Hog Head

Hello. I decided to try building rather than assembling an ARF. I chose the Tower Fun-51 as it seemed like an easy first kit. I built the wing over the plans as instructed. When I finished the bottom of the wing it was straight and free of any warp or twist. I then removed the wing from the board and proceeded to sheet the top as instructed. After the front half and trailing edges were sheeted I noticed that the wing now had some twist to it. As this is my first kit, I am not sure how to proceed. Can anyone out there help me? Thank you, Gene

2slow2matter

My Feedback: (1)

Now, repeat after me....I will always build on the board, I will always build on the board, I will always build on the board, I will.............................................. .....................................

2slow2matter

My Feedback: (1)

Just kiddin, don't listen to me, I've only built some tail feathers, and that took me 5 hours! (but, they are straight). You might have to debond the sheeting, and start over. My guess is when you were sheeting it (off of the board), you were holding it with a little twist, and the sheeting locked that twist into it. It's not a problem to de-bond the CA (if that's what you used), it just takes a while. Get some debonder and squirt over the joints where the sheeting is glued to the ribs and edges, and let it soak in for a little while, then work it off. That's the only way I know to fix it. Someone else may have a better idea....

Hog Head

Thanks for the reply 2slow. I had thought about the debonder but the wing is completed and I have no way to get to the ribs unles I were to cut away the sheeting. The first side was completed on the board but i held the wing in my hand as I sheeted the top side. Hints? Thanks, Gene

bryris

Do a search on here......there are some techniquies to gently warp the wing back to straight. I am not sure what they are, but I KNOW that I have seen them on here.

Hog Head

Thanks bryris. I'll give the search a try.

ksechler

I have bad news for you. Your plane isn't going to fly to well with a warped wing. It's also next to impossible to straighten it out. My advice to you is to bite the bullet and remove the sheeting and reglue. It's a pain in the neck, but you'll be glad you did. As an example I built a Fly Baby and warped the wing. The thing flies like crap. I've never been happy with it and don't even fly it now.

dicknadine

you might try cutting slices, approx 1/16 wide, length wing of wing.apply liberal coating of ammonia water, twist the wing to a little over flat and see what happens. let dry, then fill in the tapered voids with new sheeting, while its over twisted. has worked a couple of times for me. beats removing the compelet sheeting and starting all over again. dick

Hog Head

Well, I bit the bullet and removed the sheeting from the top of the wing and it's magically straight again.

smedsky

Congratulations. You have already learned more than an ARF will ever teach you.

Hog Head

And indeed I did. This time. I removed the top sheeting which had warped the wing after I posted this question. Well, actually I warped the wing not the sheeting. Anyway, after 2 weeks I finally re-sheeted the top, pinned to the board this time instead of in my hand, and the wing came out as straighter than an arrow. Just wanted to thank everyone for the help. Now to finish the plane and fly it if the weather ever lets up here. Thanks again, Gene

TnT3

I have a similiar problem, but i dont have a twist but i do have a gradual curve in the middle of wing, i built it on the board and i noticed the wow before i sheeted, I only have one side done and sheeted and i noticed the main spar on the reverse side has a gradual curve to it. Right now i have the middle blocked up a bit, soaked it with amonia water and put weights on the ends, took the curve out with the weight so i'm going to let it dry like this. When i put the main spar on the reverse side i'm going to install it with the curve going the opposite way and hope this straightens it out a bit. Will this work?

tschuy

My Feedback: (1)

Alway, Always sheet your wings while pinned or weighted to your building board. Also be sure that your building board is straight. I've built wings that have a span as much as 11' and never had a problem so long as my wing had been pinned or weighted down. With careful checks of my building board they've came out straight as an arrow. But as stated earlier in this post you learned a very valuable lesson which hopefully will carry on to your next build. Most building instructions that come with the kits these days have good idea's or instruction on how to sheet your wings and keep them straight. The next gotcha that you might run into is seeing your wing warp again while ironing on your covering. Take your time and be careful when getting your covering material on and heating it to get it taught. If your not careful it'll warp in a New York minute. But in this case it is recoverable by simply heating the skin and twisting it back straight and hold it while letting it cool. A good technique that I like to use is to rubber band two arrow shafts to the wing running from the leading edge to the trailing edge(not span wise). I'll put one at the root of the wing and then another at the tip of the wing. Stand back about 3 feet back from the wing tip and see if they if they run parallel or evenly matched with each other. If not then you got a twist that needs to be sorted out. this works pretty slick with a flat bottom wing but you might have to manufacture some blocks if working with a semi-symmetrical airfoil. Reason I state the above is that I ran into this one time and nearly lost my airplane due to my ignorance. A check suggestion from an expert got me pointed in the right direction and since then have not had a problem.

Hope this helps....

Cheers,

superflea

often times a warp can be brought out of a wing, if its not too bad either by misting water on it then placing it back on the board FLAT and weighing it down FLAT untill all the water has dried say a day or two, we all know water will warp balsa and it is possible to control the warp with 30 lbs of weight evenly distributed on the panel. option no.2 again if its not too bad is to twist the wing back into shape when applying the covering, monokote etc. is very strong and can remove some fairly impressive twists ( dont ask). for this reason you will need to work carefully when covering to make sure the finnished product is still flat and true.

i know this post is a little late but food for thought for next time.

RCPAUL

My Feedback: (1)

Glad things worked out.


However, this kit has other problems. When building the fuse with the soft ply provided, the soft ply is not 1/8 inch as implied - it is metric. When laminated it is not 1/4 inch as the rest of the balsa but 1/32 thinner. Thus, when gluing the siding, it does not glue on one side to the ply - and, there have been several reports of the fuse breaking behind the wing in flight.

Beware. sand the fuse to the ply before sheeting.

Also, landing gear area is weak.


Paul

cmartin3d

I just bought a Tower Fun 51 kit offline and the suggested engine range is .35 - .50. The engine I had in mind for this plane was an O.S. .46AX, However, I have been hearing reports that this is way too much powerplant for this model. Ideally, I want EXTRA power to get out of scary 3D situations, but i don't want to hover at 1/4 throttle. Please, someone who own's this plane reply to me before I buy this engine. Thanx.

mcarleno

I would stick with the OS.46AX on this plane. We have one at the field and its pretty close in weight and wing to my Uproar (the Uproar doesn't have enough vertical surface for very good 3D though). I would prop this engine on this plane with an APC 12.25x3.75. Keep it nice and slow with a lot of usable thrust, makes climbs great!