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Old Mar 25, 2015, 07:46 PM
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fly like an EAGLE ;)
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btw im working on a large f15 for twin edf should have it ready way before az jets if you make it this year..
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Old Mar 25, 2015, 10:54 PM
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Originally Posted by corsair nut View Post
btw im working on a large f15 for twin edf should have it ready way before az jets if you make it this year..
Heck yeh I'll be there! I need the face time with Larry to give him a ration!
('scuse me while I go drool.....'15's!!!! )
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Old Mar 25, 2015, 11:04 PM
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fly like an EAGLE ;)
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tehachapi, CA
Joined Jan 2006
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highly modded byron...scale gear..full gear doors...full ducting..no cheater holes..and re shaped inlets and stab tips. its not perfect scale but a whole lot better

yes...its sitting a little high.need to dial in the stance a bit
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Old Mar 26, 2015, 05:35 AM
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Hey Guys, Watch This.......
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USA, TX, El Paso
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Nice!

Mike
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Old Mar 27, 2015, 05:47 PM
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Capt. Z
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Originally Posted by rvincent View Post
Where's Andy? Haven't seen him in any threasds for quite a while?
I still come sniffing around the R/C airplane sites once and while. My A-4 still fly's great but she hasn't got much attention lately..busy doing other stuff.
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Old Mar 27, 2015, 06:34 PM
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Renegade Fun Forever!!
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Good to hear from you!
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Old Mar 27, 2015, 10:31 PM
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I still come sniffing around the R/C airplane sites once and while. My A-4 still fly's great but she hasn't got much attention lately..busy doing other stuff.
Good to hear from you...Miss watching your mega builds...
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Old Mar 28, 2015, 05:48 PM
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Clear Skies & Contrails
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Edwards AFB, CA
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Andy,

Great to see you lurking around RCG!

See you in 7 months!

Best,
Tony
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Old Apr 21, 2015, 12:55 PM
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Off topic but didn't want to start a thread for a video.

Snowbirds TankCam (4 min 40 sec)
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Old Apr 27, 2015, 07:03 PM
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Questions regarding 88" A-4 Skyhawk

This 88" long A-4 is a very impressive EDF!

I plan to build a 90mm EDF version and have a few questions that I hope someone such as Falcon5 or A10pilot can answer.

Are the overall shape and the wing/fuse/horizontal stab proportions based on the Bell Models A-4 plan? If so, were any changes made?

Was the flat bottom airfoil shown on the Bell plans used or was it modified?

Did anyone build washout into the tips or is washout not necessary on this model?

Was the bottom of the leading edge rounded at all?

Where is the center of gravity on the wing? (I couldn't see it on the Bell plans).

I assume the top of the wing is completely flat/straight (front view) per the real A-4?

I have seen a few suggestions regarding wing and horizontal stab incidence. If the bottom of the wing is 0 degrees and the stab has approximately 1 degree of "up", would that work? This is what I have done on past scratch-built models.

Thanks in advance!

Cheers!

Mike
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Old Apr 27, 2015, 08:48 PM
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Quote:
Originally Posted by Viper1957 View Post
This 88" long A-4 is a very impressive EDF!

I plan to build a 90mm EDF version and have a few questions that I hope someone such as Falcon5 or A10pilot can answer.

Are the overall shape and the wing/fuse/horizontal stab proportions based on the Bell Models A-4 plan? If so, were any changes made?

Was the flat bottom airfoil shown on the Bell plans used or was it modified?

Did anyone build washout into the tips or is washout not necessary on this model?

Was the bottom of the leading edge rounded at all?

Where is the center of gravity on the wing? (I couldn't see it on the Bell plans).

I assume the top of the wing is completely flat/straight (front view) per the real A-4?

I have seen a few suggestions regarding wing and horizontal stab incidence. If the bottom of the wing is 0 degrees and the stab has approximately 1 degree of "up", would that work? This is what I have done on past scratch-built models.

Thanks in advance!

Cheers!

Mike
Mike:
I don't recall all of the answers to all of your questions above but I will try to answer some.

1. I did use the John Bell plans blown up to the appropriate size.
2. I did use the wing profiles on the Bell plans. I used the flat bottom airfoil and about 1 deg. of washout. My plane flew very well and landed very nicely without flaps.
3. The leading edge was rounded but flat on the bottom to conform/meet the flat bottom airfoil.
4. I do not recall the CG location but mine (and I believe Andy's (falcon5) were posted in the thread.
5. Top of the wing as flat.
6. Incidence was: Wing at +1 deg. positive (leading edge up) and the stab was at zero deg. with the wing at +1.

I will see if I can find the CG.

Ed
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Old Apr 27, 2015, 09:23 PM
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Questions regarding 88" A-4 Skyhawk

Thanks for the info, Ed!

I recall reading that you cut your wing halves in 3 sections. Did you add washout only to the outboard section? It's too bad that washout is necessary because foam cutting is a whole lot easier if you can leave the bottom perfectly flat and only cut the top of the wing! Do you know if Andy used washout? I believe he hand sanded the wing's airfoil shape.

I also read that Andy moved his c of g back a few times so I'm not sure where the "sweet spot" ended up.

Thanks again!

Mike
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Old Apr 30, 2015, 08:21 PM
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deltas are cool
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nice vid EW good to see you in here
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Old Apr 30, 2015, 09:13 PM
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Quote:
Originally Posted by Viper1957 View Post
Thanks for the info, Ed!

I recall reading that you cut your wing halves in 3 sections. Did you add washout only to the outboard section? It's too bad that washout is necessary because foam cutting is a whole lot easier if you can leave the bottom perfectly flat and only cut the top of the wing! Do you know if Andy used washout? I believe he hand sanded the wing's airfoil shape.

I also read that Andy moved his c of g back a few times so I'm not sure where the "sweet spot" ended up.

Thanks again!

Mike
Mike:
I cut the wing in four sections. Center section out to just past the gear, and then from there to the tip. As I recall, I just drew the washout on the wing from the center line of the wing out to the tip and then cut each of the four sections individually. I can not find any of my notes on the location of the CG but it was what Andy ended up as he flew his before I did so I just took his CG location.

Ed
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Old May 01, 2015, 12:10 AM
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Thanks Ed! I think I now have all the information I need.

Cheers!

Mike
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