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Old Jul 14, 2009, 03:17 PM
Build, fly, crash. Repeat.
Goeland86's Avatar
Switzerland, Canton of Neuchâtel, Neuchâtel
Joined Feb 2007
652 Posts
ok, so the maiden had to be postponed because of an unsolved repeated range check failure. It's driving me crazy. Must be all that carbon on the tray itself that's getting in the way. I'll figure it out, one way or another.
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Old Jul 15, 2009, 04:39 PM
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Thermaln2's Avatar
Reno Nevada
Joined Oct 2007
2,590 Posts
You could try shortening the pod a bit more, mounting the servos in the fusleage and then passing the control rods out the back end to the ailerons. all you would have to do is disconnect/connect the linkage, per the Predator II.



Quote:
Originally Posted by Goeland86
It stunned, it amazed, and best of all, it FLEW!

Well, sort of. I managed to get a feel for the need to shim the wing to the right angle - compensated today by just using way too much elevator trim.

Geode, I have to say - amazing work on that design! All I did was build it as close as I could (which was probably not very) to what you'd sent me, and a gentle hand toss and it crossed the length of a baseball field! (not on the diagonal though, don't be too pushy!)

I haven't weighed it yet - I finished the aileron linkage at 3 AM last night, so I figure I deserve a little bit of rest before I get all the details out. But I thought you'd like to see pictures

And now, for the piccies!
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Old Jul 15, 2009, 04:48 PM
Build, fly, crash. Repeat.
Goeland86's Avatar
Switzerland, Canton of Neuchâtel, Neuchâtel
Joined Feb 2007
652 Posts
I already have nose weight, and shortening the nose won't help my tail heaviness any...

As far as the ailerons go - I could have put the servos in the pod, but I built them in the wing and have a Deans 4 plug connector + wiring harness taking care of that.

The pod is about 10 mm shorter than what Geode's design called for, and my boom is a little longer (supposed to straighten out launches if my DLG mentor hasn't lied to me), so I'm quite happy with the plane as it stands.

Goe
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Old Jul 15, 2009, 05:46 PM
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Thermaln2's Avatar
Reno Nevada
Joined Oct 2007
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Quote:
Originally Posted by Goeland86
I already have nose weight, and shortening the nose won't help my tail heaviness any...

Goe

There is a misunderstanding. The pod was layed up so that the length under the wing can be shortened. The Nose does not need be shortened. The back end is left open, and the pod was not meant to support the tailboom in any way. The spline has a shaped section that was designed to wrap a bit more around the tailboom, thus increasing the gluing area. The pod was meant originally to be a shell, and the front would come off much like Watson's designs.
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Old Jul 15, 2009, 05:47 PM
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Reno Nevada
Joined Oct 2007
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Quote:
Originally Posted by Goeland86
(supposed to straighten out launches if my DLG mentor hasn't lied to me)

Goe

Not DLGDude, hopefully, duhhh.
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Old Jul 15, 2009, 06:01 PM
Build, fly, crash. Repeat.
Goeland86's Avatar
Switzerland, Canton of Neuchâtel, Neuchâtel
Joined Feb 2007
652 Posts
Uh, actually, it is DLGdude... So far I've been doing ok under his guidance. Only started flying DLGs in april, and I've come a long way already.

As for the use of the pod - well, I like the fact it slips off better - makes it very interesting and keeps the whole thing really sturdy. I added a small piece of velcro at the bottom of the end of the pod where I had a piece of tape on the picture. Makes it easier and avoids wasting tape. The pod is now just an aerodynamic shell, and there's easy access to all of the radio gear with plenty of room.
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Old Jul 19, 2009, 04:44 PM
Build, fly, crash. Repeat.
Goeland86's Avatar
Switzerland, Canton of Neuchâtel, Neuchâtel
Joined Feb 2007
652 Posts
Geode, I have a little anecdote that I think is important for you to know.

Yesterday I took the manta out to a friendly competition in Long Beach. A dozen pilots total. In the 3rd round, on launch, my stab flies off - it was my bad for making a bad stab pylon, but here's the interesting bit.

