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Building Tips and technical articles. => 1/2 A building. => Topic started by: Larry Lindburg on January 05, 2012, 09:58:33 PM

Title: Deweybirds: the Final Chapter
Post by: Larry Lindburg on January 05, 2012, 09:58:33 PM
Though I prefer OK Cubs, Testors, and Coxes, I decided to use something different on my final Deweybird.   Since I use 42 foot lines with the Coxes, I might try 45's on this one.
Title: Re: Deweybirds: the Final Chapter
Post by: Larry Renger on January 05, 2012, 11:08:26 PM
Hmmm, with that tank it'll be a short flight, but a merry one!   LL~
Title: Re: Deweybirds: the Final Chapter
Post by: minnesotamodeler on January 06, 2012, 08:27:13 AM
45's will be none too long, depending on how fast you want to spin.  Power of that .061 will amaze you.
Title: Re: Deweybirds: the Final Chapter
Post by: Larry Lindburg on January 06, 2012, 08:44:42 AM
The engine is a Big Mig .049, and the tank is two-thirds of an ounce.  I'll use 15% Sig Champion fuel.  Prop is 5.5-2 APC spinning 18000-19000 rpm.  Anyone have an idea of the duration with this?
Title: Re: Deweybirds: the Final Chapter
Post by: john e. holliday on January 06, 2012, 09:05:42 AM
With that tank sitting that far from the engine and to the outside, it looks like you may have to set a little rich on the ground.   Anyway I like the looks of the plane. H^^
Title: Re: Deweybirds: the Final Chapter
Post by: fred krueger on January 06, 2012, 11:28:49 AM
Sweeeet!

You might try 42' lines.  I'm flying my 150 Ringmaster (also .049 Big Mig powered) on 42' with 5x3 APC prop.  I tried the 5.5x2 and liked the 5x3 a touch better.

It will move out briskly!  You should make the Beginner pattern, maybe close to the whole pattern.  3/4 oz. on 25% gives me time for the whole pattern.

Fred
Title: Re: Deweybirds: the Final Chapter
Post by: wwwarbird on January 06, 2012, 09:58:29 PM
 Neato Larry! y1
Title: Re: Deweybirds: the Final Chapter
Post by: louie klein on January 07, 2012, 07:54:05 AM
Larry, nice job! I wish we could get those fuel filters again.--LOUIE  H^^ H^^ D>K
Title: Re: Deweybirds: the Final Chapter
Post by: Larry Lindburg on January 07, 2012, 06:45:31 PM
That is a Dub Jett filter.  It is the narrowest filter I have seen.  It is still available according to the Jett Engineering  website.
Title: Re: Deweybirds: the Final Chapter
Post by: minnesotamodeler on January 08, 2012, 06:36:48 AM
The engine is a Big Mig .049...


Huh...must be quite a variation on these things.  Every one of my .049s have "silvery"cooling fins MOL the same dia. as the crankcase...all but one of my .061s have the dark-anodized oversize fins per your engine; the one exception uses the smaller fins (as does my AP Wasp)--so I know some .061s use the smaller fins, but I had never seen an .049 with the larger fins.  Live and learn.   
Title: Re: Deweybirds: the Final Chapter
Post by: George on January 09, 2012, 06:38:21 PM
The "silvery" ones were the earlier nickel plated ones. The later ones are the aluminum oxide anodized "Revlite" ones. If I remember correctly, Big Migs (.049 and .061) came in Revlite but I THINK the AME's did not.

George
Title: Re: Deweybirds: the Final Chapter
Post by: Larry Lindburg on January 09, 2012, 09:07:46 PM
By the way those dark colored fins seem not to conduct electrical current to that little Merlin head.
Title: Re: Deweybirds: the Final Chapter
Post by: John Rist on January 10, 2012, 09:07:48 AM
By the way those dark colored fins seem not to conduct electrical current to that little Merlin head.

The black fins are probably black anodize aluminum.  Anodizing does not conduct electricity.
Title: Re: Deweybirds: the Final Chapter
Post by: minnesotamodeler on January 10, 2012, 04:22:40 PM
This is true.  Save a lot of frustration, ya hafta make contact with the head itself.

I wonder how many people with Kwik Klips have branded them "unstartable"?!?!?!
Title: Re: Deweybirds: the Final Chapter
Post by: Bill Adair on January 10, 2012, 05:26:31 PM
I have a NIB Norvel .049 with AME porting, and a Revlite cylinder! It's the only one I've ever seen.

Bill
Title: Re: Deweybirds: the Final Chapter
Post by: wwwarbird on January 10, 2012, 08:27:46 PM
 Would the dark part be titanium?
Title: Re: Deweybirds: the Final Chapter
Post by: Larry Renger on January 11, 2012, 10:57:46 AM
No, the dark part is "hard anodized" Aluminum.  I don't know what makes some anodizing harder than others, perhaps someone will enlighten us.
Title: Re: Deweybirds: the Final Chapter
Post by: wwwarbird on January 11, 2012, 07:09:55 PM
 Didn't really think so, just thought maybe.
Title: Re: Deweybirds: the Final Chapter
Post by: John Rist on January 11, 2012, 07:45:23 PM
More info on Anodizing

http://www.electrohio.com/Finishing/AlAnodizing/AlAnodizing.htm
Title: Re: Deweybirds: the Final Chapter
Post by: George on January 13, 2012, 06:09:09 PM
No, the dark part is "hard anodized" Aluminum.  I don't know what makes some anodizing harder than others, perhaps someone will enlighten us.

If I understand correctly, hard anodizing actually fuses the aluminum oxide with the aluminum. It is not just a coating.

George
Title: Re: Deweybirds: the Final Chapter
Post by: GGeezer on January 14, 2012, 05:24:20 PM
The only difference between regular type II (less than .001") anodizing and Type III hardcoat is the thickness of the oxide layer. Special process controls are needed to produce coatings between .001" and .005" (type III).

Orv.