My X8 launcher

[Coyote]

Ive moved the hook 3cm further forward from its previous 50% between nose and CG. Without pulling the whole thing apart its about the only place I could have put it. So Ill try again soon without chute

[skyscraper]

Ive moved the hook 3cm further forward from its previous 50% between nose and CG. Without pulling the whole thing apart its about the only place I could have put it. So Ill try again soon without chute

Just wondering... Did this mod work out? Does it work now without the chute?

regrads
Andy

[Coyote]

Due to the rubbish weather, I`ve not been back out with it to try it out

[Captain Birdseye]

Hi, I stumbled across this thread and it seems to answer my prayers! I have  a non FPV (so far anyway!?) Habu 32 Foam Ducty and it is awkward to launch. I wondered what the practicalities of a catapult launch would be?

Any thoughts welcome.

[Skipper Billy]

The bungee launcher will have you airborne consistently and reliable every time.

If you need any help just shout. It was my launcher that inspired Coyote.

X8 Maiden Flight - Alba Aviation

[MarkLincs]

I really need one building :)

My x8 has been sat around for way to long and its next onto the work top sort to fly

its the mechanism I need building I can buy the launch tubes etc etc

[Coyote]

I just used a nail and a piece of wood hinged with a hole in it, simplez :)

[Captain Birdseye]

Thanks Billy,
I get the general drift of the plastic pipe frame, the 'dark art' details I guess are length and strength and stretch of Bungee, shape and position of hook, is the 'chute critical? and how to fasten/release the model at launch. What I could really do with is seeing it in action in the plastic ?

[Skipper Billy]

No dark art or smoke and mirrors - just a little experimentation tainted with initial failure  ;) ;)

The bungee is easily available from here - http://www.hobbyking.com/hobbyking/store/__10609__HobbyKing_8mm_Silicon_Rubber_Bungee_Hi_Start_Cord.html  1 length for planes up to 2kg - two lengths side by side for up to 4kg

Get a luggage scale for weighing suitcases and attach it to the end - you want pull of about 3 - 4 times the weight of the plane - count how many paces that is then you can easily replicate it without the scales.

The hook on the plane wants to be about 50% from nose to CofG - its not that critical.

The hook needs to be capable of suspending 3 - 4 times the weight of the plane (metal coat hanger) and angled down about 45 degrees to the ring can slip off easily. I don't bother with para - just a bit of coloured cord so I can see when its released.

I posted a load of detail photos somewhere on here - have a search for bungee or launcher you should be able to find it - if not I will repost the photos when I get home tonight. My release mechanism is quite sophisticated - Coyotes works just as well and is much simpler to make.

[Captain Birdseye]

Ok, that all makes perfect sense, I found your previous thread. My 'plane is 1.5 Kgs so a single length should suffice. Pace it out to 6 ish kilos of pull, stand well back and press the pedal?
Being a ducted fan I guess full throttle before release?

Thanks again.

[Skipper Billy]

6kg is more than enough - 4 - 5 would do it - with a ducted fan not only full throttle but wait until it comes on the pipe before pressing the pedal!!

Good luck.

[Captain Birdseye]

Gathering up all the bits to build. One thing strikes me, the rope splits close to the 'plane end and one half goes to the release mechanism, the other goes to the hook on the 'plane. Would there me any merit in including a short length of bungee in the rope going to the model to reduce te sudden shock/snatch when the bungee is released?

[Coyote]

Not really, you want the full power straight away to get the plane to come off the ramp and get its speed up. As soon as the plane is off the ramp the bungees stored power drops off very quickly so you want to utilize all the stored energy straight away.