SMALL - SMALL - Telemetry SMALL - Radio
Thread Tools
Old Dec 14, 2014, 04:15 PM
Now I have to land that thing?
PGregory's Avatar
United States, NY, Poughkeepsie
Joined Apr 2014
202 Posts
Build Log
Ken Willards MAN Aug 1953 "Duranita" for AMPLAN Build Off

To pick an AMPLAN design... Not so easy...

As SteveWMD knows I have become a big fan of his site this year. What a gem once I found it - I think I spend at least an hour a day on there, sometimes many more. One thing it has helped with is a sense of history, but of continuation. I got to know more about Designers across the board like Walt Musciano for all his scale designs, Lou Andrews for some still-relevant classics, Hal de Bolt & John Coasby for C/L that are still competing in OTS. Of course giving homage to our model flying heritage is never complete. However, as electric foamies repiqued my interest in model airplanes this year, and the call of glow fuel then rekindled, through tramping in, around and through Outerzone I became familiar with the name Ken Willard. His designs were on the top of my list because most had a non-serious nuance about them, were great flyers, and were not that complicated - if you really haul you could finish on in a week, if really determined.

So over time, coming in from out of the internet fog and into my consciousness were these threads I started noticing once in a while, the RCGroups Vintage and Old-Timers Designs build-off's. I didn't catch what these were all about at first but things gelled over time and then I understood there was this active AMPLAN build going on - with 7 out of the 25 builders already having built and flown already (some having sold and lost so I understand). I have some building to get on to.

I just picked up a Scientific Mercury kit from the 1940's and thought I might use that - but I see P_J_Glor has that one earmarked and since he and I share the same three initials I thought that would get confusing - ha...

So, I spent a little time getting my bearings on Outerzone yesterday, Saturday, about finding a US publications plan before 1965. One of Ken Willard's designs that I hadn't noticed before kind of jumped off the page for me - the 1953 Duranita FF, at 43" WS and designed light to take a .8cc diesel. It hasn't been covered that much, either.

in addition, I have a horde of engines I have to find homes for from a little CO2 up to size .40's - things I picked up here on RCGroups and some from eBay. It is just a matter of picking one out of a good list.

The Duranita Specs
As Is - 43 inch Wingspan, main wing
Biplane - Gull Wing top wing, simple shortened version of same design as low wing.
Side panels of 3/32 balsa with significant lightening holes.
1/4 balsa vertical and cross braces
Pretty simple 1/16 top and bottom sheeting
Designed for .049 or so diesel, I have multiple options in this category

The trickiest part at the outset is converting the tailfeathers from solid 3/32 sheet balsa vertical stab, and one-piece horizontal built-up horizontal stab, to adding a rudder and split elevators. That doesn't look so bad. I am wondering about the fact the horz stab has an airoil, though - it offers lift at the rear of the airplane. Unless I see something that steers me in a different direction, I am just going to keep the airfoil. Wing incidence I will keep as designed for the FF model - it looks like 0 incidence lower wing and maybe +3 degrees on the upper. That provides decent stall characteristics, I believe.

Oh, and I will scale the plane up a bit by 1.15% to take it to nearly 50 inch wingspan. Possibly, I may have to had webbing or trusses where the two breaks in the main wing occur. We'll cross that bridge when we come to it.

I ran up my materials list, now headed over to get prints made at my local Staples, and soon will start cutting wing ribs, etc.

Cheers -
Poughkeepsie Pete
PGregory is online now Find More Posts by PGregory
Reply With Quote
Sign up now
to remove ads between posts
Old Dec 14, 2014, 08:49 PM
The dog ate my clearance
brokenspar's Avatar
Joined Jan 2004
1,096 Posts
That's a pretty design with the novelty of a gull-wing biplane. Good luck on the build, and we'll be watching.
brokenspar is offline Find More Posts by brokenspar
Reply With Quote
Old Dec 14, 2014, 10:47 PM
Now I have to land that thing?
PGregory's Avatar
United States, NY, Poughkeepsie
Joined Apr 2014
202 Posts
Thanks brokenspar. As I am getting into the plan I am seeing the mods to the tailfeathers are straightforward as compared to a couple other things that seem to be more of "suggestions" than hard design.

