HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Nov 19, 2012, 01:08 PM
Registered User
The Willamette Valley, Oregon
Joined Dec 2008
1,033 Posts
Discussion
Reversal of bank with no roll input

I want to configure one of my RC gliders to replicate something I've observed in my hang gliders. When I have the glider in a banked attitude and give a nose-down pitch up with no roll input, I want to the glider roll through wings-level and on into a bank in the opposite direction. A roll reversal accomplished with no roll input.

Starting with a 4-servo-wing glider (flaps and ailerons can all be positioned independently), how would you configure the glider to respond in this manner to a pitch-only control input? Any ideas?

Steve
aeronaut999 is offline Find More Posts by aeronaut999
Reply With Quote
Sign up now
to remove ads between posts
Old Nov 19, 2012, 04:00 PM
Registered User
ShoeDLG's Avatar
Germany, BW, Stuttgart
Joined Mar 2012
741 Posts
So you want the glider to roll in response to pitch inputs. You mentioned that you have flaps and ailerons. If you want this to work in both directions, then you would have to deflect the ailerons and flaps symmetrically (if at all) in response to a pitch input. This would also rule out rudder deflection in response to a pitch input. This sounds like an objectionable flying quality, not sure why you'd want to reproduce it.
ShoeDLG is offline Find More Posts by ShoeDLG
Reply With Quote
Old Nov 19, 2012, 06:03 PM
I'm #4 on Lindsay's list!
vespa's Avatar
Thousand Oaks, CA
Joined Mar 2004
2,376 Posts
I don't know what a "nose down pitch up" is nor can I imagine the purpose of your goal but it sounds like you are seeking severe Dutch roll. This is pretty easy to design in, simply reduce yaw stability as much as possible while greatly increasing roll stability. Where most aircraft use dihedral for roll stability, hang gliders use sweep and pendulum effects to provide a roll stability that varies widely with AoA and dynamics. With no vertical fin and enormous roll stability the Dutch roll is extremely severe but can be varied in magnitude or even reversed with perfectly timed pitch input.
vespa is offline Find More Posts by vespa
Reply With Quote
Old Nov 19, 2012, 06:56 PM
B for Bruce
BMatthews's Avatar
The 'Wack, BC, Canada
Joined Oct 2002
10,895 Posts
I would say that this is one place where the charactaristics of a wing only hang glider that is controlled by weight shifting is simply not going to be in any way transferrable to a conventional model.

You can't even mix this in, not that it would be a good idea anyway, since the mix has no way of knowing which way the model is banked and therefore which way to roll it.

The only way you'll get a design to do what you want is to make a weight shift controlled hang glider model that faithfully models the one you're used to flying. What you're describing just doesn't happen in any way or form for "normal" tailed designs.
BMatthews is offline Find More Posts by BMatthews
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion puzzle: roll reversal with no roll input in wingovers etc aeronaut999 Modeling Science 25 Aug 08, 2012 12:17 AM
Discussion Can you demo a roll reversal with no roll input in wingovers etc? aeronaut999 Slope 9 Aug 01, 2012 04:13 PM
Discussion Sebart Sbach 30E Banks to Right on Hard Eleavtor Inputs mahbouni 3D Flying 9 Jun 01, 2012 03:57 PM
Discussion Blade MSR X Starts flying forward or backward with no input scohrdarkshado Micro Helis 1 Mar 07, 2012 08:44 PM
Question cp2 drop with yaw and roll inputs Odrapnew Micro Helis 0 Feb 03, 2007 12:03 PM