HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Mar 18, 2006, 08:27 PM
blah...
THUREN's Avatar
United States, OR, Bend
Joined Jun 2005
2,932 Posts
Do not get the Thorn in a flat spin!! Serioiusly!

I did a "flick" again today and lets just say........ The solid heavy wings have a mind of their own... Steve(Surfimp) should have a video soon...


Still loving the energy and rugged-ness of this plane!!!

Don
THUREN is offline Find More Posts by THUREN
Reply With Quote
Sign up now
to remove ads between posts
Old Mar 18, 2006, 08:31 PM
Registered User
Daemon's Avatar
Lakewood, Colorado
Joined Aug 2002
27,688 Posts
What'd you do to get out of the spin? I keep thinking that throwing
full flaperons would do it, because it should make the forward moving wing
rise and the stalled or backward moving wing drop which would roll it
knife edge, and then the nose should drop and it start flying again.

ian
Daemon is offline Find More Posts by Daemon
RCG Plus Member
Old Mar 18, 2006, 10:21 PM
blah...
THUREN's Avatar
United States, OR, Bend
Joined Jun 2005
2,932 Posts
Quote:
Originally Posted by Daemon
What'd you do to get out of the spin? I keep thinking that throwing
full flaperons would do it, because it should make the forward moving wing
rise and the stalled or backward moving wing drop which would roll it
knife edge, and then the nose should drop and it start flying again.

ian

What did I do???? Wait, and wait, and wait, and FRIGGIN' WAIT allready!!!

I let the sticks go center and it felt like 5 more spins happened before the nose came down... I may try it again with flapperons out to get it to stop cause' that is a great idea. Really makes sense... I had tons of speed and even waited for a good whie on the climb but it still flipped so fast it looked like a blur to me from what I remember.. Can't wait to see the video and see that it "really" looked like. I'm sure my rearward CG doesn't help here...

I finally have it dialed REALLY well, and I should probably measure my throws for reference, as I am VERY happy with the handling now. Expo really helped the slow the aileron response, and made me stop over correcting... I use only "reverse snap flap" for inverted flight and it needs only 1/8" of forward stick to keep it level..

The Thorn is now my heavy lift only bird and I finally stuck a great landing today. 25mph and over wind and this is what I'm flying...


Don
THUREN is offline Find More Posts by THUREN
Reply With Quote
Old Mar 18, 2006, 10:31 PM
Registered User
Daemon's Avatar
Lakewood, Colorado
Joined Aug 2002
27,688 Posts
How much static camber are you using?
(If you could lay a straight edge across the bottom of the wing onto
the aileron near the root of the wing, and let me know how big
the gap is between edge and wing at the hingeline)

How far back is your CG now?
I had been moving 1/2 oz slug back further and further on the tailboom
and I finally removed that and drilled out about 1 oz of lead from the slug
in the front of the battery bay and can probably go back further.

ian
Daemon is offline Find More Posts by Daemon
RCG Plus Member
Old Mar 18, 2006, 10:56 PM
blah...
THUREN's Avatar
United States, OR, Bend
Joined Jun 2005
2,932 Posts
I'll measure everything tomorrow ian...

I actually think I have about 2mm of reflex static and use about 2mm of snap-flap on a full yank up. I'll also check my "negative snap" as I was doing inverted pumps today.. Really fun!

I think my CG is about 3-5/8" but I'll check for sure tomorrow...
THUREN is offline Find More Posts by THUREN
Reply With Quote
Old Mar 18, 2006, 11:06 PM
Feeling FrSky
surfimp's Avatar
United States, CA, Santa Barbara
Joined Feb 2003
19,942 Posts
Video is coming soon

Definitely a "pants moistening experience"!!!

Steve
surfimp is offline Find More Posts by surfimp
RCG Plus Member
Latest blog entry: Buzz Evo RTF acro glider review
Reply With Quote
Old Mar 19, 2006, 11:36 PM
blah...
THUREN's Avatar
United States, OR, Bend
Joined Jun 2005
2,932 Posts
Gotta' put the "snap" video in this thread...... I do NOT suggest doing this with the Thorn...


"snaprollflickpantsmoistenerwhatchamacallit" MOVIE


It will keep you on your toes for SURE!

Big thanks to Steve for getting the great footage!!!!
THUREN is offline Find More Posts by THUREN
Last edited by THUREN; Mar 19, 2006 at 11:42 PM.
Reply With Quote
Old Mar 20, 2006, 10:04 AM
blah...
THUREN's Avatar
United States, OR, Bend
Joined Jun 2005
2,932 Posts
Throws...

Ok, here's what I have for throws and CG right now as last flown, and I'm very happy with it...

CG= 3-19/32" or 91mm
Static camber = 0. aileron parallel with top of wing TE spacer thing.
Snap flap down(up elevator/down stick)= 6mm
Snap flap up(down elevator/up stick)= 4.5mm
elevator = 5.5mm up/down
aileron = 15mm up, 17mm down at full deflection. very equal at lower throws
aileron expo= 50%(slowing response) very important IMO!
elevator = linear


I have my aileron DR at 50% making 6mm of linear 1/4 stick travel now 3mm.. This made the slow speed handling very much more controlled and prevents me from overcorrecting keeping the heavy energy storing wings in check...

I don't see this changing much as I am very happy with it. If anything changes I'll be sure to post up...

