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Old Apr 14, 2006, 11:57 AM
Too little play time...
WarrrEagle!'s Avatar
South Alabama
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Advice needed on a scratch built profile foamie P-47.

Gents I need some advice and some input.

I want to build a profile Thunderbolt... I projected a 3-view onto poster paper with a PC projector and have now cut out the templates. I enlarged the wing and the stab/tail feathers a bit.

As cut the length is 23.5", the wingspan 31" and the stabilizer 12.5" wide.

Power will be a Esskay 400XT or a BP-21 with a firewall mount in all likelihood.

A photo is attached...

Do these dimensions look OK to y'all? Basically, WILL IT FLY?!

I plan to mount the wing a tad higher than the 3-view showed for stability. I am also considering narrowing the nose a tad. I overlaid another 3-view I found and it came in a bit narrower at the nose and at the vertical stab/rudder. You can possibly see the alternate pencil lines in those spots.

I don't know if I am going to go A/E/T or full house on the controls yet.

I am debating one of three construction techniques; one ply fuse with a spar like the Nasty, two ply fuse with a spar like the STC or shocked.

I am leaning towards one ply with spar as the Nasty has proven sturdy and this won't be tossed around like a 3Der. Plus it will be shorter so there should be less flex involved. Y'all concur?

I am uncertain as to how to cut the ailerons on this one. I assume they need to extend far out on the wing, right?

I am also debating as to a flat or under chambered wing...

If this one works out well my brothers and I are gonna crank out several types for combat. We would like it to be a scale like as possible so smaller surfaces and low throws will be the order of the day.

I'll also post a couple of pics of what served as the inspiration and possibly a paint guide if I go that route.

Thanks in advance for ANY input!

(Too many "I's" in this post, eh?)
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Old Apr 14, 2006, 12:34 PM
Crash Master
Gene Bond's Avatar
Indianapolis, IN
Joined Sep 2001
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Increase the V-tail area (15-20% of wing area), and you should be fine... It's a little small IMO... All else is personal choice! Plenty of pro's and con's on all points
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Old Apr 14, 2006, 01:05 PM
Too little play time...
WarrrEagle!'s Avatar
South Alabama
Joined Feb 2005
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If it is smallish I guess I should try to go the light route? One ply and maybe just A/E/T?

Increase the vert stab maybe 1/2" in front and top? Would that do it?

I guess the small size will make it just fly a bit hotter?

How about the ailerons? Which of these cuts would you suggest?

Thank you.
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Old Apr 14, 2006, 01:15 PM
Registered User
Dallas Texas
Joined Oct 2004
917 Posts
That's great, I am in the process of decorating a P-47 made from doubled Paul Bradley plans found here http://www.parmodels.com/Plans/nocals.htm
Mine is set up for rudder/elevator controll with undercambered wings like the plan shows, and about 15 degrees dihedral. Let us know how yours goes. I won't be able to install gear in mine untill I retire another plane, and its been too windy to fly much lately, so nothing is getting worn out.

Good Luck on the Jug
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Old Apr 14, 2006, 01:20 PM
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Dallas Texas
Joined Oct 2004
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Quote:
Originally Posted by WarrrEagle!
If it is smallish I guess I should try to go the light route? One ply and maybe just A/E/T?

Increase the vert stab maybe 1/2" in front and top? Would that do it?

I guess the small size will make it just fly a bit hotter?

How about the ailerons? Which of these cuts would you suggest?

Thank you.
On my flat wing combat planes, I have the best luck with something like your blue outline, but I would extend it out to the wing tip.
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Old Apr 14, 2006, 01:41 PM
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Joined Nov 2004
857 Posts
The thing to watch for with tapered edge ailerons is the adverse yaw created by the differential leverage at different points along the span of the aileron. That said, the red-line cut will slaughter your roll rate. Do the blue cut, as is, it doesn't need to go out to the tip and that cut offers a little better stiffness against aileron/wing flex and some ground loop protection.

My $.02

Ho
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Old Apr 14, 2006, 07:11 PM
Too little play time...
WarrrEagle!'s Avatar
South Alabama
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Thanks for the input so far...

