HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Jun 04, 2012, 12:12 PM
Registered User
discus.fly's Avatar
United Kingdom, Central Bedfordshire
Joined Jul 2008
85 Posts
Tuck Effect

Ok so moved the cog further forward, flying great hit a large thermal and then found at 1000ft I had no control!

After a few seconds regained control and started a turn to the left but then she then put her nose down and dissapeared at a great turn of speed.

Found her after an extended search. Nose was a right off, interestingly one aerial wire on the Rx was detached and the depron had fractured arround one of the tailerons.

So was this the dreaded tuck effect or not. Not sure if I had control during the dive as could not hear the motor but suspect it was a combination of Rx, Ae wire and the dreaded tuck.
discus.fly is offline Find More Posts by discus.fly
Last edited by discus.fly; Jun 04, 2012 at 12:20 PM.
Reply With Quote
Sign up now
to remove ads between posts
Old Jun 04, 2012, 08:41 PM
Registered User
St Catharines Canada
Joined May 2002
902 Posts
Hope its repairable.

Hard to say what may have been going on at 1k' or whether the tail fracture took place at height or because of the crash. I had a scratch built sailplane fold up flying level into a thermal/mini wind shear once. You should have dive tested for tuck lower down where you could see what was going on. Several dive tests each time picking up more speed and checking how well it responded to up elevator.

Here is something else to confuse the issue. A flat bottomed airfoil when sitting flat will have a degree or 2 of positive angle of attack. After looking at the picture of your plane [nice looking btw] I noticed that the reflex might be enough to give it a negative AoA. The motor in its current location could give it just enough pitch up to compensate for this while under power. Draw an imaginary line through the nose of the foil to the highest part of the reflexed TE and see if it is so. The decalage of the tail should be the same or up a degree.

Richard
The Tellurian is offline Find More Posts by The Tellurian
Reply With Quote
Old Jun 05, 2012, 06:29 AM
Registered User
discus.fly's Avatar
United Kingdom, Central Bedfordshire
Joined Jul 2008
85 Posts
Damage

Had expected to find a pile of Depron but was very surprised to find an more or less intact structure with the wings still intact given that the impact was near vertical.

Wings are repairable but probably best to construct a new fueselarge using the old tail.
discus.fly is offline Find More Posts by discus.fly
Reply With Quote
Old Jun 05, 2012, 07:18 AM
Blue Falcon
bluefalconhollan's Avatar
the Netherlands
Joined Jan 2007
718 Posts
Today I did maiden my EPP seagull. She flies wonderful and gentle. Span 1,75m. I just have to finish some paint.
bluefalconhollan is online now Find More Posts by bluefalconhollan
Reply With Quote
Old Jun 05, 2012, 10:30 AM
Registered User
discus.fly's Avatar
United Kingdom, Central Bedfordshire
Joined Jul 2008
85 Posts
Very nice.

Looks like you have a complex aerofoil. Would be interested to know the design
discus.fly is offline Find More Posts by discus.fly
Reply With Quote
Old Jun 05, 2012, 10:36 AM
Dance the skies...
Tom Frank's Avatar
United States, MA, Walpole
Joined Dec 2003
17,749 Posts
Quote:
Originally Posted by bluefalconhollan View Post
Today I did maiden my EPP seagull. She flies wonderful and gentle. Span 1,75m. I just have to finish some paint.
What a wonderful-looking scratch-build! The spinner emulation of the beak is very clever. I'd like to see some flight video, please, as well as build details.
Tom Frank is offline Find More Posts by Tom Frank
Reply With Quote
Old Jun 05, 2012, 11:49 AM
Registered User
G-LO's Avatar
Va.Beach VA.
Joined Aug 2007
2,148 Posts
Hi Robert. That looks a lot like Lee's gull wing falcon. Very nice!

