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RE: Cold Duck - Build - 2/25/2006 5:52:34 PM   
8178



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Joined: 5/25/2004
From: _ , USA
Status: offline 		That is a very good point and I usually do that. The other challenge is the person taking the video is seldom accustom to using my DV cam! On my Cannon Elura DV cam the mode of the camera must first be changed, then manual focus set and then the focus adjusted and readjusted if zoom is used.

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       Post #: 201

RE: Cold Duck - Build - 2/26/2006 12:03:56 AM   
Jim_Purcha



Posts: 994
Joined: 9/18/2003
From: La Salle, MB, CANADA
Status: offline 		In Gimli, Manitoba, they produced "Gimli Goose".

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       Post #: 202

RE: Cold Duck - Build - 2/26/2006 4:40:09 AM   
rainedave



Posts: 5011
Joined: 7/21/2005
From: Greensboro, NC, USA
Status: offline 		8178, the very first time I ever got intoxicated (and sick) was on Cold Duck! I would have been around 14, I guess. As I remember it came in little bottles in a beer-like cardboard sixpack carton. Man, the image of that purple snow in the back yard has stayed with me all these years.

Back to the thread. The model looks even better in the air. That is a cool photo where the gear isn't visible.

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       Post #: 203

RE: Cold Duck - Build - 2/26/2006 4:20:19 PM   
8178



Posts: 2941
Joined: 5/25/2004
From: _ , USA
Status: offline 		I expect everyone learned their limits at a young age, fortunately it was Rum for me and to this day it’s not something I miss. But the killer thing about Cold Duck wine is that it looked good, seemed innocent and tasted way too good and caught many off guard! Thus the name “Cold Duck” seemed appropriate for this sleek innocent looking aircraft.

Yes, I sure would have been cooler with the retracts. Maybe another with retracts someday.



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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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       Post #: 204

RE: Cold Duck - Build - 2/28/2006 6:11:06 AM   
Mike Denest



Posts: 725
Joined: 5/21/2002
From: Newark, DE, USA
Status: offline 		Mike,
There's nothing much that Tower can inspire me with either. Great job on the CD, it's nice to see a classic design fly again.


quote:

ORIGINAL: 8178

I’m not sure what to build next. I’ve been getting all kinds of email messages from Tower Hobbies about discounts on stuff but when I went to their website and looked at their flyer I cannot find a single kit that inspired me.




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R/C as it used to be: http://www.vintagercsociety.org

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       Post #: 205

RE: Cold Duck - Build - 6/25/2006 11:06:28 PM   
8178



Posts: 2941
Joined: 5/25/2004
From: _ , USA
Status: offline 		The Cold Duck has been flying for over four months now and after a great day of flying it today I thought I’d update the thread.

I’m very pleased with the way it flies. Very light and gobs of power for unlimited vertical and loops as big as you want. It is truly a joy to fly! Everyone that has seen it fly comments on how smooth it is.

Early on I had a problem with the RJL carbs that were on the oldest of the three engines. I put the newest carb on the older engine and it worked perfectly. RJL customer service quickly resounded to the problem and said it was related to the size of the low speed needle valve end. The RJL engine is excellent and their service is superb.

Increasing the horizontal stab and elevator size was a good change and I think it has improved the flight characteristics over the original. It will make very slow, nose high landings that are pretty neat. There is plenty of elevator power.

The main gear was a little bit too long and created too much of a nose down stance and I solved that by reforming the gear wire out further.

At 5 lbs 7.5 oz it is a little light in gusty wind but it is super smooth when the wind is steady. Even with the light wing loading it can be commanded into spins well including easily changing spin direction while in a spin.

My only regret is not building it with tri gear retracts. The extra weight of the retracts would have not been a problem at all.






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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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       Post #: 206

RE: Cold Duck - Build - 6/27/2006 7:27:54 PM   
8178



Posts: 2941
Joined: 5/25/2004
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Status: offline 		It is interesting that the power to weight ratio (5.468 lb – 1.8 HP = .0205) of the “new” Cold Duck” is almost identical to a typical 10.5 lb 2X2 ship with a 3.5 HP power plant (= .0208). Of course the typical 2X2 ship will have a wing loading of about 25 oz and the Cold Duck is only 19.3 oz. But I’m not sure if wing loading can be scaled very well because of the Reynolds numbers, e.g. 25 oz on 1000 sq. in. wing compared to 19 oz on a 650 sq. in. wing.

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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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       Post #: 207

RE: Cold Duck - Build - 7/9/2006 9:23:29 PM   
aerowoof


 

Posts: 1816
Joined: 6/11/2006
From: pembroke, NH, USA
Status: offline 		I have been wanting to build this model since i saw it in rcm 35 years ago,I now have the plans and foam cores as well as a set of kdh retracts that match the cas retracts on the plans.the kdh struts are about 1/2 longer than the struts shown but since i fly off grass will go with the extra length and just move the wheel wel.I will be using a hb 61 wth pdp for an engine.I was planning on building this stock per plans but am now reconsidering enlarging the stab and elevater as you did.My question is does the new cold duck fly better than the original due to the increased power and less weight or does the enlarged tail really help.since you flew the original what do you think.I will be using polyurethane and glass cloth for a base for paint instead of monokote and am shooting for a weight of under 6 1/4 pounds.

