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=59&product_id=50
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=60&product_id=51
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!
Comments
Ok,. as requested some weight break downs:
Outer Wing Left: 175g
Outer Wing Right: 355g
Inner Wing Left: 355g
Inner Wing Right: 175g
Tail V Mount: 49g
Pod: 595g
V Tail - left: 68g
V Tail - right 68g
Wing Joiners 115g
Boom 50g
Misc/Horns, clevises etc: 150g
Total: 2155g
In addition to this you have the servos; motors, nose weight fpv gear etc. Our test models have shown end weight to come in at around 2800 - 2900g when using a cheap 4000mah 3cell from hobbyking, glider drive etc..
Rob
Sure,
That's one way to see it.
I've been flying a Graphite 2E for 4 years and from day 1 I made a glass hatch that holds the gopro camera in itself. It still holds. Camera weighs about 75 grams and one would think it adds stress to the hatch, which it does but holds as new after 4 years. And I do aerobatics as well.
Just saying..
Cheers,
Mark
Hello
Whew... was not sure if I should be worried or complimented on the comparison!
The pod should not cause any issue. There is a reason the wings have a dedicated pocket on each side to store a vtx and an rx in them! The idea is to move these items way out on the wing away from all the electrics, motors, batteries etc.
For the canopy.. carbon is more durable; preventing it from cracking through the continual flexing that occurs when taking it on and off. An unfortunate balance of requirements. You can almost see the next person saying.. "my canopy keeps breaking - it should be carbon"
That being said; if there is a demand for a glass version (with spares to replace those that break) then they can easily be provided :-)
Hey Rob!
Thanks for a quick answer! I am not about to start comparison of Maxa and many other gliders. Agree, they are different league.
Yes, Maxa has carbon wings and Maxa made for competition and I have to work around it for FPV. Your glider made for FPV. It has a top pod hatch which is un-penetrable for the radio waves and may limit the use of the pod.
Design has to be consistent with the purpose, that's all I am saying.
I hope you'll not take is as personal note, rather trying to help you resolve the future issues and have the highest review rating which in-turn will help you achieve better sales..
Regards,
Mark.
Was curious.. You are worried about 2 small canopies being carbon.. Yet the maxa has carbon wings. (assume I have the same model you are thinking of?)
Overall.. The maxa is in a different league altogether. Much much more expensive.. And for a reason.
You would be better comparing the skyhook to the likes of the epsilom from Staufenbiel. They are built in a similar way.
Build wise.. Let's be honest. This is not rocket science. Foam skinned wings have been around for decades. Not sure the build of them needs much detail beyond that they are foam with spar and balsa skin. They are stiff enough for the function of the aircraft and the flight that is to be expected. They will happily handle the stress of aerobatics. Big dives, reversals etc, outside loops etc. Just like any well built slope soarer :)
It's all a trade off. They could be made lighter and stiffer with a composite skin.. But that increasea cost etc..
Anyway. I am going to way each part for you tonight. That way you have all the answers you need :)
Rob,
Thanks a lot for your reply!
As I stated before, we're interested in empty weights, especially by-part weights. What I personally need it for is to equip it by my specs and figure out the TOW based on my equipment.
It is a best practice for hi-performance RC gliders as pilots do have their own vision on equipment and weight distribution.
It also helps to have sq. footage for each part.
I personally ready to buy Maxa 4 meter glider and build my own fus pod for FPV as this glider is very light and strong but it'll cost around $2K. I know in advance how it is built, what a weights are and how weights distributed.
I can use a cheaper version to work-out most of the FPV and auto-pilot settings for hi-performance glider and in case I missed something the damage will not be as great.
BTW, I can see you have two hatches made of carbon fiber. I'd rather have them fiberglassed as it will make them clear for the radio signals.
Cheers,
Mark
@Michael. For me it is just for fun. I have been flying gliders since I was 10 years old, which is a long time ago! For FPV I have been really disappointed with what is currently avaiable, wings and "flying bricks". However to get this working nicely, it is time to get ArduPilot up to speed now as well !
@Rob
Just to clarify, the wings do have a glass skin, at least on my version ( I would guess 50 g/m^2 glass cloth wetted with epoxy). It looks like they wetted out the glass skin and laid it on the blue foam core, then applied the balsa over the top. It is quite a nice way to do it. If you glue the balsa skin direct to the core then add the glass on top, you have 2 glue joints, so more weight. The only downside is the balsa is easier to dink, but will probably be easier to get a nice repair if needed.
As regards the aileron servo mounts, I preferred the flush plywood servo mounts on the previous prototypes, which didn't protrude out of the wing, unlike the plastic ones. The plastic ones aren't as neat. I think it is still possible to route away the balsa wing skin and find a ply plate with screw holes underneath the skin and then add a flush 1.5 mm ply skin back with servo on, but it is a bit fiddly.
Overall the quality is pretty good and actually there is not much work to do to get flying. The model is currently version 3, so we have already been solving obvious issues we found. The Chinese guys were exemplary in just getting on and making changes. Their production facilities are impressive. They produce stuff incredibly quickly. The downside is that they are working so hard that they never get any time to fly their creations apparently!
Hi Mark
I will be building another one from the ground up in the next week or two - for the purpose of a build log/manual.
I will endeavour to get these details outlined for you at the same time.
A few quick questions answered:
Ailerons/Flap hinges:
These are hinged by a tape / film. Similar to diamond tape. Result is a gap free flexible hinge.
Servo Wells.
These are pre-cut out with a plastic moulded cover to go over the servo. The cover has a cnc plywood mount to hold a 9g servo. You can of course choose to install any servo and forgo the cnc mount.
Weight
This clocks in at around 2.8kg to 2.9kg depending on batteries/motors/servos chosen.
Wings
These are vac bagged foam core - with an top and bottom spar - skinned in balsa and plastic film. There is a good amount of glass re-enforcement where required on joiners servo wells etc. I will need to await some photos from the factory to show you end layup / internal structures.
Fuselage
This is an epoxy/glass/carbon make up - with structural internal ply box to prevent the pylon flexing. The boom is made from rolled carbon.
Tail feathers
These are foam/balsa skinned - symmetrical aerofoil.
Quality wise
Well.. clearly I can be biased as am involved. So for context..
The models are of a quality I would expect if buying from the likes of Staufenbiel - or any other European supplier. We have worked hard to sort out the wrinkles that seem to plague Chinese clones. For its price point; and construction style - it is pretty damn good! Whats is not... well its not a $00 -$1300 fully composite F3F model.
Its a $300 high quality glass fuselage/foam wing with traditional balsa/film covering. This has of course been intentional. The foam/balsa wing impacts the rf signals less than fully composite! - and costs allot less to make meaning that you get a good quality model at a fantastic price :-)
Build log will follow within 2 weeks :-)
Rob
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