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Building Tips and technical articles. => 1/2 A building. => Topic started by: john vlna on January 26, 2012, 11:04:49 AM

Title: An Original Skyfire
Post by: john vlna on January 26, 2012, 11:04:49 AM
Way back in April 1975, Larry Renger published a 1/2A model around COX foam wings in Flying Models. These are thin foam wings that were made for the Super Stunter and Super Chipmunk. While rummaging through my stuff I found a pair of these wings and decided to build a Skyfire. I am making two changes to the design; using electric vice glow power and changing to two wheels vice the original one wheel gear. This will make it easier to stooge. Plans are still available from Flying Models(CF-368), but the wings of course are not. All wood or foam wings could be substituted and it is a neat looking model.
Title: Re: An Original Skyfire
Post by: Larry Renger on January 28, 2012, 04:09:13 AM
Way cool!  Let us know what electric equipment you select, the flying weight, and how it all works out.  #^
Title: Re: An Original Skyfire
Post by: john vlna on January 28, 2012, 05:57:21 PM
Larry,

I don’t have a final weight yet. I am shooting for an all up weight of 7.5oz. The plane without paint is a bit under 4oz. I’ll use one of these motors. I have used both on 1/2A size models before.
Turnigy 2730-1700 http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=8619

AX 2306-2000 http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=5428

Battery will be a 500mah, 25c 3s
Esc 12A
E-Flite or Brodak timer.
 It is a great design and went together very easy. I wish these wings were still around. I've used them before to build a 15 carrier plane. I put more structure in the wing since carrier models take a beating.
Title: Re: An Original Skyfire
Post by: john vlna on January 28, 2012, 06:51:47 PM
Here are a couple of pictures of the Skyfire and XFL, same wing but the xfl has bigger tips and a bit of a flap. The xfl fuselage is a bit larger also.
Title: Re: An Original Skyfire
Post by: Larry Renger on January 29, 2012, 02:02:58 AM
Lookin' good!  y1

On mine, the rudder is straight, but the sub rudder is canted.  That puts the deflected part directly in the propwash. No rolling moment due to rudder!
Title: Re: An Original Skyfire
Post by: john vlna on January 29, 2012, 12:40:36 PM
Larry
Are you talking about the MK2 Version? My plan does not have a sub rudder. Interesting idea though.
John
Title: Re: An Original Skyfire
Post by: Larry Renger on January 29, 2012, 07:47:02 PM
I lose track!  I'm up to about version 5 or 6. I guess only the later ones had a sub-rudder.  It seems effective set up that way.
Title: Re: An Original Skyfire
Post by: john vlna on April 15, 2012, 06:47:17 PM
I finally got out to fly the Skyfire today and it really flies great.
I went with the Turnigy 2730-1700, APC 5.5x4.5E, 12A ESC, 500mah 3s1p 20c battery, Brodak Timer, 42' spectra lines
It is fully stuntable, and can do the full pattern, it is definitely a keeper.  I'll post some weight details and pictures tomorrow.
Title: Re: An Original Skyfire
Post by: jim gilmore on April 15, 2012, 10:46:51 PM
photo with electric ?
Title: Re: An Original Skyfire
Post by: Larry Renger on April 16, 2012, 08:37:19 AM
Congratulations!  I look forward to the photos.   H^^
Title: Re: An Original Skyfire
Post by: john vlna on April 16, 2012, 02:12:54 PM
The flying weight is 7.8oz. I made two changes from the original plane. The leadouts and the tip weight are adjustable. Initial flight showed the tip weight to be right on. I will probably cover that up when I paint it. I am not exactly sure what I am going to do for the finish, but I don't want to add much weight. With the 500mah battery I am getting 3.5-4 minute flights. Also I'll dress up the wires a bit, shorten, etc. That will also save a bit of weight.
Title: Re: An Original Skyfire
Post by: Larry Renger on April 17, 2012, 10:32:53 AM
Nice!  And isn't it great that you can test fly BEFORE finishing? 
Title: Re: An Original Skyfire
Post by: john e. holliday on April 17, 2012, 12:24:14 PM
I would just outline the canopy and AMA numbers.   But, I go for simple paint schemes, unlike some people I know. LL~ LL~

Forgot to say it looks great.
Title: Re: An Original Skyfire
Post by: john vlna on April 17, 2012, 07:25:38 PM
Well Doc, it will be simple, and I don't want to add much weight. It flies so well as is. And Larry, yes it is nice to make sure it flies before finishing. I've spent to much time finishing a plane and then being disappointed in performance.
Title: Re: An Original Skyfire
Post by: Larry Renger on April 18, 2012, 09:35:45 AM
The original was a solid color on the fuselage and tail, and the deco. was all trim Moneykote.  I thought it looked pretty cool.
Title: Re: An Original Skyfire
Post by: ray copeland on April 18, 2012, 09:57:39 AM
Neat project John!!  I did one similar with a Hyper Viper wing and a norvel.