So, I ordered up a copy of the August 1953 MAN I happily found on eBay today, to get the article and any notes about the build. I will scan the article and post, and send to SteveWMD at outerzone, too.

This design was built light to be powered by an 049 Diesel (McCoy Dura Glow), The wing loading is going to go up and I can see I am going to be looking through my engines for something more - maybe a Norvel .074 RC. I have to see if I have an RC diesel that might go well.

PGregory is online now Find More Posts by PGregory
Reply With Quote
Old Dec 14, 2014, 11:26 PM
Registered User
harborflyer's Avatar
United States, CA, Santa Ana
Joined Jul 2010
480 Posts

harborflyer is offline Find More Posts by harborflyer
Reply With Quote
Old Dec 15, 2014, 03:36 AM
I like real wooden aeroplanes!
Sundancer's Avatar
South-west France
Joined Sep 2007
5,006 Posts
Looking forward to watching this one take shape - I am a confirmed biplane groupie! I've posted your build og link to post#1 of the build off thread.
Sundancer is offline Find More Posts by Sundancer
Reply With Quote
Old Dec 15, 2014, 11:48 AM
I'd rather be flying.....
United States, IA, Story City
Joined Oct 2013
535 Posts
Nice choice !

Best Regards,

JeffMac is offline Find More Posts by JeffMac
RCG Plus Member
Latest blog entry: Willie Smith " TORERO " ...
Reply With Quote
Old Dec 15, 2014, 12:00 PM
Registered User
Paul_BB's Avatar
France, IdF, Lagny-sur-Marne
Joined Feb 2007
512 Posts
Good luck!

Paul_BB is offline Find More Posts by Paul_BB
Reply With Quote
Old Dec 16, 2014, 07:38 PM
Registered User
Canada, ON, Hamilton
Joined Oct 2005
2,747 Posts
Nice choice of models PG. I'm thinking that the gull wing is more of a challenge than rudder /elevator choices. As an after thought, since you are scaling the plans up, you might want to consider additional ribs in order to keep them from getting too far apart.
(just my 2cents worth).
JohnAV8R is online now Find More Posts by JohnAV8R
Reply With Quote
Old Dec 16, 2014, 08:46 PM
Now I have to land that thing?
PGregory's Avatar
United States, NY, Poughkeepsie
Joined Apr 2014
202 Posts
Yes, thanks for the comments, everybody...

The upper wing is going to need another spar - maybe even a third toward the trailing edge, to keep the wing from torquing, being that each wing is freestanding - i.e. no supports between them. The breaks in the upper wing that give make the gullwing are going to need to be reinforced - I see that coming. I will probably put webbing between an upper and lower spar.

Cheers - Peter G.
PGregory is online now Find More Posts by PGregory
Reply With Quote

Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Build Log Miss Philadelphia V (75%) for AMPLAN Build off RFJ Vintage & Old-Timer Designs 78 Today 09:34 AM
Build Log Hummingbird for AMPLAN Build Off Sundancer Vintage & Old-Timer Designs 36 Yesterday 05:33 PM
Build Log Keith Laumer's Push-Up for AMPLAN Build Off brokenspar Vintage & Old-Timer Designs 48 Dec 20, 2014 04:07 AM
Build Log Fred Dunn 75% Astro Hog for AMPLAN Build Off RFJ Vintage & Old-Timer Designs 72 Nov 26, 2014 05:42 AM
Build Log Bill Winter's "Airknocker" for AMPLAN Build Off - finished and flown Sundancer Vintage & Old-Timer Designs 107 Nov 19, 2014 06:26 PM