Project Rays - Hyperbolic Manta - RC Groups
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Jul 07, 2007, 04:25 PM
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Geode's Avatar

Project Rays - Hyperbolic Manta

Here is the twin brother of Manta DLG .....
Last edited by Geode; Jun 12, 2008 at 11:14 AM.
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Jul 07, 2007, 04:29 PM
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Geode's Avatar
- Manta DLG wing planform with reduced chord
- Hyperbolic wing bending
- Conventional balsa build-up wing with diagonal ribs
- Balsa pod with CF rod re-enforcement
- Full flying bagged tail feathers

Control - rudder/elevator

Span - 59 in
Area - 361 sq in
Mass - 8.0 oz (8.4 oz after CG trimming)
Loading - 3.35 oz/sq ft
Last edited by Geode; May 23, 2008 at 09:51 PM.
Jul 08, 2007, 06:16 AM
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kimhey's Avatar
I just love that wing!

Jul 08, 2007, 12:41 PM
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Geode's Avatar
Hi Kim, hope you getting better now and thanks for your nice words.

Some heat gun works on wing tips to get the washout matched for left/right wings and set it ready for harder launch.

I use AG04~AG10 (6.4%~4.7% thickness) airfoils and narrower chord this time. AG04 family is really slippery at current wing loading. Should be getting better launch height. Stay tuned ....
Jul 08, 2007, 01:33 PM
ajroahkni's Avatar
Oh my, it's beautiful! You are an artist!
Jul 08, 2007, 07:34 PM
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Rogo's Avatar
Very nice!

How was the wing bent - during or after spar/rib construction?
Jul 09, 2007, 01:33 AM
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Geode's Avatar
Originally Posted by Rogo
How was the wing bent - during or after spar/rib construction?
Spar, LE and TE are roughly pre-bended on a hyperbolic shaped jig. The final wing planform is assembled on another jig to have all the components aligned precisely.

Jul 09, 2007, 01:37 AM
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Launch Video

Very good weather today for launch trimming. Rendy's launch is true and straight. The launch height is also pretty good. I estimate the launch height most likely greater than 120 ft.

See video for detail ......

Hyperbolic Manta DLG - Part II (1 min 36 sec)
Last edited by Geode; Jun 18, 2008 at 01:59 AM.
Jul 09, 2007, 03:09 PM
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Geode's Avatar
I'm very impressed by the range of AG04 family. It works very nicely on MDLG as well as on 60" DLG. It's a very slippery airfoil. The lauch height is pretty good, very easy to get back from down-wind and still thermal very very well.

I did a quick comparison on AG04 vs. AG12 (popular airfoil for 60" polyhedral DLG's). It doesn't seem to have any major differences between the two. Am I missing something?

Jul 09, 2007, 03:17 PM
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Flight Video

Another video clip .... thermal on softball field. Hope you enjoy.

Last edited by Geode; Jul 09, 2007 at 08:57 PM.
Jul 09, 2007, 08:10 PM
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Hi Geode,
Really great version!
What thickness/width of carbon are you using on the spar?
Also I was'nt able to run your videos.
Great job!
Jul 09, 2007, 08:43 PM
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Geode's Avatar
Spar is similar to Manta 1/4" x 1/16" spruce with additional CF of 1/4" wide and 0.007" thick (this CF is supposed to be used for rib cap instead of the spar).

Seems like it's corrupted during upload. Will reload the video again. Thanks.

If it is still not working, try this
Last edited by Geode; Jul 09, 2007 at 08:59 PM.
Jul 09, 2007, 09:43 PM
ajroahkni's Avatar
Geode - could you share some photos/information of jigs and forming curves with wood/carbon/spars and d-boxes?


Jul 09, 2007, 10:07 PM
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Geode's Avatar

Wing Jigs

Sure, no problem. These jigs are pretty simple to made.

First one is for bending the wing LE/TE and spar. This is cut out of foam. All the LE, TE and spar go into this for a "rough" pre-bending.

The second jig is made out of balsa. This jig has all the angles for each and every rib. Precision is important for this jig to get all the angles right.

I cut the Dbox into two pieces (15" each) just to make the bending easier.
Last edited by Geode; Jul 09, 2007 at 10:15 PM.

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