HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Jul 09, 2012, 09:56 PM
Registered User
United States, AZ, Tucson
Joined Nov 2010
3,980 Posts
Quote:
Originally Posted by Nodd View Post
Yeah sorry just busting your ballz. Glad you liked my build, I see you're big into the DLG scene, nice work on the Katana stuff.

Anyway don't want to stray off topic here. Great to hear our injured bird is back in the air. That was a quick mend.
At least you dont have to deal with delaming! buuuuut I would definitely keep my sights on a composite DLG. All these Guys would definitely agree with me!

But how is the apache treating you? Still havin fun I hope!
Jwmflying14 is online now Find More Posts by Jwmflying14
Reply With Quote
Sign up now
to remove ads between posts
Old Jul 09, 2012, 11:24 PM
Build something.
Nodd's Avatar
United States, CT, Fairfield
Joined Mar 2012
628 Posts
The Apache is the most fun thing I've put together in quite some time. Yeah I flew with a couple of guys from my club who had a Topsky II & a Blaster & yes they flew circles around me (literally). But as an intro to DLG & a fan of built-up balsa ships, I couldn't be happier with the Apache. As you said though I can see me graduating to a composite DLG soon enough but for now I'm content. Got several 5 minute plus flights a couple of days ago & one big boomer, soooo much fun. I'm hooked.

Glad you got back in the air. Go de-stress, work on that form, catch a few bubbles & know that if you break her again, at least now you know how to fix her.
Nodd is offline Find More Posts by Nodd
Reply With Quote
Old Jul 09, 2012, 11:28 PM
Registered User
United States, AZ, Tucson
Joined Nov 2010
3,980 Posts
Good! Your experience is what I experienced with my super mini. Although its a bummer she broke, I wouldnt have gratuated as soon, and for that I am thankful!

If you ever visit AZ make sure to let me know! Although I haven't flown with many of the local gurus I here they are great guys!
Jwmflying14 is online now Find More Posts by Jwmflying14
Reply With Quote
Old Jul 10, 2012, 09:24 AM
Father of Fr3aK, DLG Pilot
tom43004's Avatar
USA, OH, Worthington
Joined May 2002
6,571 Posts
Quote:
Originally Posted by DLGjunkyard View Post
FWIW There does appear to be a stress riser there judging from the two wings posted in this thread. Whats with that? Topsky should consider a doubler spanning out from the root. If it hadnt failed there perhaps the tips would have shown a mark. Just sayin
Agreed. Too many DLGs have a root doubler that ends squarely right next to the flapperon root slot (stobel comes to mind) and that is the place where they almost always fail.

**disclaimer** I'm not saying that this was a tip strike **disclaimer**

I've never, ever seen a tip strike that resulted in any visible damage to the tip... but they always have compressive failures aft of the spar which is a telltale sign.
tom43004 is offline Find More Posts by tom43004
Reply With Quote
Old Jul 10, 2012, 11:56 AM
Registered User
Congress, AZ
Joined Sep 2001
4,505 Posts
JWM,

I use a #22 needle, Pro-set epoxy and about 20% denatured epoxy. I've used the diabetic needle, (much smaller) with MGS epoxy which is thinner than the Pro Set and it works okay.

The West epoxy is just too thick unless really thinned per Dr Drela's advice, and I'm not certain that when it's injected (as opposed to rubbed into the surface) that the thinner can evaporate.

Of course, temp makes a difference as well.

Good luck.

Gary
GaryO is offline Find More Posts by GaryO
Reply With Quote
Old Jul 10, 2012, 12:12 PM
Aurora Builder
United States, MD, Lusby
Joined Nov 2003
3,374 Posts
Quote:
Originally Posted by tom43004 View Post
Agreed. Too many DLGs have a root doubler that ends squarely right next to the flapperon root slot (stobel comes to mind) and that is the place where they almost always fail.

