Projects Foamie Biplane!

[someguyinsandy]

A look at my next project. I'm going to give it a go anyway!

What do you think?


Steve in Sandy

 

[Tony]

I like it. I also like the Kfm4 on the wing, that thing should be a lot of fun.

 

[Chris O'Hara]

Way cool! I can't wait to see how it turns out! What is the wingspan/ power setup?

 

[breeze400]

looks cool!

 

[someguyinsandy]

Now that I have a general direction, I'm going to work out the engineering stuff tonight and tomorrow night. I'll begin the final build Wednesday morning, and should have it completed by the end of the day. I need a motor - size yet to be determined, and of course an ESC. I have all but one of the servos, so I'll pick it up tomorrow.

Thanks to some great responses to my "Picking the "correct" motor and prop" thread, I now have a decent power calculator! If I can get the drag, and weight figured tonight I don't see any problems with completion on schedule!

Right now I'm thinking a wingspan of about 30", total length somewhere around 20-22", and I'm going to start calculating with a 400 sized motor, and 30 Amp ESC. I estimate final all up weight to be somewhere around 525 grams. We'll see where it goes from there.

Thanks for the interest! This forum rocks!

 

[Tony]

be ready for it, with a fuse that much shorter than the wing it can become pitchy. Can't wait to see how this turns out.

 

[someguyinsandy]

I broke out the razor knife and cut the original mockup down into what I hope will be a more suitable final shape. Currently, the mockup upper wingspan is 24 inches. The lower is 20 inches. Chord for both wings is 5 inches. The aspect ratio now is almost at a 5... I know, it should be more like a 6 but it will be close once it gets scaled up. (I'm keeping the chord the same)

The final plane will end up about 20% larger than the mockup when it is done.

For power I'll use a 370 size brushless outrunner, 20 Amp ESC, and it'll pack a 1.3 Amp Li-Po battery. It will be using Hi-Tech HS-55 servos for the rudder and elevator, and a single HS-65 Metal Gear servo to control the ailerons.

I am hoping to complete this build while off work on the 4th! Maybe even a maiden that evening if I have all the parts I need to get it done.


Steve in Sandy

 

[Tony]

Dude, we need some more members like you. I mean you have a passion for scratch building and I love it! Makes me want to finish what I"m working on lol.

The wing looks much better in this video. Should be a great flier. That reminds me, I need to get the cash up and get a new motor/ESC for my Bipe. I have only flown it a few times and folded the landing gear on a perfect landing once lmao.

 

[Lee]

Looks great. I'm a multiwing fan. My DR1 Red Baron was my favourite scratch build. Now i have a supply of foam board, i think i'll build another one. Can't wait to see the maiden.

 

[someguyinsandy]

Well, I do now...

Here in the near future I plan to pick up a small bulsa kit from the LHS. Foam is one thing, but I want to get to the point where I can build a real model. I have this feeling though that once I get into bulsa, monocoat, and the rest that I'll wish I was building with foam again!

Mmmm, probably not

Steve in Sandy

 

[Tony]

lmao, no you won't. Once you go with a balsa plane and learn how to make them strong, you will never want to return. I still like to scratch build just so I can throw something around and not have to worry about crashing. All of mine are belly landers (the foam ones) and I have never broken a prop. But my balsa planes fly so much better and just stick in the sky where I put them. Love it.

Lee, you need to build that tri again, that was a great little plane. Was that foam board or depron? I remember it was when you were in Cape Town.

 

[Chris O'Hara]

Well, I do now...

Here in the near future I plan to pick up a small bulsa kit from the LHS. Foam is one thing, but I want to get to the point where I can build a real model. I have this feeling though that once I get into bulsa, monocoat, and the rest that I'll wish I was building with foam again!

Mmmm, probably not

Steve in Sandy

If I can build with balsa, you can too! Just wondering, is that a model of something, or more of a stand off scale model? Whatever it is it looks good!

 

[someguyinsandy]

Chris,

It's just a biplane. No particular make or model - I'm going purely for function, I figure the form will follow! Thanks for the kind words.

Steve in Sandy

- - - Updated - - -

I have the parts, so it's on to the build!

 

[Tony]

That bamboo will do great on that plane. In fact any plane, I use it all the time on my foamie builds. Can't wait to see this thing get going.

 

[someguyinsandy]

I actually took a break from this to go down to the field today! Once I got back I started playing with the ailerons. Something about the pushrods being at an angle like I planned kept bugging me so I mocked it up - which started a whole new round of testing! The results are in the video:

 

[Tony]

I can't say that I'm a fan of the ailerons, but I like the fuse!

 

[someguyinsandy]

I didn't go with my original idea because there was a lot of twisting and whatnot at the control horns. I am open to suggestions, noobie that I am! How would you deal with this Tony?

 

[Lee]

If you are going with the one servo option, then you could put the servo sitting upright with two control arms going to the ailerons in a V formation.

 

[someguyinsandy]

Yea, that was my original plan but I found that there were a lot of twisting forces on the control horns. After sleeping on it, I'm going to the LHS today to pick up two more HS-55's. I'm going with what I know will work - one servo per aileron!

I need to play with the "V" configuration a bit more on the bench before I am comfortable putting it on a plane!

 

[someguyinsandy]

Work is proceeding slower than I had hoped. Apparantly I picked up a case of gabungus from somewhere, so I'm not feeling too well! No matter, here is the current progress...