oddy

Hi Everyone

Im trying to do some experimentation with different Q40 airfoils, for which I want to build some Foam/Balsa Q40 wings.
(Concient that this building technique will not allow me to have a perfect finishing for evaluating the full potential of each airfoil)

I have the following questions.

1.- Each Foam Core (Left & Right) are supposed to be planked and then center glued or foam cores are supposed to be joined together first and then planked????

2.- They are supposed to be reinforced both with Carbon Fiber all along the wingspan and a balsa/Triplay spar at the center of the wing.

3.- How many Layers of Fiberglass cloth at the center section?

Thanks in advance for your help, any advice on this kind of wings construction will be highly appreciated.

Victor Arreola.

Ed Smith

I build my own Q40s. I use foam core wings. Step by step this is what I do.

I cut the cores.

I make up four skins. I glue the edges of the sheets with a glue that sands well. The edges of the sheets are not always the exactsame thickness. When the glue has dried I use an orbital sander and sand both sides of all the sheets smooth. It does not take much to do this.

I apply the skins t the cores with epoxy resin and vacuum bag. When applying the skins I add a 1" strip of 2oz cloth under the top and bottom skin at the trailing edge. This gives me a stiff hard edge so I can sand the trailing edge to a sharp profile.

When this stage has all cured I trim excess and add Leading edge and tips.

I sand each half and finish completely. I then join the two halves with an incidence meter on each tip.

I fit wing screw dowels.

I install a wingspar in each half with a centre joiner. the spar positon is at the high point of the wing.The spar is 1/8 liteply with Carbon tow glued both sides. each spar is 15" long. From the bottom I cut a slot for the spar fulll depth to the underside of the top skin. I do one side first, when this has cured I do the other. I then fill and smooth the groove.

If there is a wing mounted landing gear I fit the mounting plates with blind nuts in place. They are 1/8 ply and are glued to the leading edge and spar. The plates are over size. I fill the cavity with a balsa plate thick enough to be sanded flush with the underside airfoil


I glass the top and bottom of the wing all at once. I use the gapless hinge style of aileron, I lay on a pice of 2oz cloth across the centre section just wider than the wing saddle. I lay on a second layer of the same cloth wide enough to cover the landing gear positions and to the inner end of the ailerons. I lay two strips of 2oz from the edge od the second layer to the tips. This is wide enough to create the aileron hinge and overlaps the trailing edge. Apart from the hinge cloth I repeat for the bottom surface. I glass over everything with 3/4 oz cloth and vacuum bag.


I fit the aileron torque rods. Fill and smooth the grooves.

I very carefull cut the underside of the ailerons up to the underside of the top glass hinge material. I clear th aileron leading edge with enough angle to allow for the desired down movement.

I locate the landing gear mounts and fit the landing gear.

The wing is now ready for final sand and prime/paint

oddy

Ed thank you very much for such a detailed explanation,

This will be of great help for me.

Victor Arreola.

rmenke

My Feedback: (13)

Ed:

Very nice work!!!!!!!!!!!!!!!!!!!!!!

[email protected]

Ed, You have written a very good instruction sheet for a foam wing assembly-very clear and should be easy for anyone to follow. thankyou............look forward to seeing you soon at Muncie, regards trevor Henderson

Ed Smith

Hi Trevor,

Thanks for the kind words.

I will be in Muncie as a spectator. I will sit back in the shade with the appropriate refreshment and watch everybody else beat themselves to death.

Ed S

[email protected]

perhaps I had better bring you some duty free coolant............how good is the coke? Trevor H

Kevin Matney

My Feedback: (1)

I'm working on a photo DVD of how to do a wood wing in a Q/500 and Q/40.
What do you think it is worth????? The pics are in Hi res

[email protected]

a couple of bottles of rum.....................trevor h[&:]

Scorpion Racing

Hey ED Smith,
Have you ever heard of a QM 40 called the "Foxy Lady"? I happen to have a Fuse, Tail and set of foam cores for one and I was wondering about the wing construction. The plans say the drawing is for the standard wing, what is the difference for the competition wing? I thought you would be the one to ask since your name is on the plans!!

Kevin Matney

My Feedback: (1)

That plane was Danny Kane call him.

garys

Actually, Harold Sattler's Miss Candace was originally called the Foxy Lady, which is probably what he's referring to.

