dynaflite super decathlon
06-02-2007, 08:59 PM
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dynaflite super decathlon
need a little help -------have a dynaflite super decathlon with a G-38 engine and a 18/6 prop turns 9800rpm, plane came in at 18lbs [ my first gas plane ] it dosn'''t want to clime out and need to set it down because of not wanting to turn right --- seams like slow air speed . thanks for any help bob
06-03-2007, 08:21 AM
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RE: dynaflite super decathlon
First of all 18 lbs. is a lot of weight for a G38 to do anything but fly it around.
Secondly try an 18 - 8 or an 18 - 10 prop and you'll probably get more air speed - 9800 on a G38 is a LOT of rpm's, it should run around 7500.
Thirdly large planes like this USUALLY need rudder along with alierons in order to turn with any kind of authority. People usually mix rudder with ailerons right in the transmitter. Maybe adding some more right thrust will help also.
Hope this helps ...........
Secondly try an 18 - 8 or an 18 - 10 prop and you'll probably get more air speed - 9800 on a G38 is a LOT of rpm's, it should run around 7500.
Thirdly large planes like this USUALLY need rudder along with alierons in order to turn with any kind of authority. People usually mix rudder with ailerons right in the transmitter. Maybe adding some more right thrust will help also.
Hope this helps ...........
06-13-2007, 03:44 PM
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RE: dynaflite super decathlon
Definitely drop to an 18x8 prop and see how it does. My Dynaflite Decathlon with a G38 has plenty of power to do far more than just fly around. I haven't had a chance to weigh it but it would not surprise me at all to be over 18 lbs with it (Solartex covering which was then painted, fiberglass cowl/pants, smoke system).
I'm not sure what you mean by it not wanting to turn right. Are your control surfaces deflecting the same distance when giving left and right inputs on the ground?
I'm not sure what you mean by it not wanting to turn right. Are your control surfaces deflecting the same distance when giving left and right inputs on the ground?
06-14-2007, 10:20 PM
#6
RE: dynaflite super decathlon
Hey rthalls,
I also have this big girl and it weighed in at 17.1 lbs with the G38 using the Top Flite 18x8 prop. I have great performance but due to the wing design and wing loading you will need to keep your speeds up both during takeoff and landings. This plane has a very tight threshold between MCA (Minimum Controlable Airspeed) and an outright stall - be careful, keep your landing speeds up. Also, check the incedence of both your main wings and Horizontal Stab. The H-Stab should be zero (0) with no tolerance. Meaning this is very critical for this plane. The instruction explain this in detail but ask if your unsure. Check your wing incedence too. If the H-stab is not zero it will cause your tail to be too sensitive and possibly droopy. My rudder deflection is very little for this plane. Very little input gives a lot of action.
Your plane is on the heavy end of the envelope. Check your CG and make sure your within specs. This too will have a dramatic effect on performance. If you can, try to lighten her up a bit, somewhere, somehow. The G38 should have no problem pulling her around. Make sure your engine is broke in (properly) and is tuned in (sounds like it is from what you have said).
Email me direct if you want.
Happy Fly'n
Mark Foster
JetMech64
[email protected]
I also have this big girl and it weighed in at 17.1 lbs with the G38 using the Top Flite 18x8 prop. I have great performance but due to the wing design and wing loading you will need to keep your speeds up both during takeoff and landings. This plane has a very tight threshold between MCA (Minimum Controlable Airspeed) and an outright stall - be careful, keep your landing speeds up. Also, check the incedence of both your main wings and Horizontal Stab. The H-Stab should be zero (0) with no tolerance. Meaning this is very critical for this plane. The instruction explain this in detail but ask if your unsure. Check your wing incedence too. If the H-stab is not zero it will cause your tail to be too sensitive and possibly droopy. My rudder deflection is very little for this plane. Very little input gives a lot of action.
Your plane is on the heavy end of the envelope. Check your CG and make sure your within specs. This too will have a dramatic effect on performance. If you can, try to lighten her up a bit, somewhere, somehow. The G38 should have no problem pulling her around. Make sure your engine is broke in (properly) and is tuned in (sounds like it is from what you have said).
Email me direct if you want.
Happy Fly'n
Mark Foster
JetMech64
[email protected]
06-15-2007, 06:09 AM
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RE: dynaflite super decathlon
Mark,
Did you and I build different airplanes? Granted, it has been a few years since I built my SD, but the horizontal stab was definitely not at zero incidence. The angle shows on the plans (around 2 deg negative, I think), and it is fairly well established by the fuselage construction. The negative incidence is necessary as the wing incidence is also negative, just not as much.
Great flying airplane!
Bedford
Did you and I build different airplanes? Granted, it has been a few years since I built my SD, but the horizontal stab was definitely not at zero incidence. The angle shows on the plans (around 2 deg negative, I think), and it is fairly well established by the fuselage construction. The negative incidence is necessary as the wing incidence is also negative, just not as much.
Great flying airplane!
Bedford
