RCSchims: TsWing - a flying wing made out of Twinstar2's Wings - RC Groups
Thread Tools
Jul 03, 2010, 10:19 AM
Austrian FPV Freak
schim's Avatar
Build Log

RCSchims: TsWing - a flying wing made out of Twinstar2's Wings


Hi everyone!
First I want to share my few details about a project I had in mind some time now:

Materials:

Twinstar 2 spare Wings
960kv BL Motor (orig. from Parkzone P51 Gunfighter) + orig. ESC (18amp)
2 carbon rods (one 1m, one about 20cm)
2 16g servos (MPX Tiny)
3 ch rx (I had a 7ch available)

Tech specs:
Wingspan: 119cm / 47inches
AuW: 730g (with 1800mah battery)
Motor: 960kv - about 700g thrust
Prop: 9x6,5
CG: 17-20cm
Wingroot 25cm Wintip 23cm
50degree arrowshape
a bit up-thrust in the motormount

The good thing: the build was very easy. For example I attached the motormount just with cable ties through the wing on the carbon rods (see the pictures down to see what I mean).
The thing can look good if some nice taping is applied...

The bad thing:
my "invention" doesn't really fly :-(
I used some CG calcs and entered the dimensions of my wing and then came to about 17-20cm from the leading edge. I used the position of the battery to adjust the cg, but as you can see in the vid: shortly after takeoff it dives down as if the CG was way to much in the front...

Question: can the profile of the Twinstar wing be "incompatible" to be a flying wing? Basicly I just glued the cores together after I had cut them 25deg each - giving me 50deg arrow shape.

Please give me some hints on what I've done wrong here!
How to start a Flying Wing and not chop off your fingers... (1 min 1 sec)


Maiden flight and Fotos here
Fotos alone: http://picasaweb.google.com/Schimpic...eat=directlink


Thanks,
RCSchim
Last edited by schim; Jul 03, 2010 at 10:32 AM.
Sign up now
to remove ads between posts
Jul 03, 2010, 10:29 AM
Registered User
From the flight video it looks like your cog it too far back. The wing is very pitchy. Your wing does not have a lot a sweep and you have a heavy motor on the back. You might want to go with a heavier battery and stick it way out on the nose and try that. Also when you throw the plane you can throw it like you did at first just have the motor off until it leaves your hand.
Jul 03, 2010, 11:02 AM
Registered User
How much reflex are you using on your elevons? I didn't notice any in your photos.

If you launch inverted, does it perform an inside loop, as opposed to the outside loop it executes from the upright launch?
Last edited by DT56; Jul 03, 2010 at 04:50 PM.
Jul 03, 2010, 11:58 AM
Where the hell is Biggles
Nederland's Avatar
You guys in Austria say F also,,,,Wunderbar
I tried something like this recently with the wings of a Double Blitz glider.
It did the same thing exactly,, I think it was because I hadn't dialed in LOTS of reflex.
Jul 03, 2010, 04:59 PM
Registered User
Prop stitches's Avatar
I had a simular problem with one of my wings, and I found that the motor had just a little down thrust in it. I got it to zero thrust angle and zero offset angle, and now it flies fine.
Prop s
Jul 03, 2010, 06:44 PM
Registered User
meshyx's Avatar
I also think that it is tail-heavy. Try putting a heavy battery right at the tip and see if it will glide with slightly reflexed (up) elevons, maybe 0.5 to 1 cm up.

A launch tip: I throw my wings (up to 1.8m wingspan) with a left-armed sidearm throw... how should I explain it... Hold the wing like you're carrying a briefcase, by the tip, with fingers on top and thumb on bottom, so the bottom side of the wing is towards your leg.
Then change grip placement so you're holding it halfway out the right wing. Then just lift your hand straight out and give it a gentle throw while turning your body. No running needed, certainly

HAH, I know I should have looked on youtube first, here's a video:
How to launch a flying wing safely (0 min 21 sec)
Jul 04, 2010, 07:02 AM
Austrian FPV Freak
schim's Avatar
OK - it flew for MINUTES!!!
It isn't trimmed out perfect and not yet super stable - but at least I was able to keep the wing up in the air!

I moved the 1800mah (150gr) battery all the way to the front - so my CG was about 16,5cm and I had to use a lot of uptrimm!
I know this is no perfect solution - because it has more drag this way (I had use nearly full up elevator to get level flight without motor).
When useing the motor and flying a bit faster it gets more stable. Its fun to fly (if I get rid of being super nervous not to smash my selfbuilt wing into the ground).

Full throttle with this motor is way enough power and will surely make it great to fly once it's trimmed better.

TsWing MaidenflightNr2 (Flying Wing finally flies!) (3 min 44 sec)


Thanks again for your help!

BR,
RCSchim
http://rcschim.blogspot.com
Last edited by schim; Jul 05, 2010 at 07:26 AM.


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Flying wing using chunky wings A74Charger Flying Wings 19 Apr 06, 2010 01:13 PM
Discussion "wing" out of jet wings ?? Erroet Flying Wings 20 Feb 08, 2010 07:23 PM
Whoops! AirfoilZ Yak 54 cracked in half and made into flying wing :) dylantorquerol Foamies (Kits) 6 Feb 03, 2010 08:29 PM
Yippee! I Think We've Made it! Flying Wings Forum! jimsky Flying Wings 31 Jun 13, 2004 11:25 AM