bjmjs

I lost my dihedral brace & don't have the plans. What do I do?

AJRCUSTOMCRAFTEDRC

My Feedback: (70)

if your a flier above beginner and and able to fly all four channels then i would recommend
no Dihedral ,build it a stright wing . the plane is stable as is but with no Dihedral this will allow you more roll control and the op to fly more acro manuvers. the main thing with the wing is to make sure you have NO TWIST in it .i have built more replacement wing for others and if you over power the plane or plan to do high G's put shear web's on both sides of spar. the 4* is a great plane but has a few bugs in it . i have many in dif forms of this plane and the mid star.
anthony@customcraftedrc P.S if you need some i can make you some or i can send you via email the part you can print out and cut your own.

arkansas flyer

My Feedback: (4)

would like to remove dihedral from four star 40, any comments on this? want more aerobatic capability. and I'm using an evolution 60nx with tuned pipe. Thanks for any suggestions.

KitBuilder

Striaight wing still needs a brace.. just make it yourself... make 2 , one for front and one for back and sandwich the spars in the middle. I forget how far they go out on the 40 size.. first or second rib?? I will still put a smidgen... just looks nice visually..

foodstick

This may be an old wives tale, or not ! I have always heard put in at least a little dihedral, because a wing with NO dihedral always looks like it has anhedral ..hope I got that word right..in other words the wing will look to sag down..

HighPlains

My Feedback: (1)

Since the Four Star is a low wing design, you need some dihedral for it to fly right. If you build it with no dihedral then you will get adverse roll with rudder input. In other words, right rudder will make it roll to the left. I would expect "proverse roll" with the stock dihedral which means that left rudder would cause a slight roll to the left.

So, somewhere between the stock dihedral and a flat wing you can get the airplane to a neutral point where rudder input causes no roll in either direction. Where is this point? Difficult to say, many pattern designs have been modified during their development to find this point. For a one off sport design, just cut down the dihedral by a 1/3 to half and you will be close. If you miss it, you can easily modify the wingtips to fine trim the dihedral effect.

arkansas flyer

My Feedback: (4)

I 'm going to use the brace, just modify the angle so the wing has no dihedral. And clip the wing back one bay each side. I want more roll affect and less drag. I'm using an Evolution 60nx with a tuned pipe and 11x7 APC prop. I had just built one according to plans and crashed at a high rate of speed because of elevator failure. We were clocking it on radar 87mph at 1/3 throttle. I was full throttle into the wind when the sullivan semi flex elevator rod gave up to flutter.Total destruction! This time I'm using sullivan steel control rods, Spektrum A6020 metal gear high torque servos, steel control horns and heavy duty servo arms. extra higes on control surfaces. I want it to stay together this time. Any comments from anyone on building it strong enough to withstand high speed ?

FlyingGreg

My Feedback: (4)

Arkansas,

Man there are many planes out there built for speed. The Sig 4* at any size ain't one of 'em. Course it's your plane and your engine so you can do whatever pleases, but why not get something like a Little Tony, Shoestring, Cosmic Wind or a Patriot if speed is what turns your crank?

arkansas flyer

My Feedback: (4)

Just want to do something different. I the accomplishment of building something different. I have had several of these in the past with different mods. It's easy to fly and land and will burn the sky when needed. The guy at the local hobby shop said they were building them as pylon racers. Who would guess.

Gray Beard

My Feedback: (-1)

We had a trainer class for our club racing, you can use any plane you like in a class. I don't have the plans for the 4* but as i recall the dihedral brace was part of the wing structure. It wasn't a lot of dihedral to begin with. The braces were just 1/8 ply in the center section on the main spars front and rear and one on the LE and TE to hold the wing center section together. Do a search on a couple of the build threads and see how they installed.