Thanks for the suggestions. If I were to make these changes one at a time, which should I do first? I am afraid of it not staying out on the end of the lines.
Also, I live in the South Central Pennsylvania near the Maryland line. There is a very fine flier in Hagerstown, Maryland. I am contacting him for some help in trimming. He actually flies at a club field in Chambersburg, PA. Hagerstown is only 20 miles away. I'm near the North South corridor of Rt. 81. I live in Mercersburg, PA.
Thanks for the help. I'm about to try some of these suggestions.
First and foremost, *get rid of that rudder offset*! Excess offset tends to cause exactly the problem you describe. Even the stock arrangement of airfoiled fin with significant offset is *way too much* for clean flying, but additional rudder tab will be catastrophic. Don't cut off the fin to get it straight, just ensure that you have no more than the stock system.
If it's otherwise straight, a decent CG position, and you have sufficient tipweight, there should be no problem with line tension.
But before you fly again, be sure and check some critical parameters. First, check the alignment of the wing and tail. Measure from hingeline to hingeline at the tips of the stabilizer. It should measure the same on both sides, i.e. the hingelines should be parallel to each other. If they are skewed more than about 1/16" out, you will have some problems. Then check that the wing and tail are parallel to each other in "tilt". Sight it from behind, and if one stab tip is higher relative to the other, you need to fix it. To fix the tilt or small amounts of "skew", you can use the boiling water and towels trick. For significant amounts of skew you may have to cut the stabilizer loose skew it over straight, and then re-glue.
While you are checking for the stabilizer being tilted, also check the wing and flaps for warps. Hold hte airplane up by the tail and sight along the trailing edge of the wing. Tilt it up or down until the trailing edge of the wing is centered at the root. Then, without moving, sight along the trailing edge to the tips. If it's centered at the wing root, and not centered at the tips, you have a warp and you need to straighten it out. Same thing with the the flaps. If it's an iron-on, you can try reheating the covering with a heat gun and twisting (although if it's built crooked you will have a problem fighting that mighty D-tube with only monokote. If it's silkspan/dope, you are probably going to have to use the boiling water and towel trick.
Also check that the engine is either straight ahead, or slightly pointed to the right. If you can see it with your eye when you look, that's enough.
Also check the center of gravity. To start, balance it so that the airplane balances about 1/2" behind the leading edge at the tips. This is probably not ideal, but it's certainly safe until the rest of it gets sorted out. It also ensures that the leadouts are at least in a safe place. It doesn't matter how much weight you might have to add, just put it in there.
When you get to the field, attach the lines, and then hold the airplane by the spinner and tip of the fin, so it can roll. With the lines attached, the outboard wing should drop distinctly. If not, add tipweight until it does. It should probably lean about 10 degrees to the right with about 5 feet of line suspended in the air. Once again, this may well be too much, but it will be safe.
You should be using .015x60 stranded lines to start. No way should they need to be as short as 52 unless you are on oversize lines. With either engine you should be trying to start with about 5 second laps- once again, probably faster than necessary if everything is perfect but until you get it perfect you need to get it safe. Forget the old BS that people used to toss around about 6-6.5-7 second laps. It got slower every time they told the story. I can fly 6 second laps and get through patterns, did it at the NATs one year, but it's not going to get you decent performance and my airplane is in very good trim.
A lot of this needs to be done before you even try again. If everything is set as shown, it will pull like a tractor, in level flight, at least. When you do fly it, you have a very good idea to go out with an expert and have them look it over. There's so many simple things to check that will pretty much guarantee success, but you may miss them when describing it to us.
Brett
Topic: Cranky Flying Nobler (Read 2760 times)