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Joined: 5/25/2004 From: _ , USA Status: offline
Years ago there was a 60 size 650 sq in pattern aircraft design called the “Cold Duck”. It was very sleek, super light (six pounds with retracts) and fast! And that was six pounds loaded down with old heavy PCS radio gear and giant KPS9 servos. I built one in 1969 and really liked it but it met its end in a mid air with a Kaos in the early 70s. After all these years I decided it was time to build another and I still have my plans from the June 1971 RC Modeler Magazine. The original design was a tail dragger with main gear retracts because in 69 retracts were a pretty risky proposition and two of them was more than enough trouble. The new “Cold Duck” will have trike gear! My original was powered by an old Veco 61 but the new one will have a powerful and modern 61.
Some images of the original circa 1970.
< Message edited by 8178 -- 6/23/2005 10:21:59 PM >
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Builder and flyer of high performance acrobatic R/C aircraft and a proud member of VR/CS. Made in China = no sale!
Posts: 3017
Joined: 5/25/2004 From: _ , USA Status: offline
I’ve ordered the balsa needed to build the Cold Duck from Dynamic Balsa ( http://www.dbalsa.com/ ) and also the foam wing core. Everything was in stock so I should have the order in a few days. Meanwhile, I started building the horizontal and vertical stab. I’m using my vintage, tattered and yellowed RCM plans but new Cold Duck plans are still available from the RC Modeler Magazine plan service at http://www.rcmmagazine.com/e/env/00014INjeTp9LDIock0y6w8/index.html?link=store/store-plans.html plan number 462.
The horizontal stab is built typical of the “Classics” using a ¼ balsa frame and covered with 1/16 balsa sheeting. I’m using the very lightest balsa available.
View of the old plans and the horizontal stab progress.
< Message edited by 8178 -- 6/28/2005 8:27:59 PM >
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Builder and flyer of high performance acrobatic R/C aircraft and a proud member of VR/CS. Made in China = no sale!
Posts: 3017
Joined: 5/25/2004 From: _ , USA Status: offline
View of the tail parts with the bass wood trailing edges installed and more shaping work completed. The elevators and rudder have been tapered down to the 1/8” X 1/16” trailing edge.
The original Cold Duck had ailerons that were added to the wing trailing edge similar to the way the Kaos ailerons were designed. The new Cold Duck will have ailerons that are a continuation of the airfoil shape like my Howard Engineering Kwik Fli III taper wing has. To that end, I ordered a set of Howard Engineering Kwik Fli III taper wing ailerons and they can be seen at the top of the image. They are 1 ½” wide and will have 1/8” X1/16” bass wood trailing edge added. I should have my Dynamic Balsa shipment soon with my balsa and foam wing core.
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Builder and flyer of high performance acrobatic R/C aircraft and a proud member of VR/CS. Made in China = no sale!
Posts: 3017
Joined: 5/25/2004 From: _ , USA Status: offline
View of the nose ring, Dave Brown (50-60) engine mount, fire wall, fuselage formers, and front former doubler. The wing will have a ¼” plywood tongue that will fit into the square opening in the front fuselage former like is used on the Howard Engineering kits. I’m moving the firewall back ½” to make more room for the longer engine. The old Veco 61 that the Cold Duck was designed around was pretty short.
My Dynamic Balsa order shipped last Friday so it should arrive next week with my balsa supply and foam wing core. I also ordered a canopy, aileron linkage, Dave Brown Southern Sorghum foam wing glue and a Goldberg 2” white spinner from Tower. The 10 ¼’ Great Planes canopy is shorter than what I wanted but canopy choices are pretty limited now-a-days.
_____________________________
Builder and flyer of high performance acrobatic R/C aircraft and a proud member of VR/CS. Made in China = no sale!
Posts: 3017
Joined: 5/25/2004 From: _ , USA Status: offline
I like to complete the setup of the engine mount, fuel tank and nose gear steering before the firewall is installed. It is a lot easer to drill holes and mount stuff with the firewall on the bench. Many years of building Howard Engineering kits has influenced the way I build, so I’ll be borrowing his well engineered fuel tank mounting system for the Cold Duck. See my Howard Engineering Kwik Fli III build on RCU at http://www.rcuniverse.com/forum/m_2434444/tm.htm
A plywood plate is made for the front of the fuel tank that bolts to the firewall with blind nuts. It is a really neat system and keeps the fuel lines from getting kinked and makes tank installation and removal easy. I’m using the specified Sullivan RST-12 fuel tank.
I decided to mount the engine less than the original 90 degrees for a little more muffler clearance.
< Message edited by 8178 -- 6/26/2005 4:58:13 PM >
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Builder and flyer of high performance acrobatic R/C aircraft and a proud member of VR/CS. Made in China = no sale!
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Cold Duck - Build - 
