Balsa or Bass on a rudder? I am building a 4*40 and want a bigger rudder. I have a lot of 1/4 X 5/8 balsa and bass. Should I use bass? I built a balsa rudder and I don't think it would hold up for long.

Thanks!

E:

Use a bass leading edge, frame up the rest with balsa, then skin it with the grain running chordwise.

If the control horn will mount on the bass that's all you need, if the horn mounts further back make the mounting area solid - stick a balsa block inside where the horn will go.

Bill.

That is what I was thinking, but without the sheeting. I don't think I need to go that far with a 4*40. Perhaps another section of bass on the bottom for a little extra strength?

E:

Probably fine without the sheeting, when I scratch I tend to go heavy. Never break one that way. Sometimes they're real lead sleds, but I dont break them.

I've gone too far the other way also, though. Just trashed my first prototype for the Duellist 2/15, almost no internal structure in the afterbody, 43" long, 1/16" balsa skin. Mounted the tail feathers, grabbed the fuse at the wing saddle and shook it, tried to make a fan - checking for resistance to aerodynamic loads. Reached down to pick up the tailfeathers, and got my broom and dustpan to pick up the shattered afterbody.

True story. Haw on me.

Bill.

Wow! I guess it is Maple from now on for me!

I've read many a 4* bash thread and none that made a larger rudder suggested using anything but balsa. Some add up to 1 inch and I've heard no weakness complaints. It's 3/16" sheet and not 1/4". I think your worries may be unfounded.

They probably are fine with the sheet, but I think it is cool to go with sticks! I went with a bass LE and bottom, with a bass brace. The rest is balsa. I will post a pic when done.

The left was all bass, hogged out to save weight.

Next was all balsa.

Next one is bass and balsa, but the top was too wide.

The right one is the keeper. Bass bottom, left LE and LE support that runs 1/3 of the way up the LE. The rest is balsa. Should be strong enough!

"When I scratch I tend to go heavy. Never break one that way."

Airplanes are meant to fly, not be indestructible. Lighter planes are ALWAYS fly better. If it flies better, there's less chance you'll crash.

Roger

rogerflies:

Look at it the other way, too; heavy isn't all bad.

A lead sled won't get flown as often, with less exposure to the possibility of crashing.

That makes the overweight planes last as long as the light ones.

Therefore why build light?

Haw. Tongue in cheek, of course.

Bill.

I suppose I should have added this:

Most planes will eventually arrive at a crash site. With a lighter plane, getting there is a lot more fun.

If you make the tail parts lighter, you can make the fuselage lighter, then the wing, followed by the landing gear. Eventually you find the engine doesn't need to be quite so big. Since the smaller one doesn't shake so much, you can take some reinforcements out of the fuselage, use smaller servos, and a smaller battery...........

Roger

Roger:

Make this lighter, need less strength there, use a smaller engine and save more weight...

It's a vicious circle, isn't it?

Haw.

Bill.

Sure Roger,
Keep at it and you won't HAVE a plane to fly!
Dennis-

I dip mine in molten steel when they are done, just incase I crash
(which come to think of it...is quite often...)