As the stab flies off, I lost all control over the plane, obviously. But it's still heading upwards at about a 45 degree angle. While it's climbing, I'm trying to put it on it's side, and use the rudder instead. That didn't quite work, and it just ended up inverted. Well, at this point, I figure it's worth trying anything, so I pull the flaps out full.

At this point the plane was already at the top of it's trajectory and started heading down. But when I pulled the flaps it not only slowed the plane, it also softened the descent angle. The plane landed, while a little harder than I'd normally want, WITHOUT another scratch!

I think this attests to the quality of the design you put together, since it was able to somehow keep flying while inverted, with no stab on. Admittedly I'm not going to try to repeat the experience anytime soon - but if you have the right reflexes, and a bit of luck, this plane can handle pretty much anything!

Now I'm going to work on a better stab mount and a better stab altogether.

Cheers!
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Old Jul 19, 2009, 11:03 PM
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Geode's Avatar
San Jose, CA
Joined Jan 2007
795 Posts
Wow! that's quite an interesting "experiment". Great to hear that you made the perfect right moves to get it down safely.

A Manta wing with reflex and without stab ......

Manta Flying Wing (Composite Version) (2 min 28 sec)


It took me sometime to get this thing right, but you just make it happen and seems so easy. Congratulations for your safe landing.

Geode
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Old Jul 19, 2009, 11:38 PM
Build, fly, crash. Repeat.
Goeland86's Avatar
Switzerland, Canton of Neuchâtel, Neuchâtel
Joined Feb 2007
652 Posts
Now I'm curious as to where you set the CG on that flying wing. It's the same wing as the one on the DLG right?

Because if it is, and the CG's in a somewhat similar spot, then it explains why I managed to bring it down safely.
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Old Jul 21, 2009, 01:51 AM
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Geode's Avatar
San Jose, CA
Joined Jan 2007
795 Posts
Flying wing has CG ahead of regular DLG and with reflex airfoil to maintain stability control.

In your case, once the tail has been removed, the CG will move one step closer to flying wing CG. Combined with the inverted flight with flap (reflex in reality) make it manage-able for a safe landing.
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Old Jul 21, 2009, 01:54 AM
Build, fly, crash. Repeat.
Goeland86's Avatar
Switzerland, Canton of Neuchâtel, Neuchâtel
Joined Feb 2007
652 Posts
Yeah, that actually makes sense.

Cool. But like I said, not something I want to try again
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Old Jul 21, 2009, 09:59 PM
It's a mere flesh wound!
Buddy Roos's Avatar
Woodstock,Ga.
Joined Jun 2004
1,134 Posts
I've seen the "drop the flaps a little and flip it inverted" method used many times to save a sailplane in TD competition when the stabs came off. One of my friends had his stabs come off twice in contests and used the method to save his plane both times.

The big thing is to have the presence of mind to think about it under stress. Some guys just freeze up and stand there and watch until their plane hits the ground without making any attempt to save it.

Buddy
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Old Jul 22, 2009, 08:33 AM
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Geode's Avatar
San Jose, CA
Joined Jan 2007
795 Posts
The "drop-flap" setting during lunch for TD serves perfectly well as "reflex" in this kind of accident.

Geode
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Old Jul 22, 2009, 01:37 PM
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gershon's Avatar
Joined Jul 2009
3 Posts
Hi Geode!

I built the Manta and the final flight weight is 256 gr. I have already flown with it for 3 days, and the weight is now finalized, because at first time I fixed the control of the balance elevator with rubber-fishing line combination but it was very weak, so I changed down that to control rod. It means plus 6g and I had to add further weight to the nose so it stopped in 270 gr.

Attached you can find some pictures from the plane.

Gershon
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Last edited by gershon; Jul 22, 2009 at 02:11 PM.
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Old Jul 22, 2009, 06:03 PM
.: Looking for Thermals :.
Ricardo RW's Avatar
Chile, Quinta Región de Valparaíso, Los Andes
Joined Jun 2002
864 Posts
Gershon, is that a wood pod? Could you please post pictures to get more detail?

Nice work BTW.
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