West Coast,
Why would you have your wife blow dry it? Why not blow dry it yourself? If I asked my wife to blow dry my wing, she'd try to shove the dryer somewhere it shouldn't go.

It's called an incidence meter.
He needs his wifes help or he will have to grow another arm. You have to wet down the wood then hold and twist it while there is a heat sorce like a covering heat gun when trying to remove a warp. An extra set of hands really comes in handy. If it isn't too bad you can also remove a warp with the covering, sort of the same thing as the wet and heat but you twist one side of the wood and shrink the sag in the covering to straighten out the warp. Brian already mentioned that. It's something I have done a lot when I assemble ARFs for people, works pretty well too.

I get it. One guy can't do it alone. I'd ask anybody but my wife. She thinks I'm nuts building "toys" as she puts it. Okay, I can my hands on an incidence meter. Take a reading at the root and at the ends of the wings. Ideally they should all read identical. What is the most that the wing can be out and not worry about it? Thanks.

Brian, if you hold the wing at both ends and flex it, can you get the warp out of it with the flex?

As we know, wetting and drying is a standard method to remove or induce warp in wood, Gene above alludes to the fact it can be done with a interconnected/tied structure such as a wing, so you might as well give it a shot - but obviously only if you can easily remove the warp by flexing it while it's dry.

If you can get the warp out by flexing it, can you flex it a little more in an opposite warp? You'd probably want to bend it past the point of the warp, then as it dries occasionally loosen the flex to see how it's doing because you wouldn't want to induce opposite warp of what you already have.

I'd use a spray mist bottle to wet it. If you do try it, I'd be very careful about the amount of pressure when you flex it wet. I don't think soft wet balsa is something you'd want to really torque on. And if the warp is induced by the spar make sure that spar is totally soaked and hit the spar with the heat first and foremost. If you attached a vice grip to each opposite ends of the spar, does twisting the spar take out the warp? If so, maybe the spar is what you want to concentrate on.

Like I wrote before, this is a total bummer. I've never had a warp building (or maybe I have and didn't notice). I have my fingers crossed!

The incdence meter is the tool to best measure this. Eye-balling it is a way to see if you have a problem apart from the meter. Keep in mind that some wings do have wash out built into the outer wings. Mine is not supposed to.

Everything is very solid and does not allow for much flex at all. As suggested earlier, I think I would be best served by cutting the sheeting 9replacing it if necessary) at the TE glue joint to seperate the TE from the skin. I will seperate it a couple inches past the start of the warp on both sides. I'll put some fresh glue into it and do it better this time.

It was a good try. I think I like using CA for the skins better so far, but I have another Idea to try before I give up on the alaphatic glues for skinning. Too hard to explain, I'll just have to start a "Wing" thread and see how it works. It will mean buiding another wing, but it would be good to have a spare anyhow!

I have enough wood laying around to do this without spending a fortune on it.

In the meantime, I'm not giving up on my build, but have other responsibities to take on before I continue. Thanks for everyone's patience, and for keeping this thread alive!

Brian

And you should try to remove a warp from the bottom or the other side of the warp. Once a structure is sheeted it doesn't work very well. I haven't had a wing warp but I have had a couple of stabs take a set. I think I have made new ones as often as I have gotten the warp out. I keep a misting spray bottle in my shop mixed 50/50 with water and ammonia, this mix softens the wood pretty well.
With arfs I have removed the warps with the covering but these were not sheeted, just stick framed and sometimes in the hot sun they will return to the warp so it has to be done more then once.
When I sheet I use the thin CA on the one side and thick on the other but when I'm sheeting I get a CA reaction and sound like I have a cold for several days, that's why I wanted to know how the wood glue sheeting was going to work for Brian. I have to find a better way then the CA.

Grey Beard-

I have another idea , stay tuned!

Brian

I liked what Gene said, we'll wait for what you're doing. I'm currently continuing the build of a Proctor Fokker E.III Eindecker with a warped wing that a friend of mine was building before he died. I can un-warp the wing with the wing wires. The advantages of an Eindecker with wing warping.

Has anyone put an incidence meter on their wing?

I'm curious if it should stay at zero for the length of the wing.

Now that you mentione it, no!! There isn't any wash built in and mine were flat when I rocked them from side to side on my building board. I guess I could put one on but it would go from the center section to the tip only because after all these years my ailerons may have taken a set/warp??

Did you want me to do it and see how the wing is??

After I read about the meter, I got a hold of one and measured my wing from tip to tip. At the left wing tip I read zero. At the left wing root I read zero. At the right wing root, I read zero. At right wing tip I read + 1/2 degree. I was real happy with that.

Brian, I had nothing better going on, the wife is watching the never ending football game so I went out to the shop and zeroed my wing with the meter just at the outside of the aileron and zeroed the aileron too then ran my meter down the wing to the tips, it was zero all the way out from end to end on both sides.
Is that what you were wondering about? Checking to see if there was a wash or not?

Thanks guys. You answered my question. I was hoping for hope that this wasn't me. I did everything I could think of at the time to keep it straight. I think it was too much pressure with the iron.

I'm keeping my wing to fix it later, but I get so sick to look at it that I've decided to do it again. This time I will use thick CA to attach the skins.

I have the ribs cut out and have most of the other material that I need ready to go. So, starting this weekend, I will be going on my Extra wing, TAKE 2!

