Discus launch Gliders

Has anyone on here had a go with these?
I've decided to waste a bit of money, and risk getting a bad back, by building one of these.
Watching the experts, they hold the model by a wing-tip, twirl around once in a circle, and hurl the model up into the sky - to typically 100 feet!
I've ended up with a Libelle, from Dream-Flight, as I didn't fancy spending £500 or so on a few bits of carbon fibre, to find I don't like the idea after all (or I can't chuck them without falling over!)
It is basically a three channel moulded foamy ceiling tile, with a bit of polycarb for the nose pod, and a few bits of carbon rod for strength, with a 46"span.

The fun starts trying to find servos that are tiny enough! Of course, the intended ones are discontinued!
I found a Graupner C261 in my 'spare' servos box, and a Graupner c1081 that is only a couple of mm fatter, but the same l and h, and a couple of Turnigy 555 slim wing servos - to go with the Taranis (frsky) X4R rx - and 2S 450 lipo.
I've got it all 'bound' together and working - with one exception I'll come to in a little while.
Now the 'fun' starts.
Of course -  the moulded recesses in the slightly rubbery foam aren't big enough for ANY of said items, so the modelling knife had to be weilded
Having hacked away the foam for the battery and servos, I find that they sit too tall, so I have to excavate the holes deeper - right down to the polycarb 'tough' skin! That means I have to make a pair of rails for them to screw to. UHU POR holds the rails in. For now, the battery is held in by friction and gravity!
The elevator and rudder are worked by carbon rods with a fitted z-bend at one end -  that run down the inside of the carbon tailboom - and the tailplane 'saddle' is pre-fitted, (to avoid sticking it on cock-eyed!) The rudder rod is longer than the ele one, which emerges through the back of the saddle, not the end of the tail boom. The rudder one is easy, it's a straight run. BUT How the heck can I get a rod to go round a corner to emerge from the 'saddle' with the z-bend in the pod, for the servo connection? The rod slides in easily from the back, but that leaves the z-bend outside, and if I use a linkage connector, that then is too tall, and the canopy won't fit. If I install it upside down, I can't access the locking screw for the rod!
I may end up making a new rod from fine piano wire, threading it through from the back, and then putting a z-bend on the front end, if I can't fiddle it through - z-bend first.

That leads me to the problem I mentioned earlier, re the radio.
The reciever claims to be 4 channel, and it is - IF you use the bus-bar system, which requires different (and expensive) servos - so it is really a three channel one. Ail, Ele, and - no not rudder - throttle!
So I've been messing about in the transmitter settings trying to move the throttle action to the rudder stick!
So far - failing!

Photo's to follow, if anyone is interested in white foam shapes!

Solved the push-rod problem - I found  long-forgotten wire bowden cable in the other spares box. With the wire extracted it threaded in through the tailplane 'saddle' and out into the pod, then thread the carbon rod into the bowden outer, all the way through, and withdraw the nylon? outer again.
Now to get the wire inner back in!!  





 

I'm interested

A follow-on question  - 
The reciever is rated up to 10v, and the servos are specced at 6v
Now, can I run these servos direct from the 2S lipo (7.5v) or will it fry them. I'm struggling to find space for the ubec!
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Friday pm -
As nobody has responded, I decided to try it, and plugged in a couple of scrap servos (sacrificial!)
An unidentified small one worked fine, and a translucent blue one (ten for a pound quality!) was a bit chattery but worked (that could be why it was discarded anyway!)
So I guess the answer is Yes!
I still can't get the tx to switch the data signal from the throttle function to the rudder one, though!

As requested, some photo's of white foam plastic.
Note the enormous weight in grams!

It was never claimed to be a top-class competition model - just a fun 'sport' one.
If you want to frighten yourself, have a look at the prices on here! - 
www.hyperflight.co.uk/products.asp?cat=R...+Hand+Launch+Gliders

On that site, the recommended servo's are £20 each, plus vat etc!

Libelle in use - 

Probably could use a 'Woomera' (Aboriginal throwing stick) but - 
A - it's against the rules
and
B - how do you release the wingtip peg?

If you watch the vid, the wing-tip peg is JUST hooked by two finger-tips, and the release moment decides which way the model goes!

If pushed, I can throw a good tantrum!  

Ignore my previous query, I've got it sorted.
I had a silly thought at O-God-o-Clock, If I unplugged the battery from the B socket, and into the R socket that proved to be T, and plugged the R servo into the B socket - voila!
Ails, Ele, and Rudd on the correct sticks - the receiver plastic sleeve casing is labelled incorrectly!
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Who'd a thunk it! 
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So if I wanted to use the rx AS a 4 chan, I presume I would have to plug in a Y-lead to one of the connectors, so I could have power in, and servo out - on the same pins. Of course there is no mention of this in the brief notes!

I see what you mean - but
That would reduce your acceleration arc to about 100 degrees, instead of 360. Beyond that, you are throwing the model downwards!
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It is also another bit of kit you have to carry about. The whole point of Discus launch is there are two items you need,  a radio and a model - nothing else.