SMALL - espritmodel.com SMALL - Telemetry SMALL - Radio
Reply
Thread Tools
Old Oct 13, 2011, 11:27 PM
cmorton
Tucson, AZ
Joined Feb 2008
57 Posts
xxx
dumbdidgits is offline Find More Posts by dumbdidgits
Last edited by dumbdidgits; Nov 09, 2012 at 10:20 PM. Reason: embarased of my lack of knowedge for wings
Reply With Quote
Sign up now
to remove ads between posts
Old Oct 14, 2011, 04:03 AM
the answer 42 is
Switzerland, AG, Lenzburg
Joined Jan 2006
1,904 Posts
the flaps will help you to thermal better, even on a FW, it needs some adjustment by it pays off, and yes very dumb idea, FW normaly use anhedral (negative dihedral) and most importantly do not change a proven design.

just my two cents

EZ
Edwinzea is offline Find More Posts by Edwinzea
Reply With Quote
Old Oct 18, 2011, 07:00 PM
Registered User
ZachAttach's Avatar
United States, CA, Long Beach
Joined Mar 2011
73 Posts
I agree with TheGuyInTheHat. Dihedral is tempting from a spiral stability standpoint, and it would take about 5 degrees to achieve this (based on simulation). However, side gusts create unwanted rolling moment on a swept wing, and anhedral would help reduce this. I've flown around with the winglets down and it did track slightly better, but the landings were problematic.

When theremalling, the Z1 will slowly roll itself inwards if you only give it pitch input. After three revolutions there’s probably about 10-degrees of extra bank if left unchecked. This is really easy to correct for though. The slight opposite-stick actually helps the wing turn tighter, by adding more drag (aileron down) to the inside.

On the flaps, I've played around with them some when thermalling. I don't think there is a real benefit from a sink-rate standpoint, but they do allow for lower flight speeds and tighter circles, so I can see how a good pilot could make use of them, especially in really small thermals.

Zach
ZachAttach is offline Find More Posts by ZachAttach
Site Sponsor
Reply With Quote
Old Oct 26, 2011, 12:34 PM
Registered User
USA, CA,
Joined May 2001
1,754 Posts
Thats is a fantastic Flying Wing, I want to try one!!
Joe
Joe Pierson is offline Find More Posts by Joe Pierson
Reply With Quote
Old Oct 26, 2011, 04:09 PM
internet gadfly
nmasters's Avatar
Colorado
Joined Aug 2006
2,192 Posts
Quote:
Originally Posted by ZachAttach View Post
I agree with TheGuyInTheHat. Dihedral is tempting from a spiral stability standpoint, and it would take about 5 degrees to achieve this (based on simulation). However, side gusts create unwanted rolling moment on a swept wing, and anhedral would help reduce this. I've flown around with the winglets down and it did track slightly better, but the landings were problematic.
Hi, Zach--

Here's another trick you could try with the winglets to adjust the skid/roll and skid/yaw moments. Canting the winglet inward so the inner surface is tangent to a circle centered on, or even a bit below, the CG will have ta similar effect as an anhedral tip. Burt Rutan uses this on the LongEZ. Many of the tricks umm "techniques" that work for the swept main wing of canards also work for flying wings. Four or five posts in the canard thread after this post talk about spiral stability

--Norm
nmasters is online now Find More Posts by nmasters
Reply With Quote
Old Oct 26, 2011, 08:44 PM
Detail Freak
target's Avatar
Harbor City, CA
Joined Oct 2003
21,853 Posts
I'd be very interested in a larger Z1, about 100" and a 2 pc wing design....

I'm also willing to bag cores myself, you provide the cores, beds and design.

R,
Target

PS. What kind of launching for thermalling has been done? How well does it launch? Any video?
target is offline Find More Posts by target
Reply With Quote
Old Oct 27, 2011, 03:09 AM
Registered User
ZachAttach's Avatar
United States, CA, Long Beach
Joined Mar 2011
73 Posts
Norm,
Thanks for the link and ideas. I'll try some different winglet angles and see how it goes.

Target,
I agree on the 2 pc for a larger one, and regarding the cores, I'll send you a PM.
On launching, you can toss it from the trailing edge, which is pretty close to the CG. Getting it up high from a toss requires some technique though. You can get it up 60 ft or so with some practice, but a bungee launch may make more sense: 30 second mark on this video. For hand launches in no wind, I've been using a more aggressive version of the launch 15 seconds into this video.

Zach
ZachAttach is offline Find More Posts by ZachAttach
Site Sponsor
Reply With Quote
Old Jan 06, 2012, 01:18 PM
Proud member of LISF and ESL
LI, New York, USA
Joined Mar 2003
24,549 Posts
This looks very interesting. I am surpriased to see a pure glider in the elecric airplane forum. Is there a discussion in the glider section somewhere? I can't find it.

It clearly is a slope glider but there are a few posts that suggest this is a good thermal soaring wing too. Can someone share more on this?

I am a thermal pilot first, slope pilot second and sometimes I fly electric airplanes, but not often.

So tell me more about this as a thermal glider.

How are you launching it? I see a zip launch from the nose using a bungee/hi-start, but the launch doesn't look very high. How about a "nomral" altitude optimized hi-start launch?

