Double Ender - STOL Redefined PROTOTYPE

Double Ender - STOL Redefined PROTOTYPE 1.0

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Taildragger

Legendary member
Taildragger submitted a new resource:

Double Ender - STOL Redefined PROTOTYPE - Push-pull Bush plane powered by two 1806 motors

Basic plan for now... more to add later

Thanks to @SP0NZ for the plan format

currently page 1 is a little bigger than 1 sheet of foamboard

For the landing gear, watch the FT simple cub build video

For the wheels, watch the FT bushwacker build video

For anything else, PM me.

Specs:
40in wingspan
2 x 1806 motors
5in 3 blade prop
4 * 9g servos

Read more about this resource...
 

Mr NCT

Site Moderator
I'm waiting on some props and bullet connectors. I've made some minor changes for ease of access and building - I'm lazy. I did a glide test with no electronics and the CG on the plans is dead on. Got a good smooth glide without porpoising. Here's some pics-

IMG_4060.JPG IMG_4061.JPG IMG_4065.JPG IMG_4066.JPG IMG_4071.JPG IMG_4072.JPG IMG_4073.JPG IMG_4074.JPG IMG_4075.JPG IMG_4076.JPG IMG_4077.JPG IMG_4078.JPG
 

Mr NCT

Site Moderator
All set up it took 3/4 oz. in the nose with an 850 3s battery for balance. AUW 426g. The first test flight nosed into the ground, broke the tail boom where it meets the fuselage. Did the repairs and gave the front motor 7° up from the plans. It makes the front edge of the motor pod square with the top. I did a new glide test and confirmed the CG placement with all the electronics but no gear. I launched at low rates and about half throttle. It flies! You'll either have to mix in some rudder or fly with both thumbs.


I'm I the first? Do I win a prize?!?
 

Taildragger

Legendary member
All set up it took 3/4 oz. in the nose with an 850 3s battery for balance. AUW 426g. The first test flight nosed into the ground, broke the tail boom where it meets the fuselage. Did the repairs and gave the front motor 7° up from the plans. It makes the front edge of the motor pod square with the top. I did a new glide test and confirmed the CG placement with all the electronics but no gear. I launched at low rates and about half throttle. It flies! You'll either have to mix in some rudder or fly with both thumbs.

So the thrust likes to pull it down then? How does it feel with the extra angle? Is it decently stable?
And yes you are the first. 🏆
 

Mr NCT

Site Moderator
So the thrust likes to pull it down then? How does it feel with the extra angle? Is it decently stable?
And yes you are the first. 🏆
With the front motor per the plans it nosed right in. I watched the real plane video again and it looks like the front motor on the plane is in line with the top of the motor pod so I tried it. Took off nice and straight. Only flew a couple of minutes, didn't try stalls, throttle setting or anything just made sure I could control it.
 

quorneng

Master member
Depron rather than foam board but my own design "double ender" works very well and with huge double section flaps.
05Aug19.JPG

FlapDownR.JPG

The flaps are controlled by a Tx knob so are infinitely variable 0 to 85 degrees. Provided the speed is allowed to decay gradually as the flaps are lowered the pitch change is quite controllable. The flaps are not stressed for inverted flight!
AET control. Normally flown hand launch/belly land but a simple U/C shows its STOL capability.
Emax 2805 2840 kV motors. 5x3 three blade CW & CCW props. 2200 mAh 2s LiPo in the nose. Aileron and elevator servos 3.7g, flaps 5g.
 

Taildragger

Legendary member
Depron rather than foam board but my own design "double ender" works very well and with huge double section flaps.
View attachment 230642
View attachment 230643
The flaps are controlled by a Tx knob so are infinitely variable 0 to 85 degrees. Provided the speed is allowed to decay gradually as the flaps are lowered the pitch change is quite controllable. The flaps are not stressed for inverted flight!
AET control. Normally flown hand launch/belly land but a simple U/C shows its STOL capability.
Emax 2805 2840 kV motors. 5x3 three blade CW & CCW props. 2200 mAh 2s LiPo in the nose. Aileron and elevator servos 3.7g, flaps 5g.
How on earth did you make double slotted flaps ?
 

quorneng

Master member
Taildragger
Not slotted flaps just two sections bottom tape hinged.
This means when retracted they give a good wing section. Not so much when down but at over 45 degrees it is the underside of the flap that is creating most of the lift by simple air deflection. At full flap it needs quite a bit of power to maintain altitude. ;)
Both flap sections are driven from a single servo arm.
Took a bit of trial and error to set up and even more to ensure the flaps moved more or less identically on both sides!
 

Mr NCT

Site Moderator
Double Ender Airworthiness Directive:
If you haven't built the wing yet (or even if you have) be sure to add something to strengthen the dihedral joints. I flew mine this morning and fortunately saw the 20° - 30° deflection before it failed.
 

L Edge

Master member
Taildragger:

After trying my device on the Firebird(straight wing, it works), I am now going to design a STOL to see how it compares to yours.
Going all out for broke to see what happens, I chose the world's record (DR Chinook)as my plane to duplicate and see if I get it to fly.

So look for my thread and I will explain as I go. Will see what happens.