Can you take some close up pictures of the wings, servo placement, and the way the wings are mounted. I've emailed you pictures of my bird but I'm still at a stand still of what I should do next. I would love more help from you if you don't mind. Thanks*
G-LO is offline Find More Posts by G-LO
Reply With Quote
Old Jun 06, 2012, 03:05 PM
Blue Falcon
bluefalconhollan's Avatar
the Netherlands
Joined Jan 2007
718 Posts
I will ad more details later. Today I did the maiden and film the gull.

https://www.youtube.com/watch?v=WOn3Z4Ax9d4
bluefalconhollan is online now Find More Posts by bluefalconhollan
Reply With Quote
Old Jun 06, 2012, 03:10 PM
Registered User
United States, CA, San Rafael
Joined Mar 2012
131 Posts
Quote:
Originally Posted by bluefalconhollan View Post
Today I did maiden my EPP seagull. She flies wonderful and gentle. Span 1,75m. I just have to finish some paint.
I can't compete with that level of quality!
Where is the CG on yours?
What is your power setup?
Averan is offline Find More Posts by Averan
Reply With Quote
Old Jun 06, 2012, 03:15 PM
Registered User
United States, CA, San Rafael
Joined Mar 2012
131 Posts
split-tail elevons? i'm so jealous it makes me mad! hahaha! dang i gotta redo mine and get it flying.
Averan is offline Find More Posts by Averan
Reply With Quote
Old Jun 06, 2012, 07:16 PM
skumgummi dave
Gresham, OR.
Joined Mar 2004
1,886 Posts
bluefalconhollan:

WOW!
foamdave is offline Find More Posts by foamdave
Reply With Quote
Old Jun 07, 2012, 03:41 AM
Registered User
discus.fly's Avatar
United Kingdom, Central Bedfordshire
Joined Jul 2008
85 Posts
New 160% Eagle

Made a start cutting out a new fuselage for my 160% EPP Eagle. Any advice as to changes to make to avoid the tuck problem I have.

Currently the wing and tail are set at the same angle.
discus.fly is offline Find More Posts by discus.fly
Reply With Quote
Old Jun 07, 2012, 04:47 AM
Blue Falcon
bluefalconhollan's Avatar
the Netherlands
Joined Jan 2007
718 Posts
Quote:
Originally Posted by G-LO View Post
Hi Robert. That looks a lot like Lee's gull wing falcon. Very nice!

Can you take some close up pictures of the wings, servo placement, and the way the wings are mounted. I've emailed you pictures of my bird but I'm still at a stand still of what I should do next. I would love more help from you if you don't mind. Thanks*
Just finished painting. The wings are fixed to the fuselage. The camera part can come off from the fuselage so there is space for the battery. I use a wing aileron and a leading edge-ron, differential controlled.
bluefalconhollan is online now Find More Posts by bluefalconhollan
Reply With Quote
Old Jun 07, 2012, 08:24 AM
What could possibly go wrong?
nickchud's Avatar
Market Harborough
Joined Apr 2006
3,744 Posts
Leading edge-ron? That's a new one for me. Very interesting!

Do you mean a single servo droops the leading edge at the same time as raising the aileron panel and vice versa? What's the benefit?

Whatever it is, it obviously works beautifully.

Cheers

Nick
nickchud is offline Find More Posts by nickchud
Reply With Quote
Old Jun 07, 2012, 08:42 AM
Registered User
G-LO's Avatar
Va.Beach VA.
Joined Aug 2007
2,148 Posts
Thank you very much Robert. Is there a reason why you glued the wings to the fuse as appose to making it detachable? Sorry for the questions. I'm trying move forward with my falcon. I interested in trying something new this go around.

Lastly. Do you have any suggestions based on the pictures I sent you?

Thank you.
G-LO is offline Find More Posts by G-LO
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Why aren`t most foam planes made with EPP or equivalent. Scarey Foamy EDFs 1 Jul 24, 2007 10:20 PM
Planes Built With EPP And Depron. What Would Be Your Favorite. jbj620 3D Flying 10 Dec 05, 2004 07:06 AM
Rave Before n After My new war bird P-51 Mustang(EPP) powder Slope 22 Aug 22, 2003 01:27 PM
hey guys if yous are looking for arf war bird planes seafire Foamies (Kits) 5 Mar 10, 2002 05:41 PM