A high performance FPV soarer, the SkyHook Discovery

The SkyHook Discovery.

Disclaimer: I was lucky enough to have been given one of the first prototypes as I helped in the design of the plane.

More info from :

http://www.skyhookrc.com/index.php?route=product/product&path=5...

There is also a pure glider version, which uses the same feathers, just a different fuselage pod

http://www.skyhookrc.com/index.php?route=product/product&path=6...

The Skyhook Discovery has been specifically designed for efficient soaring, whilst also being a good stable FPV platform.


The wingspan is 2.5 meters, but the model will break down to fit in a small box. The wing dismantles into 4 pieces, the fuselage boom separates easily from the fuselage pod and the V tail halves are easy to disassemble as well.

The plane has an MH32 wing section which includes a full length 20% chord flap. The MH32 is well known as a slippery airfoil, and the model is capable of flying very fast or very slowly depending on how you set the camber control in flight.

The wing and tail construction is foam with a glass skin sheeted over with balsa. This makes it very rigid. The surface finish is far superior aerodynamically to anything you can achieve with a foamie.

The ailerons are split with the wing panels and are hinged top side on the outer panel and bottom on the inner so you can set up an efficient "crow" flap mode too.

There is a good amount of space for gear in the "pod" between the wings and in the lower fuselage, and there are also pockets in the wings for yet more gear.

I chose a Turnigy GliderDrive 1120kV for mine and a 12 x 6 prop and an 80A Turnigy Plush ESC, and with a 3S 4000 Lipo, it get away nicely. The plane is very stable and rock solid as a camera platform , but also can do aerobatics.

So far I haven't had much time to try it beyond a couple of flights , but I'm looking forward to having some fun with this!

Views: 2227


Developer
Comment by Andrew Tridgell on October 18, 2016 at 1:50pm

That looks like a really nice plane, thanks for sharing!

Comment by Stephen Gloor on October 18, 2016 at 6:23pm

Sighhhh  - my bank account was just building up after the Challenge was over.......

This is exactly what I want as I would like to get back into soaring and have had thoughts about a FPV GPS triangle contest for a while.

Comment by Rob Thomson on October 19, 2016 at 12:21am
Stephen.. You would love it!

The model was originally convinced as my idea.. Then came together after multiple rounds of design work bouncing between myself, Andy and and Byron.

Fortunately byron travels to China almost weekly.. So we where able to ensure that the manufacturers resolved every issue. This means that the model is designed with sound aerodynamic principles - and flies well!

I personally am tired of all the fpv models out there being foam bricks that don't stand a chance of flying at the same level as my non fpv models. As such.. We designed first as a soarer / slope model.. Then worked out how to get the fpv gear in efficiently.

I think we have achieved the design goals. I can't wait for summer so I can get some good sunny thermal conditions!
Comment by Stephen Gloor on October 19, 2016 at 12:39am

Excellent - pretty good price as well.

I am sick of looking at all the puffy cumulus clouds here in Perth and having nothing to do anything about it :-)


Developer
Comment by Andy Little on October 19, 2016 at 1:18am

There is one issue outstanding for me. In order to use well ArduPlane with this model and exploit its capabilities such as camber control and crow flaps, (which will need fin trimming of elevator etc), ArduPlane will need much better and more versatile mixing capabilities than it currently has. I have heard that there is something in the works using the OpenTX mixing scheme, which is good news, though personally, having used the OpenTX GUI mixing, I am not a great fan. It takes a lot of work to  get things working and somethings aren't intuitive, for example evaluation order.

Anyway until something else appears I hope to proceed with my own mixer as outlined here.

https://github.com/kwikius/mixer_lang

and here

http://discuss.ardupilot.org/t/a-new-approach-to-arduplane-mixer-sc...

bearing in mind Andrew Tridgell's comments in the second link

The glider.mix script is based around this plane in fact

https://github.com/kwikius/mixer_lang/blob/master/glider.mix

Comment by Rob Thomson on October 19, 2016 at 1:25am

True.. but it is not the end of the world. Key is to use a flight controller that can mix rudder & aileron. 

On mine I am using MFD AP.

The solution is surprisingly simple.  You only drive a single aileron. And mix this to rudder.

You then handle all mixing on the radio as per normal; and rely on the autopilot to get you home on a single aileron.   Surprisingly.. many full size aircraft work exactly this way!

The ultimate of course is Andy's mixer solution :-)

Comment by Pascal P. on October 19, 2016 at 1:35am

Having a stable and very slow speed capable platform (with such a nice look in addition !) is always very tempting for mapping. Do you think it can fit for that purpose ?

The overall shape make me think of a Delair, which is a very efficient mapper.

Comment by Rob Thomson on October 19, 2016 at 1:44am

Yes.   If you pop camber on - it slows right up.  The question is - what type of hardware do you want to put in the bottom pod.  How big is it etc?

We are considering another fuselage pod option for this purpose - would you need the ability for the fuselage to have a downward facing camera?

Some specifications of this would be useful for this as it is not my area of expertise.  But all up entirely feasible to have an alternative pod with a downward facing camera bay.  Just a question of demand!

Rob


Developer
Comment by Andy Little on October 19, 2016 at 1:45am

@Rob,

It will work fine on papaer , There is a flaw with this simplified approach as outlined here.

http://discuss.ardupilot.org/t/looks-like-ap3-5-guided-mode-crashed...

I believe the problem there was that the plane was put in crow mode as stated in para 4.

Basically your FC needs to know if you are in crow mode, whether you have flaps on etc or not and if necessary switch to another mode to be able to control the plane properly. If you use " pass-through" servos, the flight controller cant be effective i those "panic" moments, which are the very moments when you want to flick the RTL switch

Comment by Rob Thomson on October 19, 2016 at 2:01am
Hmm.. Fair point.

I guess what's key is the failsafe to always put in neutral aileron.

This is fine for my needs.

Best is a decent and flexible mixer in apm. Once that arrives.. Happy days :)

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