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Old Dec 21, 2006, 09:36 PM
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Beaverdam Creek, VA
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Quote:
Originally Posted by canard addict
Beavrdam, What a great variety you have there. The Delta with open mid section has been on my agenda for some time now. How does it fly? Thanks for showing that, Cooper! Is it full scale? Charles
Thanks! The first flight was about 20' on that one. I fixed the nose, cut down on the aileron throw and moved the CG back a bit. That got a couple wild laps around the field, I need to cut down on the aileron throw some more and fix the nose again. Once I get it flying decently I'll put a second one together, hopefully I can keep that one from acting like a lawn dart. I have the pieces cut out and edged, the second fuse has a full balsa outline.

If the canard doesn't have positive incidence it won't be "loaded", and the CG will need to be farther back. The designs I've seen without incidence don't have movable surfaces on the canard, just elevons. I'm not sure if these qualify as true canards, they're more like a flying wing or a delta with some forward area. It could be fuselage area and function the same.

There are a couple items here about canards;
http://www.djaerotech.com/dj_askjd/askdesign.html

Good Luck!
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Old Dec 21, 2006, 09:39 PM
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RL: I noticed that the front part of the canard on my Shinden was a bit floppy, so a piece of 1/16 by 3/16 spruce was added as a brace. It may pay off in a fast pull up from a dive. You have to look well to see it. It does not interfere with the movement. Charles
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Old Dec 21, 2006, 10:13 PM
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Beaver, That link is awesome! I read it a couple of years ago. I guess intuition and trial and error have guided me through my modeling years. Regarding your thoughts on canard wing behavior: The COG of the Hobby Lobby Shinden is well into the main wing which seemed to take away the action of the tiny 20% canard. The model was sick on two lipos. I added more prop pitch for more speed which helped a bit. I figured the canard needed 6 inches more area to fly slow. I ended up with 3 more sq. inches on the canard, added a cell and moved the COG forward. At higher speed and more load on the canard, It is now much more fun. Charles
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Old Dec 21, 2006, 11:27 PM
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Indiana
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Sig Tri-Star. Flies on 300+ watt electric or Aerotech 32mm rockets.

Electric setup is a Mega 16/15/5, geared 2/1, 11x8 carbon folder.
4s 1p Polyquest 2200. Went back and checked my log. It's about 360 watts static on a fully charged pack. A 15 second motor run takes it to about 1000'. The plane will thermal well in moderate lift but it's not an all out sailplane.

The rockets... Ya know, sometimes i get these crazy ideas. This plane was one of them. On rocket power it's flying weight is about 8oz. lighter than the electric setup so it does thermal a little better. The TriStar flies very well off the launch rack 90% of the time. It has no movable rudder so if it yaws coming off the rack it can be a handful. That's what you see in the video i linked to. If it yaws you have to roll and pull elevator to compensate. If i had it to do again i would probably add more sweep to the wing to make the vert. stabs more effective. Rockets make 10 lbs of thrust and burn time is 6 seconds. Costs $8usd per motor so it aint cheap!


http://www.rcgroups.com/forums/showthread.php?t=597881
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Old Dec 21, 2006, 11:53 PM
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I picked up this Multiplex Sonic Liner a few months back after they were discontinued in the USA. Twin brushless, LiPo. Very kick back easy to fly. Looks neat in the air too.
Rick
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Old Dec 22, 2006, 06:09 AM
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Icrashrc, That is a beautiful Tristar and it must really move with 300 watts! I can't believe how well it looks after enduring rocket flights. Can you give us a description or series of events of the rocket flight. I wanted a Tristar but could never find one. Charles
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Old Dec 22, 2006, 09:35 AM
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Sonic Liner, Lennon Canard Book

