Old new guy, starting over

[Bob A]

O.K., I've made a few posts here, four so far, of little consequence, but now I need to post something of importance - I think.

I finally got around to printing, taping together and cutting out the plans for the Mini Guinea. I then made a kit from Dollar Store foam board and built the plane, except or electronics, still waiting for the arrival of some servos. Big problem is, the trailing edge of the wing is approximately 3/8 to 1/2 inch ABOVE the fuselage!?! (Confused)

The ONLY thing I did in variance from the plans was to use a yard stick in place of the paint stire stick, it was wider then a stir stick but the same thickness. I did not allow for this variance by changing the airfoil indents on the inside of the wing before folding.

I see two choices;

1) Build a new wing; going to the hardware store and getting a "real" paint stir stick to use for the spar.

2) Slice the rear edge of the wing part way through, aft of the bottom sheeting (which would correspond to the aileron width) and re-glue it to be level with the bottom of the wing skin.

One way or the other should do the job admirably, giving me a 'flat' wing assembly.

Thoughts would be much appreciated.

Bob

 

[shephard101]

Hi Bob what a good explanation, but i am thinking about something, i do not know the cost and the price what so ever. Can you do the plane part via 3D printing? i think it might be a price to pay the 3d printer

 

[Hai-Lee]

Hi Bob, Bob here!

If your wing spar is too thick you can open the wing, (A hairdryer can be useful if you used hot melt glue), and then mark out and cut into the bottom or top sheeting of the wing to suit the width of the spar you used. I think the term would be recess. the spar can be cut into either sheet as the difference is small in performance though I prefer to do so in the bottom side of the wing for a better look. you only need to remove enough material so that the spar now arrears at the correct height.

If you spar is too wide you could open the wing and after removing the spar use a saw to reduce its width. Failing that you could make a spar of the correct width out of scrap FB and recess the wooden spar into the bottom sheeting of the wing. This gives the rigidity and the contact area required between the two score and fold lines in the top sheeting.

With the spar cut into one of the wing sheets the overall thickness of the wing could be as originally designed and problem solved assuming that your remaining parts are all cut out to the correct dimensions.

 

[Craftydan]

Bob,

So long as the two wing halves match . . .

Simple solution:

Shim the leading edge of the wing to bring the AoA back inline with the fuselage -- I'd shoot for gap between the fuse and LE and gap between fuse and TE be equal. Won't take much more than a popsicle stick to the leading edge, slid back. Dry fit, and when you're happy with where it sits, glue it on. Rubber-band it on and you should be fine.

you'll probably need to have a bit more up/down trim than "normal", but the FT folded wings aren't precise airfoils to begin with -- folding the wing a bit off of designed isn't disastrous . . . sometimes it's better . . . but folding two halves differently than each other, is bad, so if that's the case, it will need to be addressed.

 

[Bob A]

Thanks Everyone,

All good solutions but I don't know why I didn't think of CraftyDan's easy and simply solution of shimming the leading edge. All solutions will work but you can't beat simplicity.

Thank you everyone, I'll shim the leading edge and finish the plane from there.

Bob