Home built DIY Electric Balsa Bi Plane

[flybywire]

[sonyalpha]

It is a beauty. I like the strong colours. It will be easily seen in the air.

Where will it be flown?

[flybywire]

I will try PFW this Fri morning but I think the dihedral is too little to roll the aircraft. Let's see how. Another pilot built this with dihedral a little too much hence I half the angle.

[csisfun]

Nice!!! Seems like you made a few modifications such as a boxy fuse and a solid tail surface.

[Sunstorm]

What's this plane, by the way? I don't remember seeing the plan before...

[flybywire]

Nice!!! Seems like you made a few modifications such as a boxy fuse and a solid tail surface.

I hope the 5 degree dihedral can roll as opposed to yours at 10 degree which is too much. Also the wings are bolt held in place but can be removed as and when its needed using 1.5mm hex, its made more to hold the wings always in the same plane and parallel to each other. The tail was made as in the plan but I find it too flimsy hence the solid surface. Also the rear wheel is steerable so I may try ROG. Front cover is removable by sliding out to change battery easily, I will be using 3s for this aircraft.

[flybywire]

What's this plane, by the way? I don't remember seeing the plan before...

Its a plan not found in the internet that is why you can't remember seeing it.

[joe yap]

These are the pictures of the original. I'll say 5 degrees on each wing is not too much. You can always use lesser throws. If you use too little dihedral, the rudder will be only enough to yaw the plane.

[flybywire]

Do you think the plane will be able to roll?

[joe yap]

It's possible if you have enough dihedral. I've done that several times with my Buttercup.

I read an article in model airplane news magazine many years ago. It mentions that for a model to have yaw induced roll ( we are not talking about 360 degrees roll here), it needs to have at least 3 degrees of 'effective dihedral'.

Effective dihedral takes considerations of wing position, wing sweep and actual dihedral, instead of just actual dihedral angle alone.

An average high wing model already has 1 degrees of positive dihedral even with a flat wing. An average low wing mdoel has 1 degrees of negative dihedral. So, for the high wing plane to turn with rudder, you'll need 3-1=2 degrees, and low wing is 3+1=4 degrees minimum.

For models with very deep fuselage or wings mounted very high up like parasol wing configurations; ie very low CG, they have so much positive effective dihedral that even with flat wings, the rudder is enough to roll the model.

Sweep angle also makes a difference. For every degree of sweep back, you'll get a half a degree of effective dihedral. Forward sweep will have effective anhedral on the other hand. I ever designed and build a model with flat wing but have swept back wings with about 10 degrees. It didn't have ailerons and I could fly it normally with elevator and rudder alone.

For you case, the lower wings may have insufficient dihedral, but the upper wings may have just enough. Since the wings are done, try other means by shifting the CG as low as possible. Place all your servos and battery pack at the bottom of the fuselage and use heavy wheels. In the worst case scenario, change the wingtips to something with some polyhedral.

[jumat]

home made

day 1 dwg,cut n fix a long long way to go
this is my 1st home made plane park flyer la try small frist ...........

ps : i got help from a cnc cutter la but dwg myself ......