Can it stand up to a winch? I have tried to launch slope flying wings on a winch placing a hook near the CG, but they generally will not stay on the hook. Can you winch this?
aeajr is online now Find More Posts by aeajr
Last edited by aeajr; Jan 06, 2012 at 01:28 PM.
Reply With Quote
Old Jan 06, 2012, 01:42 PM
Detail Freak
target's Avatar
Harbor City, CA
Joined Oct 2003
21,853 Posts
Ed-

In my opinion, you will never make a tailless design launch anywhere nearly as high as a tailed design, since you cant effectively camber the wing.
Still, it has some "coolness factor" and is very unique.

I know that the gentleman that does RCSD has a flying wing that he's launched a bunch for thermal, you could probably get some good insight from him.


R,
Target
target is offline Find More Posts by target
Reply With Quote
Old Jan 06, 2012, 01:56 PM
Proud member of LISF and ESL
LI, New York, USA
Joined Mar 2003
24,549 Posts
Is there any kind of spar in this wing or is it more of a stressed skin design?
aeajr is online now Find More Posts by aeajr
Reply With Quote
Old Jan 06, 2012, 01:56 PM
internet gadfly
nmasters's Avatar
Colorado
Joined Aug 2006
2,192 Posts
Quote:
Originally Posted by aeajr View Post
This looks very interesting. I am surpriased to see a pure glider in the elecric airplane forum. Is there a discussion in the glider section somewhere? I can't find it.
Since the electric flying wing forum has been the only flying wing forum on RCG it's kind of become a catchall tailless forum. Some guys place there flying wing build logs in other fora depending on the power plant or flying style, and that's ok, but it makes it harder to find all the really interesting flying wing threads. As you may have noticed this forum is dominated by high power, low aspect ratio, flying machines (little missiles with large fins) with no similarity to full scale airplanes. A new forum has been started that appears to be devoted to machines that fly on the wing rather than on the engine.

--Norm
nmasters is online now Find More Posts by nmasters
Reply With Quote
Old Jan 06, 2012, 02:18 PM
I make planes I want to fly
Mid7night's Avatar
Southern Cal.
Joined Mar 2004
552 Posts
Just thought I'd pop in and leave this here. I started working on my own Z1 over the holidays...actually I haven't even started on the wing at all, I've been sidetracked by my own, addition.

Why? Because I had parts lying around that I wanted to do something with. Namely a duct, a few rotors and a couple 4800Kv inrunners. :P

So all I needed was an airplane, and along came Zach. Then all I needed was a way to attach said 'extra bits' to the awesome aircraft, and thus began my pylon project. Zach also recently suggested a neat way to attach the pylon in an elegant and removable (i.e. repairable!) way...more on that later.

Yes, the duct is ugly. And yes, I am thinking about making a nice nacelle/faring to go around it to cover up the zip-ties...we'll see how tricky I want to get with that extra styrofoam I've got.

Click for imgur album of the process so far

Mid7night is online now Find More Posts by Mid7night
Reply With Quote
Old Jan 09, 2012, 10:56 AM
Registered User
xrx1113's Avatar
United States, FL, Lehigh Acres
Joined Aug 2011
863 Posts
I have my Z1 it is beautiful now i just need to build it. im trying to decide on flaps or not. I am flying flatland and dont have a space issue for landing and have never seen a wing you couldnt land at your feet anyway. I'm leaning towards keeping it as light as possible and not doing the flaps; anyone out there have an opinion one way or the other.

that DF is interesting i just went with zacks motor pod and a small 300 size outrunner.
xrx1113 is online now Find More Posts by xrx1113
Last edited by xrx1113; Jan 10, 2012 at 02:33 AM.
Reply With Quote
Old Jan 09, 2012, 04:09 PM
Keep calm and don't blink
KiwiKid's Avatar
Hamilton, New Zealand
Joined Jun 2005
2,092 Posts
Just received mine too - great crafting. I was looking into the flap issue also, but decided the real uniqueness of this model is the fact that it is a wing built like a lightweight DLG and this would be compromised to an extent by adding the weight of flap servos and wiring. I have several smallish suburban soaring sites where I plan to fly the model and look forward to thermaling it off a bungy launch, so weight is an issue and the benefit to be gained from flaps don't really outweigh the weight penalty for my purposes.
KiwiKid is offline Find More Posts by KiwiKid
RCG Plus Member
Latest blog entry: SLS for the Calypso Cobra
Reply With Quote
Old Jan 10, 2012, 01:24 AM
Registered User
ZachAttach's Avatar
United States, CA, Long Beach
Joined Mar 2011
73 Posts
I agree. The flaps are effective if you need to land in a small or lifty area, like the top of a slope. Otherwise, they may not be worth the extra weight and drag if you are flatland thermalling. I don't have them on the Z1 I'm flying now because the wind and thermals are weak this time of year.

I'm not a big fan of the power pod either because the added weight really hurts the sink rate. I guess it makes sense if there is no chance of soaring or if you need to get really high to find the lift.

Zach
ZachAttach is offline Find More Posts by ZachAttach
Site Sponsor
Reply With Quote
Reply


Thread Tools