BC12-65 Wing Rebuild

[Leenicklas]

Re: BC12-65 Wing Rebuild

I will take you up on your offer. I'll call you. thanks. Lee

[Leenicklas]

Re: BC12-65 Wing Rebuild

Probably a pretty stupid question, but is there "general instruction" anywhere how how to get started on building a wing. Spars are drilled, all fittings have been cleaned and primed and I'm ready to assemble. (I have a complete, intact wing to look at). Do I put spars on a couple of horses, start sliding on ribs, bolt in compression struts??????...................

[Hank Jarrett]

Re: BC12-65 Wing Rebuild

You have the first step, a wing to reference! You will probably run into several places where you have to back up a few steps because something should have gone on before what you already assembled. Be really careful slipping the ribs down the wing spars and get some Spackle paddles to slip between the flanges on the ribs where they rub the spar. Even a TINY burr on the ribs will catch on the wood and keep it from sliding down the rib. The scratches look like cracks and will drive the A&P or IA nuts when they see them through a little access hole after covering. I would WAIT to nail all the ribs until after everything else is in place (except teh LE skins!). You may need to move a rib a little to get a drag or anti drag wire in (or something not thought of at this time).
Basically the rule of thumb is everything has to go on the spars before anything else. ;-) I would think your second wing will go ten times faster than the first. HUGE learning curve.

Hank

[Mark Julicher]

Re: BC12-65 Wing Rebuild

Lee,
Sounds like you have the right idea! I like to use a 4x8 plywood table and block up the spars on the table, but saw horses are fine. I don't know of any written building sequence, but here goes from memory: Slide ribs on and double check. Install compression ribs and TRIPLE check. The compression ribs are not all the same length. Wrong compression rib at the wing root means lots of agony later on.
Snug up the drag wires but not fully tight. Hammer the LBNs (little bitty nails) into the rib flanges. Then trammel and final tighten the drag wires. After that goes fittings and leading edges.

[Hank Jarrett]

Re: BC12-65 Wing Rebuild

That sounds about right to me too (been a long time and it was a Cub wing), except you might want to wait to nail the ribs until AFTER you trammel the wing. The ribs really are just along for the ride as far as getting the spars straight. You will also need to move some ribs up or down a hair to get everything straight and level. Trammeling can pull the ribs out of position up and down on the spars.

Hank

[Guest]

Re: BC12-65 Wing Rebuild

Lee,
Sounds like you have the right idea! I like to use a 4x8 plywood table and block up the spars on the table, but saw horses are fine. I don't know of any written building sequence, but here goes from memory: Slide ribs on and double check. Install compression ribs and TRIPLE check. The compression ribs are not all the same length. Wrong compression rib at the wing root means lots of agony later on.
Snug up the drag wires but not fully tight. Hammer the LBNs (little bitty nails) into the rib flanges. Then trammel and final tighten the drag wires. After that goes fittings and leading edges.

Allow me to make suggestions.

Put the trailing edge on before you nail the ribs down and also install the aileron at that time.

That allows you to align the ribs and aileron hardware hardware such that you get a nice straight trailing edge that lines up with the aileron trailing edge and they both form one straight line.

The compression rib at the root and at the wing strut fittings are special.

They should be shorter especially at the strut fitting. Sometimes you have to grind a little bit off the foot to get the foot to fit ok in the strut fitting. The fit without grinding will put a slight bow in the compression tube because the foot edge rides up on the bend in the strut fitting.

There are shims to put at the end of the comp. struts in order to get the spars parallel (ie. same distance apart through out their length). They also get used to assure proper fit of the foot over the root fittings.

Save yourself a headache and carefully measure and compare the distance between the fuselage fittings and the root fittings for each wing and adjust the root fitting distance with shims so they fit on the plane before you do anything else.

Then when you think you're done put the wing on the airplane before you cover it to be sure that it fits nicely.

[Hank Jarrett]

Re: BC12-65 Wing Rebuild

I forgot about that! DEFINITELY put the wings on the fuselage before cover!!!! It is a WHOLE lot easier to fix a mistake without the fabric.

Hank

[Leenicklas]

Re: BC12-65 Wing Rebuild

Hank, et al, thanks so much for info. It is very helpful. One last question.......(that will be the day), in a previous thread re trammeling, reference is made to drag and anti-drag wires....there is a difference??

[Mark Julicher]

Re: BC12-65 Wing Rebuild


Drag wires hold the wing against drag i.e., flying forces.
Anti-Drag wires hold the wing against deceleration forces.
They look the same inside the wing and are often just called drag wires.

[Leenicklas]

Re: BC12-65 Wing Rebuild

got it. thanks

[Leenicklas]

Re: BC12-65 Wing Rebuild

"one last question", I Noted in the discussion that the compression struts are different length. I measured very carefully and determined 3 lengths: 29 31/32, 30 3/16, and 30 1/4. I assume that they are installed at the strut area, root area and other areas respectively. Part #'s B- A800, B 801, and B-A89 respectively. Any comments. thanks, Lee

[Guest]

Re: BC12-65 Wing Rebuild

"one last question", I Noted in the discussion that the compression struts are different length. I measured very carefully and determined 3 lengths: 29 31/32, 30 3/16, and 30 1/4. I assume that they are installed at the strut area, root area and other areas respectively. Part #'s B- A800, B 801, and B-A89 respectively. Any comments. thanks, Lee

Shortest one goes at the strut attach fitting

Next longest length goes at root

Longest goes everywhere else.

That's my story and I am sticking to it

Dave

[Leenicklas]

Re: BC12-65 Wing Rebuild

Thanks Dave....that't the way I plan to install them.l

[crispy critter]

Re: BC12-65 Wing Rebuild

Dave is correct

[Leenicklas]

Re: BC12-65 Wing Rebuild

It looks like I need one rib to finish right wing; the 4th in from the tip (counting the short rib on the end).
Plane is a '46 BC12D. book says rib is 1401-1R, 1402-1R and 1404-1R. Lee