I know my board is flat, and I am going to piece the wing together in the order I prefer. There are only a few differences that will be noticed. Primarily:

1. I will be assembling a different LE. I will use 3/8 balsa tri stock as a LE cap strip.
2. I will secure the TE as per instructions.
3. I will skin the wing. Add Cap Strips.
4. I will put a centerline to my ribs, LE, and TE. They will line up before they get glued.
5. I'm debating on losing the 3 TE rib jigs and running a solid rib jig from center wing to wing tip (Just like the Ultra Sport).
This should keep the TE straighter then the 3 jigs supplied with the kit. If I were the Mfgr, I would make this mod or include rib jigs on every rib.
6. Apply the LE. Shape it with the proper contour.
7. Work smarter.

Any other suggestions?

bigal,

I bet that you'll probably never notice the 1/2 degree. I simply cannot settle for anything less than perfect. If I were building mine for personal pleasure alone, I would be happy with that as well.

I really want this airplane. Looking forward to flying it. There are a few vidoes on youtube that I saw that would be nice to share of this plane. They all have an in-flight camera on board. If I can, I see if they can get posted here.


Brian

Hi Brian,

I found the rib jigs to be quite ackward on the GP Extra as well. To do anything on the wing while it was standing on the jigs was virtually impossible so I tack glued the jigs to the tip ribs and that made it much easier.

Regarding your first wing, before you make a new wing...why not use your iron to remove the sheeting on the side with the warp then check to see if the warp is still there? If, as you think, the warp was pulled in when you applied the sheeting taking the sheeting off would remove the warp. You could then just reapply the sheeting (in whatever manner suits you best), less work than building a complete new wing and also will let you know if the warp was a result of the sheeting or rib notches too tight to the spar.

I'm planning to do this very thing. My concern ( and I'll never know until I acutally try) is that the TE warp may have affected the entire sheeting process, toward the LE. I may need to re-sheet the entire wing. With the extra glue involved, I'm a little concerned about the extra weight.

I'm not sure I understand. Are you suggesting the way the spar notches are cut may have twisted the wing?



I don't suppose I'm reveiling a neurosis of some kind? OCD maybe? [sm=72_72.gif]

Brian

When I assembled the wing, laying down the spar and fitting the ribs to the bottom spar all of the ribs tips were flat on the building board. After inserting the upper spar some of the rib tips lifted off the building board. I had to cut out one of the ribs and sand the notch in the rib slightly to get it to sit correctly. Had I proceeded to attach the TE without first re-seating the rib I would have inadvertently built in a warp.

Sounds as though your on the correct track there, I always use a meter when building a wing ,after I get the frame work done I'll block it up and measure the wing with a meter, if everything is ok I then proceed to the sheeting ,if its not I'll shim it so its past the point of being straight then sheet if its not to bad. if its to bad I will soak it and pin it past the point of flat and let dry recheck things and if eveythings a go then go to the sheeting.
1/2 a degree warp is nothing and you can easily take that much out with the covering and heat gun,I have pulled as much as a 1-1/2 degrees out just with the covering depending on the type of wing it is, But its tough to do and takes some time and as a rule 2 people. Make sure to wear some heavy gloves when doing this otherwise a burn or two can happen and fast.

Now if your building a fully sheeted wing your not going to be able to pull much out with the covering maybe 1/2 degree and thats a big maybe, those type of wings I want as straight as possible before I sheet.
Good luck Richard.

Big, a 1/2 degree out is nothing and like Cyber says, easy to correct with the covering, even if it's an older plane like mine you can still get that out but I'm sure no one flying the plane would ever notice it one way or another.
Brian is building his Extra to compete with so going for perfect is always the best way to go.
I don't have any photos on file of one of my Extra builds so I'm not 100% sure but it seems to me I made up a full length jig for the wing halves.
For sheeting the wing I use thin CA on the first side then either medium or thick on the other. I do have a CA problem but for sheeting I want it to set right away so I use it. This time of year I can have my shop window and door opened so it's not a real big deal but during the heat of summer or the cold of winter it gets me. The CA adds no moisture so that may have something to do with most of my builds not getting much in the way of warps. That was a MUCH tossed in there, let he who is wothout warps cast the first bottle of glue. Brian, how big of warp did you get??
Gene

I like a little warp. That way my plane can get warp speed. Live long and prosper.

Grey Beard-
My trusty Robart Incidence Meter is showing +1 degree on the left wingtip measured with the center of the wing at 0 degrees, and +1/2degree on the left wingtip.

I'll be using CA to glue the skins on this time!

I am now CONVINCED this is the way to go.

Brian

Water and heat won't unwarp 1 degree?? I think I would do it with the covering before I build another wing, if it didn't work out then I would build another one. I have over tightened covering and gotten more then that by accident and had to reheat and twist to remove it.

Ok.

Tomorrow morning I will spray it down and take the heat gun after it. I'll try it and see. If it works, then I will have a 2nd wing started for my spare extra then. [8D]

Brian.

After working with the iron, the heat gun, water, and muscle, I cannot seem to pull the warp out! Unfortunately, the iron method may work too well!

I did manage to split two ribs though.

I'll be starting a new wing this weekend.

Brian

I few replies ago I indicated I couldn't do flat spins with my 91FX powered GB 300. I wonder if my elevator throws were enough. On high rates I measured 3/4" up and down. Just finshed *****g them out to 1 1/4" up and down. Anybody that does do flat spins with this plane have measurements for their elevators?

PS: Don't know if anybody esles has had problems with tank preasure with this engine side mounted,but I solved my stalling problem a couple of years ago by pinching shut one of the exhaust tubes on my muffler.