Challenge and Some additional fun

L Edge

Master member
Taken from another thread where a student wanted some ideas:

The Challenge is to build a foamie that can fly within the constraints of an indoor basketball court, with a takeoff then a racetrack pattern, flying through a single (upright) 6ft hoop, and then drop a payload (candybar) onto a small (2ft diameter) target, and then re-land in the same takeoff/landing area.
Some constraints are that we cannot use off the shelf products for the airfoils and body, must use the supplied 2 motors and props, and it must be fixed wing.

So, no off shelf products for airfoils, body and it must be a fixed wing. So a second evaluation(bipe, first) has to be like a STOL or VTOL concept.
Hey, I did that years ago(indirectly) with this design where I was looking to land inverted and take off inverted plus wave to the crowd. It was always a show stopper at the flying field. I did my design from a video and later it introduced me to explore and build/flying inclined wings for STOL setups such as the Canada CL-83 airplane. I will build model 2 and show you it's capabilities.

Lost plans over the years, so onto the paper approach with my modifications.

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Since this plane takes a beating, I was given thick depron that no one wanted and it fit the bill.

1) Cut out piece 20(width) x 23(length) which becomes the wing. Using carbon fiber rod, 9 1/2" from leading edge, imbedded rod to prevent bowing. Elevons were designed 3" wide and 9 1/2" leaving gap for rudder. Beveled 45 degree for controls and used packaging tape over and under to hold in place.

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Next 2 side walls were cut out 27" long by 17" high were cut out with a 7" radius and with a 4" end. Front segment has a 2" thickness and cut out . It was hot glued making sure it was 90 degrees to flat wing.


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L Edge

Master member
Next the vertical stabilizer and movable rudder were added by cutting out a slot in front to mount to the wing for strength. Notice the the movable rudder is shorter than the vertical stabilizer to allow for movement while on the ground.

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Since the bottom half is a mirror image of the top(going to be taken off inverted) it is important that the motor/prop be aligned in the X<Y<Z axis and have no bending. So on the leading edge of the wing a slot was made and I glued a flat carbon sheet to reduce movement due to torque of motor.

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Next the motor was mounted on a thin wood sheet then glued to the wing centered and perpendicular so it should act the same flying regular or inverted. Glued depron wedges top and bottom of motor mount to improve rigidity.

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To really distinguish flying inverted, used evenly spaced orange packing tape on bottom.

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While we were flying pattern competitions, you want the judges to really see the plane. The best colors in the air are red, yellow, black and so it is. By the way, the name of this plane is "OTHER UP 2" .

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If you notice the back of the side frames, it is off the ground. The vertical stab is higher so that allows it to taxi around on the ground and the rudder is allowed to move for ground turns. The additional radius allows you to flip the plane over and go the other direction.
Third point, add power and up/down elevator and stop the wing when vertical and wave to the spectators.

Notice that the wing and prop are now 13 degrees slanted upward. We now have the makings of a STOL by breaking the thrust components so you have forward as well as upward.

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Need to re-enforce the sides and install servos/electronics and ready to fly.
 
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FoamyDM

Building Fool-Flying Noob
I have an EZ Powered Walk behind Glider design. Haven't tested it thoroughly, but it has made one circuit.
 

L Edge

Master member
I have an EZ Powered Walk behind Glider design. Haven't tested it thoroughly, but it has made one circuit.

I am very interested in that.
 

L Edge

Master member
Today ended up installing the servos and electronics on OTHER UP 2. As I mentioned before, doing the mirror image has me putting the ESC, servos and Rx all on the bottom.

The battery will be on top so much of the weight will equal the bottom electronics and servos, wire. That way when you take off inverted, the controls should act the same.

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Last part will be to stiffen the side walls to the wing at the radius point top and bottom so it doesn't fold or collapse.
 

L Edge

Master member
Finished off electronics and use 2 mm carbon rod to keep side rails 90 degrees to flat wing.

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Only thing left is to figure out the best prop (using a 10 x 4.7 SF) to start off on the 2 assignments. In bedroom, held it vertical and let go. All good.
Now to home in to see if flying thru hoop is possible and how candy drop will go. Then onto the fun of landing inverted, waving, and taking off inverted.

Videos to follow when winds calm down.
 

L Edge

Master member

Winds were a bother, but did the maiden and learned a lot. Needed full power to start ground movement, about 1/3 power to fly level with 13 degree flat plate. CG needs to be moved forward, small rudder worked well and did right and left turns and to slow it down, pull up elevator and it holds altitude.
Need to go higher and explore vertical control to see if candy drop will go.
 

L Edge

Master member
Congrats. Very interesting project. What motor and prop?

It is an E-Flite 370 1360KV motor that is 3S and covers a range of props from 8 x3.8 to a 10 x 4.7.

Still unsure about the prop yet, haven't dialed in yet. Challenge requires me to fly slow at a high alpha and go into vertical hover where landing inverted and taking off is a different feel.

I found finding the right prop is the ticket that makes the plane tops. Heck, I even feel the difference between a APC 9 x 3.8 SF and a APC 9 x 4/8 where one locks it in better than the other. Also remember as the sizes get larger there are the wide props that will improve especially in hovering.
 

L Edge

Master member
Second day, dew on grass, got a few short runs in with no wind. Changed the CG and definitely is a rudder needed animal to fly. Throttle management is a must where you need to pull back as soon as its into the air. Left and right turns are different so I going to try to incorporate differential aileron mixing.

The mixing is used to reduce unwanted yaw characteristics during roll inputs. You need to have 2 servos to operate the ailerons. Very few pilots even know it exist. Looks like it is can be controllable and hints of going vert as well as slowing down. Be aware that I forgot to cut out segment of blank grass so move video forward.

 

L Edge

Master member
No video today, took 2 runs and it reminds me very much of flying a helicopter that is in transition either from hovering to forward flight or doing the reverse. So I will need practice so I will feel comfortable going between a 6 ft hoop and then go vert to drop the candy on a 2 ft spot. That is Just like autorotation on a 1 meter target.