Timeline for What are the handling effects of converting a dihedral wing to polyhedral?
Current License: CC BY-SA 4.0
11 events
| when toggle format | what | by | license | comment | |
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| Dec 11, 2019 at 12:12 | comment | added | Zeiss Ikon | @JohnP Dihedral, and especially poly or tip dihedral, is sometimes called "nature's ailerons". A little yaw is just like a lot of aileron input. At very high speed, one twitch on the rudder (usually mapped to the right stick for rudder-elevator models without actual ailerons) and the roll forces generated may break the wing spar. | |
| Dec 11, 2019 at 0:55 | comment | added | JohnP | @RobertDiGiovanni - That's the plan, actually. Start with a "dart" type throw and see how the flight works. Then gradually work up to higher throws (discus launch) and work on just circling back to me, getting used to the RC aspect. Once that is decent, then work on low power launches. I'm also meeting with a local RC club at their next gathering to ask n00blet questions.:) | |
| Dec 10, 2019 at 23:47 | comment | added | Robert DiGiovanni | @JohnP you may have to trim a little elevator down (tail upforce) for the rocket boost to keep it from looping. See how it glides first, then start with the smallest rocket motor (Estes 1/4A3), or a good hard throw from a hill. After boost, reset to glide trim. You may find relevant info in "discus throw launch style" gliders. You may find it flies great without modifications. Good luck! | |
| Dec 10, 2019 at 21:38 | comment | added | JohnP | @ZeissIkon for most rocket boost, there is not really any adjustment during the (1-3 secondish) boost phase. And all control is usually in the tail section, there aren't too many rocket boost gliders that have ailerons in the wing. But I see what you are saying. | |
| Dec 10, 2019 at 21:36 | comment | added | JohnP | @RobertDiGiovanni the tips would remain at the same height. | |
| Dec 10, 2019 at 21:07 | comment | added | Robert DiGiovanni | Raising the wing tips higher may drastically affect the frontal center of drag, by raising it above the center of gravity. Especially for a rocket aircraft this could be absolutely disasterous. Look at the X-15. You want symmetry and plenty of stability. | |
| Dec 10, 2019 at 19:16 | comment | added | Zeiss Ikon | Depends. Poly and tip dihedral are used on trainers -- but with small rudders and low flight speed (because poly recovers to level very positively). A twitch at rocket boost speed, and you're likely to rip the wings off. | |
| Dec 10, 2019 at 19:16 | comment | added | JohnP | so... net effect for a new flyer who will likelier have a heavy touch on the controls would be a "twitchier" handling model with a poly vs di. | |
| Dec 10, 2019 at 18:42 | comment | added | Zeiss Ikon | @JohnP almost correct. A poly wing will produce more roll than simple dihedral, other factors equal. Higher bank, coupled with some elevator input, can produce sharper turns, but the more usual use case is to give usable levels of bank from a smaller rudder or less deflection. | |
| Dec 10, 2019 at 17:45 | comment | added | JohnP | Yaw is movement around the vertical axis, so if I translate correctly, a poly wing will produce sharper turns and greater roll? So a simple dihedral wing is a "genter" handling characteristic? | |
| Dec 10, 2019 at 16:48 | history | answered | Zeiss Ikon | CC BY-SA 4.0 |