**disclaimer** I'm not saying that this was a tip strike **disclaimer**

I've never, ever seen a tip strike that resulted in any visible damage to the tip... but they always have compressive failures aft of the spar which is a telltale sign.
Tom, I'm a bit confused by this statement. To my knowledge pretty much every DLG wing has some sort of doubler that ends square with the flaperon, aka, a root wrap. The Aurora has one and the Fr3aK has one! But on both our moldies we have a secondary doubler that extends further outboard, so essentially there are 3 layers of fabric at the root transitioning to 2 layers for a few inches and then to 1 layer the rest of the wing span. I assume this secondary doubler is what you think is missing in the TS2 and other planes?

I run the secondary doubler during my skin layups based on my previous experience in building Tabooish wings and the SuperGee II plans. There are other reasons but folding a wing at the root is not a big concern of mine on the current structure.
samc99us is offline Find More Posts by samc99us
Last edited by samc99us; Jul 10, 2012 at 12:34 PM.
Reply With Quote
Old Jul 10, 2012, 12:39 PM
Father of Fr3aK, DLG Pilot
tom43004's Avatar
USA, OH, Worthington
Joined May 2002
6,571 Posts
Quote:
Originally Posted by samc99us View Post
Tom, I'm a bit confused by this statement. To my knowledge pretty much every DLG wing has some sort of doubler that ends square with the flaperon, aka, a root wrap. The Aurora has one and the Fr3aK has one! But on both our moldies we have a secondary doubler that extends further outboard, so essentially there are 3 layers of fabric at the root transitioning to 2 layers for a few inches and then to 1 layer the rest of the wing span. I assume this secondary doubler is what you think is missing in the TS2 and other planes?
Sam,

The Fr3aK has a joiner wrap and a root doubler. They're different, and serve different purposes.

The root doubler should provide torsional stiffness at the root of the wing. It provides a doubler over the servo area as well. In some airplanes this is not symmetric from top to bottom which always confused me since the need is there for both.

The joiner wrap pretty much only provides a distribution of loads to the skins from joining the wings and attachment of the wings to the fuselage.

The term "doubler" can be confusing though... sometimes it's just a heavier SINGLE piece of material rather than two pieces.

My problem is with airplanes that have a square termination of this "doubler" and especially those that do not extend this termination beyond the flapperon root slot span wise. Especially in a molded ship but also to an extent on a bagger, there is torsional load on the wing during the launch sequence that the spar alone can't sufficiently handle.

I pick on the Stobel because we've all seen them fold and they always go at the same spot. The TS seems to have the same design feature, in front of the flapperon root slot.

I don't want to derail this discussion with too much detail... but it's one design element that seriously bugs me with a few of the ships out there.
tom43004 is offline Find More Posts by tom43004
Reply With Quote
Old Jul 10, 2012, 12:42 PM
Will fly for food
davidjensen's Avatar
Bellevue WA,
Joined Dec 2003
6,481 Posts
The new (all carbon) TS3 wing has a root doubler.
davidjensen is offline Find More Posts by davidjensen
Reply With Quote
Old Jul 18, 2012, 07:38 PM
Registered User
United States, AZ, Tucson
Joined Nov 2010
3,980 Posts
Well, I'm back!

Don't worry, its not in the same place.But it is the same wing halve! Every day I go fly I have been inspecting fdor delamination ever since my last fiasco. Today I discovered anarea completely delaminated in the center of the wing halve. It's 8 inches by 6 inche. Which is huge! Is this wing half just defective? Now I truely believe the first incident was not a wing strike!

I'll post pics soon, its a huge delam, and this time injecting glue didn't seem to work!
Jwmflying14 is online now Find More Posts by Jwmflying14
Reply With Quote
Old Jul 18, 2012, 09:45 PM
Registered User
iwokeupwithgills's Avatar
United States, NM, Albuquerque
Joined Nov 2011
150 Posts
Bummer dude. You still gonna come out to BTH?
iwokeupwithgills is offline Find More Posts by iwokeupwithgills
Reply With Quote
Old Jul 18, 2012, 09:55 PM
Now fortified with carbon
DLGjunkyard's Avatar
Canada, ON, Puslinch
Joined Apr 2010
2,614 Posts
I wonder if they bagged it with a bunch of fur still on the foam. Sounds like the skin to foam bond is poor
DLGjunkyard is offline Find More Posts by DLGjunkyard
Reply With Quote
Old Jul 18, 2012, 10:07 PM
Registered User
United States, AZ, Tucson
Joined Nov 2010
3,980 Posts
Here are two pics.

