WattFlyer RC Electric Flight Forums - Discuss radio control eflight - View Single Post - Build Thread; Mountain Models QF-2 DLG
View Single Post
Old 04-28-2010, 11:53 AM
  #116  
Sky Sharkster
Super Contributor
 
Sky Sharkster's Avatar
 
Join Date: Aug 2005
Location: Denver, Colorado
Posts: 5,455
Default Launch Trim?

Hi Mike,
The launch trim consists of two parts, the rudder and elevator. I've been putting them in separately, but I guess you could do them together if you're careful.
The rudder trim is one or (at most) two clicks of right turn for launch, to counter the spiral (diving) turn caused by the spinning launch. The harder I throw, the more it's needed. On a weak toss, it's not needed at all, and can cause a sharp right banking turn.
A small bit of down elevator will help the over-the-top or looping climb. Again, this is worse with a hard toss. The elevator trim is set for a couple of degrees of positive incidence for a good glide at slow speed, but this is too much "Up" at high launch speed. If the nose gets past 90 degrees during the climb, it will 1/2 loop or stall, costing a lot of altitude.
Ideally, it should just be nearing a true vertical attitude as it runs out of airspeed at the top, and you can push the nose over into a straight-ahead glide. Then you pop the "Glide" trim switch and look for lift.
Part of the equation is the exact position of the glider relative to the wind at the release point. I've found that my launches are better if I'm not quite dead into the wind, but slightly before that. It's just coming into the wind, if that makes any sense. It's hard to explain.
Last, you'll catch the model more often if you give up on lift-finding at about 15' altitude and just set up your landing to come around about 5-6' altitude straight into the wind, heading right towards yourself. Get it floating level and at the last second, remove your hand from the TX stick and catch it. I usually grab the wing, it's flying slowly and doesn't seem to hurt anything. I catch about 1/2 the landings this way.
Ron
Sky Sharkster is offline  
 
Page generated in 0.05514 seconds with 8 queries