Don

3/21....... edited snap flap down travel to 6mm...
THUREN is offline Find More Posts by THUREN
Last edited by THUREN; Mar 21, 2006 at 10:42 PM.
Reply With Quote
Old Mar 20, 2006, 11:05 AM
Registered User
Daemon's Avatar
Lakewood, Colorado
Joined Aug 2002
27,688 Posts
Argh..

My center "TE spacer thing" is thicker than the aileron. Saying that
the aileron is flat with the top of that tells me nothing at all, because
I don't know if yours is the same thickness as mine.

ian
Daemon is offline Find More Posts by Daemon
RCG Plus Member
Old Mar 20, 2006, 11:39 AM
blah...
THUREN's Avatar
United States, OR, Bend
Joined Jun 2005
2,932 Posts
Quote:
Originally Posted by Daemon
Argh..

My center "TE spacer thing" is thicker than the aileron. Saying that
the aileron is flat with the top of that tells me nothing at all, because
I don't know if yours is the same thickness as mine.

ian
I first tried to measure doing the straight edge under the wing and there is no "straight" surface to reference.

Heres the best way I can explain mine which should be able to relate over fairly easy...

The top surface of the wing has an obvious "dome" shape. I sanded and shaped my TE spacer to follow this dome EXACTLY and you can not tell something was "glued in" there... I made it seamless in the way it flows with the wing. My aileron top surface is exactly parallel with the top surface of this spacer static... Or in other words., the aileron top surface follows the exact imaginary line of the wing top surface...

Don
THUREN is offline Find More Posts by THUREN
Reply With Quote
Old Mar 20, 2006, 01:34 PM
Registered User
Daemon's Avatar
Lakewood, Colorado
Joined Aug 2002
27,688 Posts
Oh well. Mine doesn't. If there's any camber at all, the
straight edge across the bottom trick should only rest on two points.
If that didn't happen for you then you have no camber, and in
fact must have a little bit of reflex. That's a bit odd because
the RG-15 is a cambered airfoil.

ian
Daemon is offline Find More Posts by Daemon
RCG Plus Member
Old Mar 20, 2006, 01:49 PM
fun is the goal
AndreasMergner's Avatar
USA, NY, Albany
Joined Dec 2003
1,556 Posts
Ian,

How about measuring from the fuse wing saddle? The LE and TE should be the same distance from the saddle since it is flat and the wing is 0 degrees (parallel) to the saddle.

Andreas
AndreasMergner is offline Find More Posts by AndreasMergner
Reply With Quote
Old Mar 20, 2006, 02:45 PM
blah...
THUREN's Avatar
United States, OR, Bend
Joined Jun 2005
2,932 Posts
Ian,

No mine is cambered like the RG15 should be...

Ok..... I just did a test to see if "too the eye" you could see what I'm saying. If you sight down the top of the foil from the front out rear of the wing it is very easy to see if the top surfaces ar alighned. My top surface of the aileron follows the natural contour of the top surface of the wing which will leave a cambered surface on the underside. I deflected the aileron and then tried to put it back where it looked "smooth" into the top surface and everytime I turned my radio on I was off by no more than 1mm... Running your hand over the top hingeline it is a very smooth seamless arc. The aileron is not reflexed at all but would be considered if anything about 1mm cambered.

I will try to see if I can get a good side shot picture of where I'm at...

Don
THUREN is offline Find More Posts by THUREN
Reply With Quote
Old Mar 20, 2006, 03:06 PM
Registered User
Daemon's Avatar
Lakewood, Colorado
Joined Aug 2002
27,688 Posts
I don't understand how it can be cambered, but you can't
lay the straight edge over the bottom and see a gap between the
straight edge and the wing.. Like so:


The problem with saying that the top should be smooth, is that it's curved
and making it smooth is just eyeballing it at best. I can't use the center
section as a reference because mine is thicker than the trailing edge so
I'd be sanding it to the shape of the airfoil by eye, and I can't use the lower
edge of it either because it's flat like the rest of the wing saddle, but the
RG-15 airfoil is cambered so they shouldn't line up. That's why I'm looking for
a direct measure of the camber itself. I've done this on many other
planes. Even a rough estimate would be fine.. like 1/16" gap.

ian
Daemon is offline Find More Posts by Daemon
RCG Plus Member
Old Mar 20, 2006, 04:09 PM
blah...
THUREN's Avatar
United States, OR, Bend
Joined Jun 2005
2,932 Posts
Quote:
Originally Posted by Daemon
Even a rough estimate would be fine.. like 1/16" gap.

ian
I'd say 1/16" at the LE of the aileron and more like a 1/32" at the sub TE of the wing...

With a straight-edge under the wing, there is a gap, but not much... It does make it hard to check as one of my wings is very slightly thicker in section at the TE and the ailerons themselves are thinner than the TE of the wing... There is a gap though..... Just a very small one....

Don
THUREN is offline Find More Posts by THUREN
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Different Kind of Slow Stick, "Slow-G" build-n-fly Don Sims Parkflyers 49 Dec 20, 2006 01:32 AM
Fold-n-fly mike glass Foamies (Kits) 8 May 02, 2003 09:13 PM
WTB USAirCore fold n'fly F-16 Majortomski Aircraft - Fuel - Airplanes (FS/W) 0 Mar 06, 2002 09:07 PM
Want to scratch build a fun fly plane. Cay you recommend plans? WilliamSettle Sport Planes 4 Oct 04, 2001 11:29 PM
Why solder ESC's instead of plug-n-fly? J Cubed Power Systems 5 Jun 29, 2001 06:06 AM