Flight not Climbing

[ctflight999]

Hi,
I am a Division B Scioly flight competitor. I have a flight that consistently flies at 20-30 sec with almost no climbing at all. My flight is the latest Division B model and weighs about 8.3 grams. I use a 0.079" rubber band and wind to 1000. I have a goal of getting over 1 minute. I will post a video of my flight flying later! Please give tips on how to make it climb higher and longer as soon as possible!

[pumptato-cat]

Hey,

Have you read through this page yet? If not, please do--it's very helpful!

https://www.freeflight.org/science-olym ... esources/

Also, when asking for help please provide as much information as possible about your flight so the coaches/other experienced fliers can give more specific/helpful advice(ex. CG, incidence, rubber density, winds, max+launch torque, etc. If you don't know what those mean the document will clear it up!).

[bjt4888]

Hi,
I am a Division B Scioly flight competitor. I have a flight that consistently flies at 20-30 sec with almost no climbing at all. My flight is the latest Division B model and weighs about 8.3 grams. I use a 0.079" rubber band and wind to 1000. I have a goal of getting over 1 minute. I will post a video of my flight flying later! Please give tips on how to make it climb higher and longer as soon as possible!

As Cat recommends, read the NFFS basic trim guide. It's only 3 pages and is mostly pictures. Check your five basic trim parameters (see guide) measurements and compare to your kit recommendations. Then supply as much of the requested info as possible.

Good job getting your airplane flying!

Brian T

Which kit are you using

[ctflight999]

Thanks for the useful tips!
My flight is the latest Division B Freedom Flight Model.
I will check the measurements and post that later/also will trim according to your recommendations and let you know!

[ctflight999]

Thanks again for the trimming tips!
I was not winding enough/ using a rubber with enough torque.
My incidence angle was not generating enough climb.
My flight time is now 1:30 - 1:40, with a climb of 25-30 ft!

[coachchuckaahs]

Excellent progress!

Keep following the basic trimming and rubber winding guidance during your continued efforts. You will find that anytime something is changed, you should go back to the basics. Adjust (increase) your decalage (incidence) until low power flight starts to stall. Then back off a little until stalling stops. With this year's planes the stall may include repeated dipping, or may just be excessively nose-high "mushing" flight. The plane should fly slightly nose high, but not mush.

Once this is set for LOW POWER flight (non-climbing), then start to wind hard (to near breaking, 1.0-1.5 on the max torque) and then back off to launch torque. Work up launch torque slowly, starting around 0.35 until your climb is where you want it. Don't change decalage for climb, it is set for cruise and letdown.

Finally work on matching your rubber width to your prop to use up most of the winds at landing. This should not be done until you are getting to the ceiling or nearly so. If you do not have small changes in rubber width available you can make very small changes to prop pitch, but you do not want to stray a lot on prop pitch or efficiency will go down.

Good luck, keep good records of what works and what does not, and let us know how you are progressing.

Coach Chuck

[jgrischow1]

Excellent progress!

Keep following the basic trimming and rubber winding guidance during your continued efforts. You will find that anytime something is changed, you should go back to the basics. Adjust (increase) your decalage (incidence) until low power flight starts to stall. Then back off a little until stalling stops. With this year's planes the stall may include repeated dipping, or may just be excessively nose-high "mushing" flight. The plane should fly slightly nose high, but not mush.

Once this is set for LOW POWER flight (non-climbing), then start to wind hard (to near breaking, 1.0-1.5 on the max torque) and then back off to launch torque. Work up launch torque slowly, starting around 0.35 until your climb is where you want it. Don't change decalage for climb, it is set for cruise and letdown.

Finally work on matching your rubber width to your prop to use up most of the winds at landing. This should not be done until you are getting to the ceiling or nearly so. If you do not have small changes in rubber width available you can make very small changes to prop pitch, but you do not want to stray a lot on prop pitch or efficiency will go down.

Good luck, keep good records of what works and what does not, and let us know how you are progressing.

Coach Chuck

I'm sure this has been answered before but does max torque/total winds have any effect on max height, or is it strictly launch torque? If I have two flights and they are the exact same except one I wind to 1200 winds/1.5 max torque (let's say) and another I wind to 1400 winds/1.7 max torque, but back down both to .5 launch torque, should they reach the same peak altitude?

[coachchuckaahs]

If you take this to the extreme, compare a wind up to 0.5 torque, vs a wind up to 1.5 and then down to 0.5, you will see a huge difference. This is because hysteresis will kick in and the torque will drop sharply on launch for the one wound UP to launch torque.

If you extrapolate that, the one wound to 1.7 may climb a bit more than the one wound to 1.5, but I don't think it will be huge. If you are winding enough that the unwinds get you onto the dewind torque curve the effect will be secondary. I think you will see a big difference winding to say 0.7-0.8 and unwind to 0.5 vs to 1.5 then down.

Winding harder at the top will likely get you more net winds, which can help with overall duration.

Coach Chuck

[jgrischow1]

Thanks!