HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Feb 20, 2013, 10:59 PM
who has rabbit ears down
Captain Canardly's Avatar
United States, MN, Buffalo
Joined Jan 2007
3,631 Posts
Finally getting things done here's apreview of what's been up! Going to do up a full BOM to see how close the CAD says to reality!
Captain Canardly is offline Find More Posts by Captain Canardly
RCG Plus Member
Latest blog entry: One printer running!
Reply With Quote
Sign up now
to remove ads between posts
Old Feb 21, 2013, 02:34 AM
Registered User
Trevorh's Avatar
Hampshire, U.K.
Joined Jun 2008
1,896 Posts
Well done Nick, models look so much better cruising around at a sensible speed, and videos usually make them look a bit fast. Not so this one - it looks beautifully steady and controllable.
Trevorh is online now Find More Posts by Trevorh
Reply With Quote
Old Feb 22, 2013, 09:31 AM
Lighting Up the Darkness
United States, GA, Loganville
Joined Jan 2013
23 Posts
Nick,
Wow. What a terrific flyer, and impressive finish on the aircraft. I'm inspired to plan a project using Depron......but I have a hunch that my Depron project might not be as pretty as yours. I really enjoyed your flight!
nightlightrepair is offline Find More Posts by nightlightrepair
Reply With Quote
Old Feb 22, 2013, 10:20 AM
What could possibly go wrong?
nickchud's Avatar
Market Harborough
Joined Apr 2006
3,739 Posts
Many thanks for your encouragement guys!

I'm still working on the finish, when I get a chance. I think the secrets with Depron are:

1: You can bend it a lot if you put tape on the outside of the bend.
2: The skin provides most of the strength. If you sand it or cut it off, you can repair the finish with lightweight spackle.
3: WBPU restores the strength a little. You can mix any old acrylic paint into the WBPU and it will be water resistent. 2 or 3 coats and some fine sandpaper make a good finish.
4: 0.6 oz glass cloth adds a little to the weight - about an ounce for 300sq inches of wing area as far as I can judge. It adds tremendously to the strength and stiffness.
5: on top of the glass cloth, after the first layer of WBPU has been brushed in and allowed to set, use a mixture of WBPU and spackle. Squeegee it across the surface with an old credit card. Then go to stage 3 above.

I've only used the glass cloth on the wings (top and bottom). I'm tempted to make the final coats of colour using a foam safe aerosol - it's an easy way to avoid the brush stokes. I would be pleased to hear any advice on this.

cheers

Nick
nickchud is online now Find More Posts by nickchud
Reply With Quote
Old Feb 22, 2013, 03:03 PM
Registered User
Joined Jun 2005
2,465 Posts
Equaduck

My progress is slow but every minute is enjoyed. About half of my time in the hobby room is spent just looking at the structure and planning the remaining steps. A good friend told me years ago to spend a little time building each day and one day it will be finished. The only problem that I see with this model is the short distance between the wing's TE and the ground. It will be dependent on the length of the tail wheel. My Egret has the same problem.

The Twin was flown twice last evening and was enjoyed much. The three point landings are as easy as the Delta Duck.

Charles
canard addict is offline Find More Posts by canard addict
Reply With Quote
Old Feb 22, 2013, 03:10 PM
Registered User
Don Stackhouse's Avatar
United States, OH, Bradford
Joined Jun 2005
4,076 Posts
You feel that is a problem because??
Don Stackhouse is online now Find More Posts by Don Stackhouse
Reply With Quote
Old Feb 22, 2013, 03:39 PM
What could possibly go wrong?
nickchud's Avatar
Market Harborough
Joined Apr 2006
3,739 Posts
Nice collection of canards Charles, beautiful! I didn't know you had 2 Delta Ducks. Twins are fun to fly, don't you agree? You don't need to build quite as fast as me, 'cos you don't crash them so often.

TE close to the ground? Does the ground effect mean that, on take-off, the wing will start to produce lift before the canard?

Cheers

Nick
nickchud is online now Find More Posts by nickchud
Reply With Quote
Old Feb 22, 2013, 04:10 PM
Registered User
Joined Jun 2005
2,465 Posts
Low wing ground clearance

Don
Quote:
You feel that is a problem because??
I cannot feel a difference in ground effect but grass landings could cause damage to the covering. The winglets on the Egret are bare underneath from landing on pavement. It's rainy today so no evening flying.

