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Build options

Old 01-08-2021, 11:10 PM
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Default Build options

G'day all
N00b alert and first post.
I've just restarted building gliders after over a decade away. Before launching back into some serious ($'s + performance) models, I've got a couple of simpler/cheaper versions to get my skills back up to scratch.
I'm about to embark on a BangGood Sunbird 2.0 (looks remarkably like the former Hobbyking Sunbird).
It has a few build options: rudder, elevator, ailerons and motor. The plans are for a single 'straight' wing, no dihederal. Now the questions...
I'm thinking to build it with all the options (incl the aileron servos in the wing) and just start initially fly it as RET. Assuming there's nothing I'm missing in that besides the obvious weight disadvantage?
I'd like to build some dihederal into the wing tip joint. Maybe 10 degrees or so. I've done it on smaller wings (although that was in the 'stock' plans). I'd make up the correct angled 'splints'. Also angle the appropriate ribs. Maybe using a jig against rib while the glue sets.
Thoughts, comments, criticisms appreciated.
Old 01-09-2021, 10:48 PM
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First off Welcome back to building and flying and Welcome to RCU.

If you want to fly RET at first then you NEED dihedral. The way the model rolls into and out of the turns when flying with rudder and elevator is the rudder yaws the model and that causes the wing panels with the dihedral to shift their angles of attack to the air quite strongly. And it's that shift which rolls the model into and out of the turns.

You say you want to use ailerons and still angle up the tips. That's fine, the 10 you're thinking of using for the outer panels is actually quite a lot and that amount should respond to yaw from the rudder in a nice positive manner. It may not be ideal but you'll get a reasonable response.

If you fly in calmer to moderate conditions you might also find that you're fine with just committing fully to a proper amount of dihedral and go with RET controls for this first "re-entry" model. And then build a flat(ter) wing model or new flatter aileron model for the fuselage you have already later on. I'd suggest the whole new model because then you can pick something that suits your rapidly returning abilities. Flying these things is much like riding a bicycle. You might be away for a long time and there's no doubt you get rusty... really rusty even. But the past experience comes back quickly and the rust falls off easily. I know that part all too well since I took a bunch of years away for other interests... including the track riding and racing which is obvious from my avatar. I still feel rusty compared to the "old days" but I don't fly as often as I should to get the old skills back. But it does come back fast if you fly often enough.

If you're a builder sort of modeler then for sure go with a nice basic polyhedral model this time and commit to the RET without ailerons. And that way you have an excuse to build a sleeker and more capable flat wing aileron model for the second build.
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WulfKeeper (01-10-2021)
Old 01-10-2021, 04:49 PM
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Thanks for the feedback and suggestions. Makes a lot of sense. Also gels nicely with a lot of reading and feedback from elsewhere. Much appreaciated

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