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Old Feb 02, 2009, 07:33 AM
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Doug- next time smile for the picture!! Fortunately I know you and have seen the product from beginning to end! Fantastic!. NMN
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Old Feb 02, 2009, 07:42 AM
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Cougar01

Quote:
Originally Posted by Cougar01
Doug- next time smile for the picture!! Fortunately I know you and have seen the product from beginning to end! Fantastic!. NMN
the one constant in my universe is that I will always do things because of my wife (most of them good) but I must say I am suprized at the people she sends X's and O's to. Deut.
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Old Feb 03, 2009, 11:20 PM
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Wow - awesome job!
Thanks for taking the time to share that project, very inspirational indeed.
I have a little tech question if I may?
Do you recall the CG location at all?

I'm doing a scale version of the same but at only 48" span & any info would be handy.

Cheers - Phil
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Old Feb 04, 2009, 02:33 AM
HDL
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Metz, France
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Amazing !

I just discovered Your amazing job Doug...

I'm also about to build a similar model in mixed balsa/depron way (blue core is not awailable in France). The size seems to bee similar with my plans ! So I think I'll buy the plastic parts at the adress given in Your thread.
My intended B-24 is a "J" model, and will feature a rentering gear, to be able to display the lower turret (also retractable).
I just started to prepare the pieces, so You'll have to wait a few days for the first images ;-))

See You soon here !

Henry
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Old Feb 04, 2009, 07:04 AM
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Great job!

Doug

I just stumbled upon your thread today. Congrats, what a great job!
Maybe now I can be convinced to kit this one too.

Fahim
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Old Feb 04, 2009, 07:16 AM
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Roanoke Texas
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Sm

Quote:
Originally Posted by Smokin' Beaver
Wow - awesome job!
Thanks for taking the time to share that project, very inspirational indeed.
I have a little tech question if I may?
Do you recall the CG location at all?

I'm doing a scale version of the same but at only 48" span & any info would be handy.

Cheers - Phil
The CG should be about 20% of the cord at the wing root.
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Old Feb 04, 2009, 07:36 AM
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This is the way I find CG , Since I gave a Doug a hand at it on this one I thought I would chime in.
This might be too simplistic for you MIT types to get your head around so just move on or your big head might explode. I took this from a RCM article written by Chuck Cunningham many years ago and It has served me well. You cant argue with 200 models built.
A.
This is a constant chord wing mostly found on trainers and cub type models. Having a constant chord puts the Mean Aerodynamic Chord the same across the wing. (MAC)
So . . .to find CG measure the chord ( leading edge to trailing edge ) Make a mark 30 to 33 percent from the leading edge. This is your CG range and will get you close enough for your first flight.

B
This is a tapered chord wing ( Dougs wing) Since the chord changes MAC has to be found. At the root, draw two lines equal to the tips chord length. At the tip draw two lines equal to the root chord length . connect the corners to form an X . where they meet is MAC. Make a mark 30 to 33 percent from the leading edge at the MAC line. This is your CG range and will get you close enough for your first flight.

C
This is a tapered chord wing with sweep, Follow the steps found in the B wing.

D
This is where we break all the rules, Ive been told that all Delta wings have their MAC at 1/3 the length of the leading edge from the root. This holds true from the research I have done . The catch is the CG range is 22 to 24 percent of MAC.
I got some bad advice from the experts here on the E zone ( %28) and it nearly killed the B-58 article.
Ill stand behind A,B,C but D . . . .better build a chuck glider.
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Old Feb 04, 2009, 10:26 AM
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Thanks Keith

That will put you in the ball park and then you need to fine tune it from there like Keith said. I was amazed that the B-24 was just right on the first flight after the aplication of this method. And for a close to scale B-24 wing it worked out ot be about 20% of the chord at the wing root.
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Old Feb 04, 2009, 04:34 PM
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Great - thanks very much guys. very much appreciated.


Phil
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Old Feb 05, 2009, 02:36 PM
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Well Meester Doug:
I was one of the fortunate ones to be there on this recorded flight. All I can say is BEAUTIFUL and AWESOME work!!! I wouldn't expect anything less from you!
your pal, Noel
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Old Feb 25, 2009, 08:35 AM
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Noel

Quote:
Originally Posted by Cougar01
Well Meester Doug:
I was one of the fortunate ones to be there on this recorded flight. All I can say is BEAUTIFUL and AWESOME work!!! I wouldn't expect anything less from you!
your pal, Noel
Thank you for your kind words. I have not looked at this thread for a bit so glad to see people are still enjoying it.
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Old Mar 03, 2009, 04:24 PM
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Power setup

Hi Doug

can you give us some details about your power setup ? I started playing with my own Liberator project in Sketchup and when I compare size of my motors and yours it looks like I am overpowering my setup little bit.
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Old Mar 03, 2009, 08:32 PM
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Amper

Its all back in the thread around number 3
Quote:
Originally Posted by Amper_CZ
Hi Doug

can you give us some details about your power setup ? I started playing with my own Liberator project in Sketchup and when I compare size of my motors and yours it looks like I am overpowering my setup little bit.
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Old Mar 03, 2009, 10:07 PM
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Quote:
Originally Posted by Douglas C
The CG should be about 20% of the cord at the wing root.
Thanks Doug & Keith.
20% was the perfect CG point. It flies well, with no pitching issues at all.
This is the Guillow's kit, basically straight out of the box.
So it's scale proportions and flying well on 80W per pound.
(120W @ WOT, 24 oz AUFW)

http://www.vimeo.com/3416740

Thanks again chaps - Phil
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Old Mar 04, 2009, 01:25 AM
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Quote:
Originally Posted by Douglas C
Its all back in the thread around number 3
there is just "I used for inexpensive Tower Pro motors from Grayson" :-) I hoped in more detailed info - type of motor, propeller dia and if you have measured then input watts it will really help me.
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