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       Post #: 208

RE: Cold Duck - Build - 7/9/2006 11:51:28 PM   
8178



Posts: 2941
Joined: 5/25/2004
From: _ , USA
Status: offline 		aerowoof

That is really neat that you’ve been Cold Duck fan for so many years and now it looks like you have all the stuff you need to get a build done. Plus a custom updated on-line build manual by the designer a mouse click away!

I thought it flew very well in 1969 but I always tried to reserve my excitement incase I’d been influenced by my design work. But as others saw it fly they commented on its flight characteristics and encourage me to get the design published.

The larger stab and elevator was worth the effort and improved the elevator power at slower speeds and added no negatives at high speed. With more elevator power it will make very slow nose high landings that are absolutely beautiful. Probably helps the snaps and spins as well. The guys in our club have been impressed with the new Duck’s flight characteristics and one of them is going to build one.

The old Veco 61 in the original didn’t have much power so the K.61 has been like supercharging the power! Probably twice the HP of the old Veco and I would think your HB 61 PDP power would be very close to the K.61. It is a little light in gusty winds at my current weight of 5.4 lbs and I would think it would be a great flyer at 6 ¼ lbs with the HB 61.

I’ve been told that the RCM Cold Duck article was very well received by the readers of RCM and many plans were sold but until the RCU build I didn’t have medium to get much feed back. Although in the early 70s I was on a business trip in Dayton Ohio and stopped by one of the hobby shops and a guy was building a Cold Duck!

I’ve really enjoyed flying the new Duck the last few months and I hope you will too. It would be great if could share your build experience with us on the forum.





< Message edited by 8178 -- 7/10/2006 4:18:42 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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       Post #: 209

RE: Cold Duck - Build - 7/10/2006 12:23:49 AM   
aerowoof


 

Posts: 1816
Joined: 6/11/2006
From: pembroke, NH, USA
Status: offline 		ok you have convinced me to go with the large tail,now about making the fuselage 1/2 narrower.i would like to build it as close to the original as possible but since there is a new original I am undecided.leaning towards the revised cold duck mods you presented more and more but doesn't that void the spa legal design parameters?if not then there is no reason not to do the revisions.Thanks.

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       Post #: 210

RE: Cold Duck - Build - 7/10/2006 12:35:29 AM   
aerowoof


 

Posts: 1816
Joined: 6/11/2006
From: pembroke, NH, USA
Status: offline 		8178,
forgot to ask, when you made the fuselage 1/2 narrower did you just modify f-2 and f-3 or did you take 1/2 off from the firewall thru f-4?thanks.also when you increased the span of the stab i am assuming that the tip and root chord remained the same?
by the way i will be using and updated Kraft 7Z tx and rx but futaba 130 servos and a 136g on the retracts.

< Message edited by aerowoof -- 7/10/2006 12:50:04 AM >

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       Post #: 211

RE: Cold Duck - Build - 7/10/2006 1:54:29 AM   
8178



Posts: 2941
Joined: 5/25/2004
From: _ , USA
Status: offline 		The SPA does not take measurements, so if it looks like a Cold Duck, it is a Cold Duck by SPA rules.

The original fuselage had to be pretty wide to fit the old monster size Kraft KPS9 servos. On the new Duck I took ¼” off each side of F2 and F3 and at the same time moved the firewall (F1) back 1/2” to make room for the longer engine. I left F1 the stock width but made it taller to fit the new space. By moving F1 back ½’ it automatically took care of the width adjustment. The ½” off the width also provides the ability to make the fuselage top more rounded. That all worked out well and retained the smooth lines of the original fuselage.

When I changed the span of the stab I kept the root and tip cord the same width as the plan and added 1/2 “ to the trailing edge of the elevators.



< Message edited by 8178 -- 7/10/2006 4:22:46 PM >

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Builder and flyer of high performance acrobatic R/C aircraft and a proud member of VR/CS.
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       Post #: 212

RE: Cold Duck - Build - 7/11/2006 11:03:00 PM   
aerowoof


 

Posts: 1816
Joined: 6/11/2006
From: pembroke, NH, USA
Status: offline 		8178,
last night I drew up the new sized formers as well as the othe formers and retract mounting plates in cad,If you want a set pm me your e-mail address and i will give you a copy ,you can check for accuarcy while I wait on my wood order.also if anyone else wants a copy drop me a line did not take much time as they were all straight lines.

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       Post #: 213

RE: Cold Duck - Build - 7/30/2006 5:16:05 PM   
aerowoof