Scorpion Racing

You are correct, Gary, I got the glass fuse and tail from H&R with a set of foam cores a couple of years ago. The plans say "Foxy Lady" and is crossed thru and says Miss Candace. On the plot stamp on the lower right side of the title block it has the file location on Ed Smiths computer, or at least in a file called Ed Smith, for the file. That is what I am refering to.

Anyways, should I just build the wing as described above?

Thanks,

Ed Smith

There is no mystery here, The Foxy Lady was produced before the Miss Candace. It was one of Harolds, early products. It had a glass fuselage and built up wing and tail surfaces. Harold then produced a composite wing for it. He used the same plans that I drew. The Foxy Lady was superceded by the all composite Miss Candace, I am not sure if it includes a set of plans now.

Ed S

Scorpion Racing

So Ed, the plans say the drawing is for the standard wing, what is the difference for the competition wing?

Thanks,

Ed Smith

The plan does not say anything about a "Competition" wing. It says "Composite" wing. If you have a set of wing cores then you need a plan to finish the wing. For those that purchased a composite wing, the wing is built so a plan is hardly needed. There have been many updates to the original Foxy Lady design to what is now the Miss Candace. Once H&M offered the all composite kit the built up version was no longered available and plans were no longer updated. The latest Miss Candace has a different airfoil, wing planform, a shorter nose and a larger vertical stab.
The plan you have must go back about six or seven years, there is even reference to the Q40 with a backplate mount so that gives you some idea of how old they are.

Ed S

sahartman21

Ed,

I still have a couple questions about the gapless hinges. I may try on my Proud Birds.

The following is from discussion earlier: Questions are in the text

I glass the top and bottom of the wing all at once. I use the gapless hinge style of aileron, I lay on a piece of 2oz cloth across the centre section just wider than the wing saddle. I lay on a second layer of the same cloth wide enough to cover the landing gear positions and to the inner end of the ailerons. I lay two strips of 2oz from the edge od the second layer to the tips.

SAH - So 2 layers of 2 ounce glass are used for the hinge. One layer is not heavy enough?

This is wide enough to create the aileron hinge and overlaps the trailing edge. Apart from the hinge cloth I repeat for the bottom surface. I glass over everything with 3/4 oz cloth and vacuum bag.

SAH - Per our earlier discussion you put the wing between layers of peel ply and use a breather cloth. I've been using polyester fabric for peel ply and a paper towel for breather cloth. I suspect this should be fine?

I fit the aileron torque rods. Fill and smooth the grooves.

SAH - Do you apply fiberglass over the torque rods or not mess with it?

I very carefull cut the underside of the ailerons up to the underside of the top glass hinge material. I clear th aileron leading edge with enough angle to allow for the desired down movement.

SAH - Some methods add some balsa to cover the foam that is exposed after cutting the hinge. It looks like covering the foam is not needed?
Thanks for your comments earlier!

[8D]

Ed Smith

It seems I have to remember what I said in 2007!.

The two strips of 2oz cloth statement is a little misleading. That is one strip on each wing. The hinge is actualy one piece of 2 oz cloth plust the 3/4 ounce finishing cloth.

The peel ply and breather cloth is very wastefull of material. I ran out of breather cloth so I started to use paper towels. Provided there is not an excess of resin the paper towels proved adequate. Even if the towel got saturated the resin did not stick to the nylon bag.

I put the torque rods in a brass tube and glue that in place. I once tried waxing the actual torque rod and embedding that in epoxy. Needless to say it would not release. I had to cut it all out and start again. Something to think about. With gapless hinges the actual centre/pivot of the hinge is right on the top skin. Now think about this. For the torque rod to operate properly half of it should be above the top skin. With the rod below the top skin it is actualy rotating around the pivot point. If the rod is fixed right up to the aileron inboard end it will not work. It will be too stiff. Therefore the rod cannot be fixd in place for a couple of inches at least at the aileron end. This allows the rod to flex as the aileron moves. This works only with Q40 type ailerons. The aileron deflection is so small (3/16" max up and down?) that we get away with it. I hope I explained that clearly.

