Every plane launches different. EG The Shadow has the tow hook 1/4" behind the CG My Extreme has it right on the CG My Stork has it 1/8" in front with 1/16" of down trim and 3/4" flap and 1/4" camber.
Most of my pop offs were at the point where I started pulsing the winch. The second I took my foot off the pedal the plane would fly off. I had to learn to stay on the pedal a bit longer and tap very quickly even if it looked like I was in trouble. It also sounds like it comes off during rotation sometimes. Try keeping the nose up and toss it up instead of forward after you build some tension. I think most of your problem would be solved with a bit of down elevator. If you don't have elevator trim in launch mode, then use your slider to put it in. You can always slide it back to neutral after zoom. Tom > > <I am flying (or possibly more correctly, trying to fly) a high quality open > class TD ship (no names as it has nothing to do with that). It really is an > excellent flyer, when I can get it in the air. However, in the many months > that I have had it, I've had about 75% of my launches end in pop-offs. I am > fast reaching a point of total disgust. I must be doing something wrong but > have not a clue as to what. The guys in the club are helping all they can > but we're not making any progress. > > The spec calls for a 5-1/6" CG (from LE) with a conservative position being > 5-1/16". I started out there and over time I ended up with the CG at 4-7/8" > with the tow hook about 1/4" in front of that. Getting tired of the > pop-offs, I decided to start over again. I moved the CG back to 5-1/6" and > the tow hook has been moved back as well. The tow hook, being 1/4" to 3/8" > in front of the CG is probably further ahead than it should be but I would > expect that to flatten the launch. If anything, the launching has gotten > worse. > > I use a 'launch mode' but do not any elevator adjustment in that mode. I > have tried my launch mode with... > > -flaps only, more flaps, more flaps > -flaps with a touch of aileron camber > -flaps and ailerons cambered together, more, more > -flaps with a little less aileron than flap. > > No matter what I do, the plane seems to launch with the nose too high and > almost always pops off at some point (usually at a lower height but sometime > when it starts to arc over). The only elevator I add during the launch, if > any, is a little down in some sort of vain effort to prevent the nearly > inevitable pop off. > > I even get a popoff some of the time with a full pedal launch. > > HELP! > Dave> > > RCSE-List facilities provided by Model Airplane News. Send "subscribe" and "unsubscribe" requests to [EMAIL PROTECTED] > > RCSE-List facilities provided by Model Airplane News. Send "subscribe" and "unsubscribe" requests to [EMAIL PROTECTED]