The first is no stress at all on the wing. The second is just barely any stress on the wing, just enough to show. The whole area is about 8" long (root to tip) and about 6" thick.
Jwmflying14 is online now Find More Posts by Jwmflying14
Reply With Quote
Old Jul 18, 2012, 10:10 PM
Registered User
United States, AZ, Tucson
Joined Nov 2010
3,980 Posts
Now I am truely upset..... St least last time there was a chance it was my fault, now I know this is just a poorly made wing. The other side is great though! Just a bummer since wings are so expensive. Might as well get another DLG instead..... I really hope I am the only one who got a bad wing, cause this is very disappointing.
Jwmflying14 is online now Find More Posts by Jwmflying14
Reply With Quote
Old Jul 18, 2012, 10:28 PM
Thermal, where art thou?
BavarianCharles's Avatar
85045
Joined Oct 2005
2,451 Posts
Crunchy Ytopsky

Quote:
Originally Posted by iwokeupwithgills View Post
Bummer dude. You still gonna come out to BTH?
Don't let this prevent you from joining us at the BTH, and bring the plane, even if - or especially if - it's still busted. We'll take a good look, and keep you busy timing. There's a lot to learn, so let's get started.

The Topsky wing, just like the Predator, does not have spars or rods. Both rely on on two layers of carbon cloth top and bottom for strength, and failures tend to be catastrophic. This type of construction tends to magnify small manufacturing errors. I use a similar construction method one my home-built wings, but exercise a lot of care during the laminating process, while you're at the mercy of someone in Taiwan, having good and bad days. A small area with poor adhesion between the foam and the fabric will silently grow, like a cancer, until it fails with seemingly little effort. By all means, contact your vendor, and ask for a good deal on a replacement wing. They don't build them, and mean well, so work with them to resolve this issue.

See you on Saturday, I hope.

BavarianCharles is offline Find More Posts by BavarianCharles
Reply With Quote
Old Jul 18, 2012, 10:41 PM
Registered User
United States, AZ, Tucson
Joined Nov 2010
3,980 Posts
Quote:
Originally Posted by BavarianCharles View Post
Don't let this prevent you from joining us at the BTH, and bring the plane, even if - or especially if - it's still busted. We'll take a good look, and keep you busy timing. There's a lot to learn, so let's get started.

The Topsky wing, just like the Predator, does not have spars or rods. Both rely on on two layers of carbon cloth top and bottom for strength, and failures tend to be catastrophic. This type of construction tends to magnify small manufacturing errors. I use a similar construction method one my home-built wings, but exercise a lot of care during the laminating process, while you're at the mercy of someone in Taiwan, having good and bad days. A small area with poor adhesion between the foam and the fabric will silently grow, like a cancer, until it fails with seemingly little effort. By all means, contact your vendor, and ask for a good deal on a replacement wing. They don't build them, and mean well, so work with them to resolve this issue.

See you on Saturday, I hope.

Thank you! I will still try to get it fixed by the weekend. It's just a major bummer, and huge disappointment. The problem is I already got a good deal on this airframe as this whole airframe was a replacement.
Jwmflying14 is online now Find More Posts by Jwmflying14
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Question How Does This Y6 Setup Sound? AEMontoya Multirotor Talk 2 Jun 21, 2012 03:06 AM
Rant How does this Happen?!?!?!?! bakon Scratchbuilt Indoor and Micro Models 26 Feb 02, 2011 05:17 PM
Help! Lipo Survives 4 Days into a Dead Short !!!!! How does this happen ??? JettPilot Batteries and Chargers 18 Sep 20, 2009 10:48 AM
Discussion how does this happen??? gwinhh Chit Chat 0 Jul 22, 2007 02:39 PM
How does this happen to a Lipo? kushal_22 Parkflyers 11 Jul 06, 2003 05:01 PM