can stretch it longer...