Taping hinge lines

[Brad Smith]

I read alot about taping hinge lines what kind of tape do you use and how do you do this? Do you allso tape the elavator too?

[Brett Buck]

I read alot about taping hinge lines what kind of tape do you use and how do you do this? Do you allso tape the elavator too?

    You do both. I wouldn't bother even test flying it without, do it before the first flight. For the technique, see this post (among many others):

http://stunthanger.com/smf/index.php?topic=11355.msg99465#msg99465

    Brett

[Tim Wescott]

    You do both. I wouldn't bother even test flying it without, do it before the first flight. For the technique, see this post (among many others):

http://stunthanger.com/smf/index.php?topic=11355.msg99465#msg99465

    Brett

What Brett said, except there's a lot of room between the "rocket science" quality job that he describes and useless, at least if you're not going for 20 appearance points.

In my experience it can be a little ugly both visually and audibly and still work fine.  It'll fall of its own weight while giving an audible crackle (and the crackle fades right out after it gets a mist of castor oil on the hinge line).  I'll pass the job if the surface will still flop around on its own weight, unless I'm looking for "pretty".

[Brad Smith]

Do you tape the bottom or top or does it matter?

[Hoss Cain]

Do you tape the bottom or top or does it matter?

This has been discussed before on this forum so I am sure that I will get some BOO TO YOU replies. However while RC may be taboo here, RC modelers have developed many items that really assist in keeping good control of a model. Sealing hinge lines is one of the best.

1. Using any tape you wish or "money-kote"  (or like material)-- everything I have used has to be replaced now and then - tape all hinge lines on the bottom. Most flying is topside up, so bottom saves some oil from creeping into the seal. Crease the material into the hinge line along with the hinges as well as you can. Keep some play there for keeping slack when the surface is moved opposite the bottom.
2. When an airplane is maneuvering in a loaded maneuver, air can escape from one side to the other. This changes the airflow for maybe just a microsecond which can cause a jolt to the maneuver. You don't see Pattern or IMAC or even most Pylon Racers fail to seal surfaces.
3. When I was rather new in RC (early '70s I did not worry about this) but I learned. One person that I came to know was one Mr. DON LOWE. When on the AMA EC we seldom agreed on anything, however IMO, Don was the MASTER on any form of RC or any other aerodynamics. You could well take his advice to the model airplane BANK!
4. Don's main item was to SEAL the control surfaces. Once I started doing so, my airplanes learned to fly much better. I wish I had had such knowledge when I was a CL stunt competitor. George Aldrich said to keep the flaps snug. Back then we used cloth hinges and that certainly helped, especially if properly done. Still sealing the hinge line will stop air drifting through and save many a "bubble" from being there.  Any bubble, even elevator, can create a bubble that will cause a change even if just a short back and forth shift of the longitudinal axis and possibly an accident, much less just a poor maneuver.

Of course YOUR CHOICE and there will be the usual NO-NOs with their inputs. However as a kid and  I was told by my Mom when I did not want to take my coat to school, "It's better to HAVE it, and NOT NEED it, than to NEED it and NOT HAVE it.

SEAL the HINGE LINES.

[Brett Buck]

Do you tape the bottom or top or does it matter?

  It doesn't matter for performance, but everyone does it on the bottom because of appearance.

     Brett

[Brett Buck]

Crease the material into the hinge line along with the hinges as well as you can. Keep some play there for keeping slack when the surface is moved opposite the bottom.

     This is workable for RC but you need to have much less drag on the controls for a stunt plane. You always have the entire torque of the servo to move the surface and it will always move the distance you want because of the feedback loop. In stunt you can have very little torque available at times, and if it's draggy it will move less than desired (and differently depending on the airspeed, etc).   It needs to pass straight across the hinge line in line with the pins, in which case there is no slack or anything else that compresses or expands the material. The hinge line needs to be configured to permit this when you build it.

     Any sort of sticky tape will work but Trim Monokote, FasCal, etc, will leave residue behind when you remove it, because the adhesive will stick to the paint better than it sticks to the tape. And it will tend to pull up the paint. The Scotch Crystal Clear/Multi-Purpose tape, and the Moore tape that Ted uses, doesn't have nearly that tendency. Usually it pulls right off. Either of them stays "soft" over time so it has little tendency to crack and lasts a very long time.

    Brett

[john e. holliday]

Do it the easy way and go with cloth hinges full length on both surfaces to begin with.   It means you wont get that 20 points for appearence, but you don't have to worry about what tape to use.   Just finished the elevator/stab on my next secret fun fly plane in 1/4 of the time it would take to do nylon pinned hinges.  Pictures further down the road.

[Mike Griffin]

Guess Doc and I are the Dinosaurs but I use cloth hinges and apply them the full span.  But I am not a competing Stunt flyer and am not after appearance points. 

Mike

[Dean Pappas]

Hello Brad, Hello All,
I have to think that a well-done classic cloth hinge job is worth more points on appearance day. I could be wrong.
In any case, the most bind-free way to do hinge taping is to take two pieces of either the flexible tape everyone has been describing or monokote and attach two strips to each other stick-tosticky side with only 1/8" overlap.
This gives you a strip that gets cut into "fits between the hinges" lengths and then gets adhered like an "S" to the fixed and movable surfaces. One is attached on top and the other on the bottom.
You can cut the excess off so that no tape comes out of the hingeline at all.

For pictures, let me suggest you go to the Mineral Area Model Associaton's website wwwrcmama.com and go to their library. In there, there is a copy of an article I did for MA about basic RC trimming (yeah I know!) but in one of the three parts there are some explanatory drawings. I think it's part 3, but I won't swear to it.

Brett is absolutely right. It's that simple.

Regards,
  Dean Pappas