Performance Specialties used to sell a very thin tape for sealing the control surface gap. I would lift the control surface, apply the tape and then "Tuck" it into the gap as the control surface closed. On most of the composite wings etc I see now the underside is cut at an angle so the gap is always closed as the surface moves.



I think I covered it all, if not let me know.

Regards.

Ed S

sahartman21

Thanks Ed,

I got to looking at different ways people installed a gapless hinge. The method described above sounds relatively easy to install.

Scott Hartman

GSJames

I made my first skin hinges last week. I used the method described by Dave Norman on the NMPRA website. It worked well. I used the Crisco trick and the torque rods released easily. Also, I tried two different methods to cut the 0.010" recess for the pre-cured glass. On one wing panel, I used the "sanding block tool" described by Dave and on the other, I used the Dremel Moto-tool router method described by AJ Seaholm on his Seeker build thread. Both methods worked, but I had better success and a cleaner looking result with the router method. The 0.010" glass hinge is a little "stiff", I'm wondering if 0.005" would work a little better. Of course, the stiffness helps prevent aileron flutter, so that's a plus. The offset pivot axis is a little weird, but it appears to work. I'm ready to paint, so I'll know the final results in a week or so after maiden flight.

Scorpion Racing

Gary,
I also use Dave Normans method on the ailerons with the .005 thick material in 424, and it has been fine for that speed. If you make the hinge material strip about 1/2" longer on the ends so it extends beyond the surface, it will have less tendency to try to peel off. I think Dave mentioned that a couple of years ago in a thread somewhere! I have also been using the thin Mylar tape for sailplane wings on the underside of the wing to seal the gaps. It has tape on the front 1/2 of the strip to bond to the wing, and the back 1/2 (with no tape) hangs over the aileron. I think you could do something similar with gluing a strip of the .005 fiberglass on the bottom to seal the gap, and I am going to try it out on my next wings.

fizzwater2

My Feedback: (61)

Scott - that tape sounds interesting ( the sailplane tape) - where do you find it?

daven

My Feedback: (1)

Gap Seal,

Heres a link.

http://www.nesail.com/detail.php?productID=1152

I've used it, its kinda thick, but works good.

GSJames

Thanks for the info, Scott. It's good to know that the 0.005" will work well. I also did the bottom of the wing like Dave wrote in the NMPRA article using 0.010 that covers most of the bottom gap but leaves a 1/8" gap with an overhanging "lip" between the aileron and wing. The 0.005 hangs over that gap and Dave said that he used the sailplane tape, sticky part on the aileron and the mylar going under the "lip" forming a seal. I haven't applied the sailplane tape yet and right now, the edge of the aileron is hanging up on the 0.010 lip. I think that after the tape is on, it will work better. However, I think that a simple 0.005 piece that is glued to the wing and simply slides over the aileron (about 3/8" inch or so) would be an easier solution, after all the gap is already sealed for air leaks, we are just smoothing out the cavity on the lower surface.

I'm a little confused about your comment about making the strip about 1/2" longer on the ends so it extends beyond the surface. I assume that you mean ONLY on the part that is glued to the wing. If you did it all the way across the aileron, then the aileron wouldn't move... Perhaps I am misunderstanding what you mean?

I want to express my thanks to Dave Norman for the help he has given me. In February, I was in MSP doing my annual checkride in the A320 simulator and Dave let me come over and visit for an afternoon. My learning curve went STRAIGHT UP! In that afternoon, l learned what it would have taken years to figure out on my own. Thanks, Dave!

Scorpion Racing

Sorry about the long delay, work sometimes gets in the way!! The stuff Dave posted the link is the same stuff I use, but I bought my last batch from Hobby Lobby. The strip I use on the aileron is about 11"wide x1 1/4" long. My ailerons are 10" x 1 1/4", so the strip DOES hang over the wing beyond the ailerons. After you glue the strips down (I then glass the entire wing with .5 oz. cloth after I do the ailerons) I use a razor saw and cut the aileron ends loose, which leaves some of the material beyond the ailerons. What this creates is a "C" shape of material around the aileron (with the aileron attached to the sheet between the "C"), and the additional hinge material helps keep it from peeling off under the stress of flexing. If the hinge material is the same size as the aileron, the corners tend to come loose over time.

I hope that explanation makes sense!!