Vega's 2005 contest entry
 

Hi,
Nothing like a deadline to inspire progress :) I managed to assemble the wing panels for my comp entry last night, inspiration came from an article in the current Aeromodeller about all sheet wings.
I have decided that my model will be r/c using rudder, elevator and throttle control. But, a question for any stability pundits out there, how much dihedral to use on a two channel, low wing job without ailerons?
Ta
Jon

RE: Vega's 2005 contest entry
 

Looks like you've got more than one angle going on there. What is their relationship to the dihedral angle?

RE: Vega's 2005 contest entry
 

Hi Ptulmer,

I think the term I was after was polyhedral rather than dihederal!

I read somewhere that there were a few rules of thumb regarding dihedral.

After posting my question I found one reference that the minimum dihedral angle (angle 1 in my pic) for a low winger with v-dihedral without ailerons was 7 degrees, so on my model, about 2 inches under each tip if it had v-dihederal. So angle 2 would be approx 10 degrees for my wing.

Work really detracts from clear aeromodelling thoughts :)

RE: Vega's 2005 contest entry
 

Looks to me like you answered your own question.[sm=lol.gif] You ever heard of TLAR? Make a dry assembly run and make sure That it Looks About Right.

RE: Vega's 2005 contest entry
 

thinking aloud helps me :D

A dry assembly run confirms what an ugly beast I am creating...

RE: Vega's 2005 contest entry
 

I wish I had comforting words for you.... well, maybe it'll be a great flier![&:]

Actually, I'm pretty darn sure it'll be a GREAT flier. Nice planform and a profile fuse, it should scoot around weightlessly!

RE: Vega's 2005 contest entry
 

That's not ugly....I like it!:D One of my 1st successful FF planes way back when was a sheet balsa profile P-51 with a Pee Wee .020 built from a M.A.N. plan.

With all that canopy and V/stab area up high, my TLAR alarm is going off. Methinks you might need more dihedral. With rudder control, too much is way more fun in the air than not enough.

Can you post a front view?

RE: Vega's 2005 contest entry
 

Ptulmer, well fingers crossed that it’ll aviate… as it’s very semi scale, I broadened the wing tip to avoid tip stalls, and there is a good bit of wash out built in too.

Dickeybird, the first pic really flattened out the proposed dihedral, the pic below is what I was thinking of using, 2.5 inches under each tip. The root ribs of each panel are thick so I can sand in the required angles. I’ll add an undercarriage too, just 14g wire wound over the fuselage with a couple of team race wheels. It was older FF plans that really inspired this effort, the various ebineezers and even Eric Cluttons Flying Fish (now that’d make a challenging r/c projectile) :)

Anyway, thanks for your comments! Looking forward to more TLAR vibes on the dihedral.

RE: Vega's 2005 contest entry
 

Ahh, now then....TLAR! Should be fine.:)

RE: Vega's 2005 contest entry
 

Spent a few hours thinking about how to mount the radio on a profile model without letting castor oil run rampant in the electrical gubbins.

My solution has been to cheat and build a pod around the radio (mostly soft 1/4 sheet) and to sort out the wing mount at the same time. There is a hatch to go over the radio space and then some tape to seal. Weight of the beast prior to tissue covering is about 9 ounces with a thumping great 300 mah rx battery.

Still looking good for that first flight in the wind and rain on the 30th of April :D

RE: Vega's 2005 contest entry
 

You've got the gear tucked away real nice! I'll bet you end up with a great performing plane on the 30th!

RE: Vega's 2005 contest entry
 

No such thing -- what you have is a semi-scale A-1E Skyraider.... or minor variation thereof.