The Flying Box - DEVELOPMENT

[StoneKap]

Hi Guys,
I don't know why... but I've been wanting to make a Flying Box. So I started hacking some foam and slapping some stuff together. I start a lot of projects like this that never get finished. So, I thought it would be nice to ask you guys to help us out. Don't worry I'm not going to ask you to drive to Ohio.

After every episode we release, we get dozens of comments about what we should have done. Or how we could have done something different or better. Well, now you can write those comments below... before we finish the episode. This will allow us to incorporate your input!

Watch this first:

Parts used:
TowerPro Brushless Outrunner TP2409_12D
8x6 Electric Prop
hexTronik 9g Servos
Turnigy Plush ESC 30a

 

[colorex]

The first time I read "Flying Box" I thought more of a helicopter than a plane.

If you make it a heli, or hovering-box, it would instead require much tail-heaviness to hold steady in the air. It would also need trimming to prevent torque roll.

About your current design, I would call it vectored thrust rather than ail/elev. It is also in a way an EDF.
It does look though like you need elevator and rudder instead of elevator and aileron, since you have no problem in controlling pitch, but when you try to turn it goes wild.

Please say what you think.

 

[StoneKap]

Currently I have elevons. I'm thinking the lack of roll is due to the low CG.

 

[colorex]

Currently I have elevons. I'm thinking the lack of roll is due to the low CG.

That's why rudder should work better

 

[woodbear]

colorex; That's exactly my thought as well!

Chad; I would imagine that if the modify it with rudder control you would get some sort of turning, but I'm not sure that it'll be enough to handle those neck-breaking turns...
I think you will have to make rudder out of all three vertical surfaces. But hey, try one at a time and see what happens
Fun video, would love to see more "behind the scenes" footage

-Woodbear-

 

[Luis Evertsz]

I think that colorex is right. This in more like an edf so actually this is vectored thrust but anyways its gonna work. Chad, the flying box is fantastic. Just paint 3 sides of the box in a way that you recognize the X axis and the Y axis

 

[Foskje]

What about two batteries, one at the top, another at the bottom, or one at each side?

You should really cover this thing in christmas gift wrap with gift ribbon and bow ( -or is it maybe a bit too early? )

Good luck!

 

[nart]

It looks very difficult to tell which way is up on it, so possibly integrating fpv into would make it easier to control. The trouble then is it being tail heavy, so it would keep trying to look up rather than horizontal...
I agree with colorex as well, a rudder and aileron setup should be much more effective!
nart

 

[Tom O'Connell]

maybe you could put some streamers on it cos at times it looks like it needs to have some form of stab at the back.
and as for the ailerons....little brushed motors on the elevons for like thrust vectoring. One motor per each

 

[BigDon]

I think you have correctly diagnosed the reason for not getting any roll...all the weight on the bottom is preventing it...but not too sure you want roll as you'll then create problems with keeping track on orientation.

If you're determined you want it to roll then you need to distribute the weight onto all 4 sides, if you just add it top and bottom it will become very unstable and will tend to want to fly on to it's side (think see-saw balancing weight) and if you add just left and right then it will be slow to bank to 90 degrees, but once past that point it will flip to upside down.

We faced similar issues with a Snowman and a Christmas Tree. Go to about 4:35 in the following video. You will see that the Christmas Tree had plenty of roll...but lack of orientation resulted in it being hard to control. With the Snowman, I overcame this by intentionally setting the battery slightly further from the centre so as to provide some resistance to the roll, but left enough so as I could still "bank and yank".

As you need the weight to be so far forward, not sure the option of centralising the weight is realistic unless youe move the motor forward and can set the battery on the cross bracing just behind it.

 

[StoneKap]

If you're determined you want it to roll then you need to distribute the weight onto all 4 sides, if you just add it top and bottom it will become very unstable and will tend to want to fly on to it's side (think see-saw balancing weight) and if you add just left and right then it will be slow to bank to 90 degrees, but once past that point it will flip to upside down.

Really great input... From everyone!
It'll be simple enough to add a rudder (Colorex) so I'll give that a try first. Then we'll go from there. I might also adjust the airframe, making it a cube. I originally wanted a cube, but I thought it would have to be a more streamlined to fly properly. This might help with the CG being so far forward.

I'll keep you guys updated... I love collaborating!

 

[colorex]

I hope it works out for you!

 

[JimCR120]

This thread is interesting to me because for years I also have wanted to make something odd fly, one of those large oatmeal container tubes. I suspect the success yo find here will help me if I ever get around to giving it a try.

 

[Bigshow4u]

i would add some color just for orientation. Next I wonder if a gyro would help any. Only things i can think of at this point.

 

[jetpackninja]

Shak'n it up. Just my two cents- worth every penny.
I'm thinking if you turn the box on the diagonal, think of a box kite and how it flies. and use v-tail mixing with the rear-bottom surfaces of the box being the control surfaces?

 

[Jeffrey Saelee]

You should put a gyro or two on it. And, the rudder.

 

[Tom O'Connell]

get one of those stablility systems that people use on fpv planes. not just a gyro but ones with accelrometers in aswell so it will try its best to keep the box upright

 

[earthsciteach]

Chad,
The obvious problem is that you are trying to make a box fly. Go with a flying rhombus.

You said it-the problem is that the weight is on the bottom. If you can place the battery, esc, etc along the central axis of the box, elevons will work great. Otherwise, as Colorex said, you will need rudder to turn the box. Why not do both? Keep the cg in the same location, but place the battery along the central axis. Add rudder along with elevon mixing. That box will be ridiculous!

 

[colorex]

get one of those stablility systems that people use on fpv planes. not just a gyro but ones with accelrometers in aswell so it will try its best to keep the box upright

That would be going to extremes just for a fun experiment...

There's a term for that... ... OVERKILL!

 

[Tom O'Connell]

there is another way you could get roll and it would make the plane more stable at the same time.
Basically you could get some type of weight on the CG and have it on something to make it move side to side, connected to a servo. After that you would have more weight on the bottom keeping it upright but then when you want to turn it the weight would be shifting making turns easier (in theory)