Any other tips? I would really like this to be a success.
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Old Apr 14, 2006, 07:26 PM
Foam rules
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HdG Md.
Joined Jan 2003
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Yep do the red line for the ailerons and add to the tail like Gene said and it should be fine. I've built a few profile P-47's and they all needed way bigger verticals as the nose is so huge which make them handle horrid with stock vertical. In fact I'd go as big as I could to the point of looking stupid and cut it back little by little as flight test prove the design. I always start off to small and add.
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Old Apr 14, 2006, 09:35 PM
Crash Master
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Indianapolis, IN
Joined Sep 2001
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Yes, what TOG said about the vertical.. without more vertical, the adverse yaw will kill you. I think those are 1" squares on the grid... 1" all the way around looks good to me!
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Old Apr 15, 2006, 09:32 AM
Too little play time...
WarrrEagle!'s Avatar
South Alabama
Joined Feb 2005
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Thanks, Gentlemen.

I'll be cutting today!

Gonna go one ply with a spar and a flat wing.

I guess I will make the first one quick and dirty and after seeing how it goes I may make a keeper to paint up...
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Old Apr 15, 2006, 03:14 PM
International flyer
France, Alsace, Wissembourg
Joined Jul 2005
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Lots of power for your work. Don't worry your plane will fly good

First plane i made by my own (a F4U Corsair, i posted a thread about it) flew really good and it was a great surprise and also a great pleasure for me

Have fun.

TeX
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Old Apr 16, 2006, 10:34 PM
Victoria Super Mortem
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BIRMINGHAM ALABAMA
Joined Jan 2006
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I am currently finishing the E-Flight ARF P-47. Yeah I broke down and bought a scale kit, but it is totally made of Foam. The model has 1 servo for each aileron and they most closely resemble the blue line, but they dont begin until about 1/2 way out the wing. I 'll take a pic and post it asap. Otherwise, sounds like you got a winner. Check out the cartoon scal P-47 from Foam Fly.com I built one of those and it is a blast.

Bo
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Old Apr 16, 2006, 10:41 PM
Too little play time...
WarrrEagle!'s Avatar
South Alabama
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I would like to see a pic of that UBI...

No cutting done yet. Easter Bunny and all ya know?!
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Old Apr 16, 2006, 11:00 PM
Victoria Super Mortem
UBILDIT's Avatar
BIRMINGHAM ALABAMA
Joined Jan 2006
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Picture

Hope the bunny was good to the linebacker and the cheerleader. I know we'
re talking about 2 different animals here, but I flew one of these that a friend had put together and just had to do one. The scale look is great. It is powered b y a 450 outrunner and is A/E/T. The only reason I was thinking about adding Rudder would be for steering on the ground. One of the easiest builds I've ever done as well. Pictured with APC 1043 prop, trying to modify the stock prop which is 1080. No other specs on it right now, but almost finished. Maybe these will help. Let us all know how it goes. sounds like a fun combat plane. I think you're on the right track with the Nasty Basics for rigidity. Recently noticed some of my club buddies with what looked like the Nasty, but they had a flat piece of CF about as wide as the FFF is thick hot glued to the LE instead of in the wing. Then they had triangle balsa running the length of the fuse with no shocks on either side. It was super light and super manueverable. Of course it was designed for 3D, but take a little good engineering here and there and put it to work for you however you need it right??
Good Luck..

Bo
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Old Apr 16, 2006, 11:09 PM
Too little play time...
WarrrEagle!'s Avatar
South Alabama
Joined Feb 2005
1,500 Posts
The kid-os are great and had a great day with family! Thanks for asking!

I like that E-Flite... Well made model from what I've seen and heard. If it was a silver bubble canopy version like their .60 sized gasser I'd be on it in an instant. I just don't like the razorback as much...

I wonder if I should consider using two servos for the ailerons? Maybe if the plane was going to be bigger... I think I need to build light due to the small size.

I guess that lovely couple trial and error will be my assistants on this project!

Thanks for the pics!
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