Idea F 35, Air Hogs gone wild, plans posted

[leadfeather]

Here is my latest project, an F 35 made from EPP. This bird uses WAM thrusters (Wing Aft Motors), Air Hog style. I wanted to try this because I like the control authority the prop in slot type set up provides, but I didn't want to have slots in my wings.

This plane is phase I; conventional flight. Eventually I would like to see if I can do phase II; VTOL.

Here is a short video of the maiden flight. So far so good. The high Apha flying was surprisingly good...no gyros or special controls surfaces.

F 35 Maiden VTOL RC (2 min 55 sec)

[Hughbert]

No more did I start thinking about a twin motor hi-alpha/3D plane than I find you've already built one, and made it a sweet looking jet to boot. Good Job!

Seriously, looking really good - I can't get sound on my laptop atm so if you explain it my apologies but what channels have you set up; elevons and then yaw control on the two motors? have you thought of any kind of pitch control vectoring for the motors as well? You know, just in case it isn't cool enough

How're you thinking of doing the VTOL?

[leadfeather]

Originally Posted by Hughbert

No more did I start thinking about a twin motor hi-alpha/3D plane than I find you've already built one, and made it a sweet looking jet to boot. Good Job!

Seriously, looking really good - I can't get sound on my laptop atm so if you explain it my apologies but what channels have you set up; elevons and then yaw control on the two motors? have you thought of any kind of pitch control vectoring for the motors as well? You know, just in case it isn't cool enough

How're you thinking of doing the VTOL?

hughbert, thanks for the kudos, much appreciated.

So far the controls are:

Tailerons per usual elevon set up
Motor A on power channel
Motor B on rudder channel which is slaved 100% to power channel.

As you move add power, both motors come up equally.

As you move the rudder input, Motor B increase or decreases rpm relative to motor A depending on the direction you move the stick.

Pretty simple set up.Others have done this before me.

And yes, I'm hoping to VTOL.

[Rusty-Gunn]

Leadfeather... this is a very cool prop jet. It wants to chew its own tail off ina loop.
Boxhead has his Berzerko, with a simular set up.

[dz1sfb]

Hey Dan,

Downloading the video now. What is the wingspan? and did you tweak any of the profiles?

Love the paint job.

Ken

[leadfeather]

Originally Posted by dz1sfb

Hey Dan,

Downloading the video now. What is the wingspan? and did you tweak any of the profiles?

Love the paint job.

Ken

Hey Ken, the span is 24". No changes to the 3 view drawings; just built it as drawn.

(edit: will be modifying the drawings a little to avoid some spiral instability)

Rusty, thanks for the kind words. That great control with the prop blast over the tails surfaces allows those really tight loops/flips. It was this same ability in the Kosh/Dekan F-22 and in the FireFly that gave me the idea that this type of control might be harnessed for hovering flight too.

[flying-llama]

Originally Posted by leadfeather

Here is my latest project, an F 35 made from EPP. This bird uses WAM thrusters (Wing Aft Motors), Air Hog style. I wanted to try this because I like the control authority the prop in slot type set up provides, but I didn't want to have slots in my wings.
...

Nice!
The protection and control authority of prop-in-slot without having
to cut a slot.
Also, with the middle fuse uncut, one can scale this down to ~1oz. size
and put a sukhoi or green dot vapor (5 channel) brick (with its built-in servos) in the middle:
no prop to get in the way of the pushrods.

[leadfeather]

Originally Posted by flying-llama

Nice!
The protection and control authority of prop-in-slot without having
to cut a slot.
Also, with the middle fuse uncut, one can scale this down to ~1oz. size
and put a sukhoi or green dot vapor (5 channel) brick (with its built-in servos) in the middle:
no prop to get in the way of the pushrods.

That would be very cool!! Could you get the differential thrust/two motors from that brick?

I flew the F 35 a bit more tonight. One thing I noticed is that if I moved the cg a little too far back it started to get laterally unstable. The wing itself was fine, just the vertical surfaces become unstable. I either need to make the fins a little bigger or cut the fuse down a bit to correct this.

[Trouble Maker]

Dan,
You have done it again! The F-35 looks very stable and looks like the high alpha flight characteristics are better than any of your builds to date. Looking forward to the modifications you have in store for this one.

Mark

[flying-llama]

Originally Posted by leadfeather

That would be very cool!! Could you get the differential thrust/two motors from that brick?...

I think there is only one ESC built into the brick, so you would need to wire in
a 2nd ESC (or wire in 2 ESC's if the built-in ESC behaves differently from the
wired-in ESC).

[flying-llama]

Originally Posted by leadfeather

...

So far the controls are:

Tailerons per usual elevon set up
Motor A on power channel
Motor B on rudder channel which is slaved 100% to power channel.

As you move add power, both motors come up equally.

As you move the rudder input, Motor B increase or decreases rpm relative to motor A depending on the direction you move the stick.
...

One question/comment: if you fly a low or high throttle, it seems that you may have problems turning in certain directions
(rudder + power to motor B goes below 0% or above 100%).

If you have a spare mix on the Tx, you could mix in rudder at -100%
to motor A.
Then at low throttle, rudder will always increase the power to one motor (even if it reduces power to 0 on the other), and
at high throttle, rudder will always decrease the power to one motor
(even if it uselessly increases power to past 100% on the other).

But for medium power settings and not too much rudder (in either direction),
there probably will not be any problems.

[flying-llama]

Originally Posted by flying-llama

I think there is only one ESC built into the brick, so you would need to wire in
a 2nd ESC (or wire in 2 ESC's if the built-in ESC behaves differently from the
wired-in ESC).

Only 1 ESC built into the Vapor and Sukhoi bricks, but there are 2 ESC's
in the E-flite MCX brick (and with power/rudder mixing).
But there is also a gyro for rudder on that brick, so unless the gyro is disabled,
or the brick is properly oriented, the gyro may cause some strangeness
to the controls.

[MartinT]

Oh Verrrrrry Nice ! ! ! ! !

Are you planning to release this awesome flying machine as a pdf plan?
If so (hopefully!): Looks like I have a new project coming up!

What kind of motor/prop combo did you use?

Best regards,
Martin

[leadfeather]

Originally Posted by flying-llama

One question/comment: if you fly a low or high throttle, it seems that you may have problems turning in certain directions
(rudder + power to motor B goes below 0% or above 100%).

If you have a spare mix on the Tx, you could mix in rudder at -100%
to motor A.
Then at low throttle, rudder will always increase the power to one motor (even if it reduces power to 0 on the other), and
at high throttle, rudder will always decrease the power to one motor
(even if it uselessly increases power to past 100% on the other).

But for medium power settings and not too much rudder (in either direction),
there probably will not be any problems.

That is a good idea. I was trying to think of something like this but your solution is perfect!

So far the simple motor set up is OK but I will probably take your suggestions since I have an open channel.

Thanks for sharing!

[leadfeather]

Originally Posted by flying-llama

Only 1 ESC built into the Vapor and Sukhoi bricks, but there are 2 ESC's
in the E-flite MCX brick (and with power/rudder mixing).
But there is also a gyro for rudder on that brick, so unless the gyro is disabled,
or the brick is properly oriented, the gyro may cause some strangeness
to the controls.

This could be very cool.

I have an MCX I rarely fly, hmmmmmm.