Charles
canard addict is offline Find More Posts by canard addict
Reply With Quote
Old Feb 22, 2013, 04:16 PM
Registered User
Don Stackhouse's Avatar
United States, OH, Bradford
Joined Jun 2005
4,076 Posts
Reasonable concern, but good judgement in covering (I'd suggest regular weight Ultracoat/Oracover) and careful selection of landing area should keep things under control. A lot of belly-landing aircraft (including a lot of sailplanes) face similar issues.
Don Stackhouse is online now Find More Posts by Don Stackhouse
Reply With Quote
Old Feb 22, 2013, 06:09 PM
Registered User
p901P901's Avatar
United States, CA, Lancaster
Joined Jan 2009
1,260 Posts
HS p-75

I have a question on canard elevator surface area, D/R and Expo.
My present build is here:http://www.rcgroups.com/forums/showp...9&postcount=15 and continues through to http://www.rcgroups.com/forums/showp...1&postcount=26.
Canard area is 20% of the main wing. Canard is a E217 and will have 3 degrees positive incidence.
Main wing is a E197 with 1 degee incidence with outer control surface as ailerons and inner as secondary elevators. Secondary elevators are there to help in turns with about 5 degrees down and 20 degrees up max travel.
Airfoil coenfecants are set up so the wings will have the proper stalls for canard aircraft. I just do not know the set up for the canard elevator and if the secondary elevator is really needed
Thanks
p901P901 is offline Find More Posts by p901P901
Reply With Quote
Old Feb 22, 2013, 06:27 PM
Registered User
Joined Jun 2005
2,465 Posts
P901, Your design looks good to me. I do not believe that you will need elevators at the rear since you have rather long moment arm up front. Also the moment arm for the rear elevators will be short. The airfoil selections look good with the main wing stalling after the canard.

Charles
canard addict is offline Find More Posts by canard addict
Reply With Quote
Old Feb 22, 2013, 07:33 PM
who has rabbit ears down
Captain Canardly's Avatar
United States, MN, Buffalo
Joined Jan 2007
3,631 Posts
901: Sure looks tastey! I take it the revs are from the original story?
and Sarah:
Captain Canardly is offline Find More Posts by Captain Canardly
RCG Plus Member
Latest blog entry: One printer running!
Reply With Quote
Old Feb 22, 2013, 10:14 PM
Registered User
p901P901's Avatar
United States, CA, Lancaster
Joined Jan 2009
1,260 Posts
Quote:
Originally Posted by canard addict View Post
P901, Your design looks good to me. I do not believe that you will need elevators at the rear since you have rather long moment arm up front. Also the moment arm for the rear elevators will be short. The airfoil selections look good with the main wing stalling after the canard.

Charles
Thanks for your advice. From previous designs I did have elevons on the main and a flying canard in the front. Without realizing the dynamics of canard aircraft I found the varying incidence of the flying canard caused the bad stalling tendencies.
So I will use about 30% of the area of the canard as the elevator and about 1/2 span of the main wing section as the aileron. I guess control throws and expos will be up to experimentation.
Thanks
p901P901 is offline Find More Posts by p901P901
Reply With Quote
Old Feb 22, 2013, 10:24 PM
Registered User
p901P901's Avatar
United States, CA, Lancaster
Joined Jan 2009
1,260 Posts
Quote:
Originally Posted by Captain Canardly View Post
901: Sure looks tastey! I take it the revs are from the original story?
and Sarah:
I made from a profile to one with a 44" wing span and all flew. Back then I did not have a concept of how the canard stalls in comparison to the main wing.
And have een lurking in this thread and reading the experts opinions and have been learning allot.
After this comes the Lockheed L-133 http://www.rcgroups.com/forums/showt...ghlight=lockhe

Thanks and will need suggestions.
p901P901 is offline Find More Posts by p901P901
Reply With Quote
Old Feb 23, 2013, 12:05 AM
who has rabbit ears down
Captain Canardly's Avatar
United States, MN, Buffalo
Joined Jan 2007
3,631 Posts
UFFDA That Lockheed looks challenging! apair of 90's is sure gonna haul the mail! Have you looked @ the disk areas conversations @ EDF?
Captain Canardly is offline Find More Posts by Captain Canardly
RCG Plus Member
Latest blog entry: One printer running!
Reply With Quote
Reply


Thread Tools