VR-1.1 Lutra - My First Design (second now) - Build Log

[Timmy]

That one goes more forward. Yours goes more down. If you draw it forward it'll give you more room for Battery.
[Hangar will reply. ]

yeah but then i have to make the fuse longer and then make the wings longer and my mom dosent like big planes.
But I get what you're getting at.

 

[Timmy]

Like this?
By the way those airfoils at the top are waaaay too big so ignore them

 

[Monte.C]

As long as you have enough room for your battery you're good.

 

[Timmy]

How 'bout this:

Its a bit longer but the wing won't look funky on it anymore

 

[Monte.C]

Seriously, whatever you think you need for the battery. After that you could shape it any way you like.
Somebody might chime in to help. You can also compare this design with the others you've flown, compare the battery placement, try to get an idea where it'll need to be. And it's nice to have some leeway.

 

[Timmy]

Here's the top view. Are the wings too small?

 

[Timmy]

Seriously, whatever you think you need for the battery. After that you could shape it any way you like.
Somebody might chime in to help. You can also compare this design with the others you've flown, compare the battery placement, try to get an idea where it'll need to be. And it's nice to have some leeway.

well I'm gonna fly two 1300mahs 3s in it or a 2200mah 3s. or maybe just one 1300?

 

[Monte.C]

As an airplane, by eye it looks terrific. I have no idea if there's enough wing surface area. If it needs to be bigger you can increase the chord instead of the span.

 

[Monte.C]

Depending on your goals - slow, fast, aerobatic - somebody here will help with wing area & power requirements. You can also look into the Wing Cubic Loading equation. Run the numbers for each of the planes you have, then on this new design for comparison.

 

[Timmy]

I've been playing around with the nose and now I don't know anymore

 

[Timmy]

As an airplane, by eye it looks terrific. I have no idea if there's enough wing surface area. If it needs to be bigger you can increase the chord instead of the span.

I've tried that and it ends up looking weird. I can do it a bit.

 

[Timmy]

slow, fast, aerobatic

I want it like that. More acrobatic and fast but still able to go kinda slow.

 

[Monte.C]

Then build my little Stik!!!!!! Did you SEE those snap rolls?!

 

[Monte.C]

Think about this:
With two planes identical except for the motor placement.
Putting the motor behind the CG forces you to put the battery more forward.

For this diagram:
(In distance and weight)
D-batt x W-batt + D-motor1 x W-motor1 = D-batt x W-batt + D-motor2 x W-motor2
(Where D-motor2 is a negative number)

Algebra is your friend.

 

[Timmy]

With two planes identical except for the motor placement.
Putting the motor behind the CG forces you to put the battery more forward.

I know that.

 

[Timmy]

Ok so my plane has a WLC of 10 assuming it weighs one kg. Thats more than I wanted.
Conclusion: i either have to increase my wing span to 1300mm and chord to 200mm (it was 1200mm before and the chord span was 180mm) or make it lighter. I'm gonna do the first option. That brings me to a WLC of 7.5 AKA a park flyer! thats what i want. (assuming the motor can push the plane and I don't go over 1 Kg in weight.)
Here is a link to my plane on eCalc: https://www.ecalc.ch/cgcalc.php?dee...;14;8;0;0;0;0;10;0;0;0;0;20;0;0;0;0;51;25;10; if ya want to check and see if i did anything stupid.

 

[The Hangar]

Here's the top view. Are the wings too small?
View attachment 178308

It looks really good!

 

[The Hangar]

you mean i should have a pointier nose?

I was just suggesting that you might want to change the shape of the nose. I think the second one in the several options that you posted is my favorite though.

 

[Timmy]

I was just suggesting that you might want to change the shape of the nose. I think the second one in the several options that you posted is my favorite though.

Hmm I chose the fourth. Hey I could make a removable nose and have multiple noses! One that's stubby, one pointy and so on.

 

[The Hangar]

Hmm I chose the fourth. Hey I could make a removable nose and have multiple noses! One that's stubby, one pointy and so on.

Go for what you like the best! You'll have to make two nose skins for the 4th option since you can't easily bend the foam the other way in one continuous piece.