Rick, You were lucky to find your Sonic Liner, They look awesome against a blue sky. Too bad that Boeing built the Airbus instead.What brushless motors did you use? At the last two Little Rock SMALL meets, four pilots have taken their SL's up for formation flights. They made multiple passes across the field and it was an incredible show. If you love canards, The book by Andy Lennon is a must have. It covers all that were built from the Wright brothers up to 1984. It is by Aviation Publishers,Hummelstown, Pa. with Motorbooks International, Osceola,Wisconsin listed as distributors. I was lucky to find mine on Ebay. Charles
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Old Dec 22, 2006, 09:42 AM
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Charles,i was lucky enough to find a Simprop Piaggio Avanti to go along with my Long EZ 380. It should be here soon(hopefully before christmas) but i will start on it as soon as i get it. I'm going to work for a air sampling company testing edf's soon so tomorrow is my last day at the HL craftstore. Should give me the time to build. I plan on dual 28mm brushless and lg,possibly air retracts
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Old Dec 22, 2006, 11:38 AM
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This thread is awesome! To much to assimilate all at once. How does the Hobby Lobby Shinden fly?
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Old Dec 22, 2006, 12:33 PM
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Mustang: You have two quick models there! As you know, I have assembled the Long EZ and I dearly love the Avanti with it's three horizontal surfaces. If it had Landing gears, I could not have resisted getting one.I hope to see you again at an event with your planes. Tometech, the Shinden was fun to assemble, and is fun to look at and fly. I do not regret the experience. Mine has the AXI 2204-54 with three lipo 800's and the GWS 7.35 prop. The efficiency is in the 70s and it pulls about 5.3 amps at 57 watts.(91 watts per pound). I added three sq. inches to the elevator (see picture) and moved the cg a bit forward. It is quick and gets good attention at the field. I especially enjoy knowing that only two were built in 1944, they were intended to go after the B29s at 459 mph. We have one in Washington, I believe. Please don't attempt to go with two cells.
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Old Dec 22, 2006, 06:06 PM
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Canard Addict: Some of the Canards are built for lift and some are flat. How much difference does it make? Will the Slow Stick canard fly with a flat canard? Does it matter whether the verticle fins are inboard or on the wingtip?
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Old Dec 22, 2006, 09:04 PM
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Just got here from work and unpacked the Avanti. Box pic makes it look gorgeous but that's all i can see til christmas.
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Old Dec 22, 2006, 09:36 PM
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Tometech: My Slow Stick canard has a flat bottom canard, the Pico Stick canard has a 1/8" thick flat foam canard, my Soar Star canard has the under cambered Parkzone canard and all fly very well. I find that the flat bottom airfoil is capable of taking my models up in a hurry. I use them on my own designs. I associate them with the Clark Y or scale J3 Cub type. I believe that too much under camber can cause a model to tuck under in a dive. This tuck under has been demonstrated to me with the Wingo and the Firebat. On my Wingo and Soar Star canards, I file the wing bottoms nearly flat. This was done on my stock Wingo and allowed the model to fly flat and fast. The Slow Stick canard is so stable and forgiving that the balance point is not too critical and you could put any of the three types of front wing on it and probably not know the difference. To me, canards are the easiest of all types to design with success. The Pico Stick was simply turned around with the stock parts and the magic angles and COG were applied and it flew perfect.I put the Winglets just where I feel they need to be and have never had an issue with stability. Some canards have a single rudder in the center rear, some like the Vari Viggen have two close in and others are on the wing tips. The fins that are the most rearward from the COG are the best. Some designers sweep the wing trailing edges back to achieve this. If you will build the Slow Stick as described in this thread, you will love it. If anyone wants the Piconard details, I will be glad to give them here. go to www.m-a-e.com and see my Piconard fly. There are two videos there on it.
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Old Dec 22, 2006, 10:26 PM
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Canard airfoils....

On my Starliners, the canards all use an eppler 214 airfoil, set at an incidence angle of 1 degree. (main wing at 0 degrees) I had tried 2 degrees but the elevator response went "dead". It took a large amount of movement to get a reaction from the plane, it flew fine, just seemed stuck at level flight. (CG stayed the same). Guess I could of moved the CG for better response and stayed at 2 degrees, but it was easier to remove the shim I used to alter the incidence angle.

I think I read somewhere that airfoils do not make much difference if the chord is less than 5 inches. (small Reynolds numbers?) On my planes, only the Mk IV has a chord of 5 inches, the rest are less than that, 4" on the Mk III and 3.25" on the Mk V. On these two, the airfoils didn't amount to much, the MK III ended up close to a simple clark y foil, and the Mk V is just about a flat plate. Both of these planes fly the same. The Mk IV at 5" has a good airfoil, a more crisp elevator response and behaves better when the canard stalls, nice nose up and down motion.

Bottom line, I would say if the chord of a canard is less than 5", the airfoil does not matter, only the incidence angle matters, 5" and over, the correct airfoil can improve the handling of the plane. YMMV!

Had my Mk IV out today, almost calm winds 70 degrees, sunny, ah the joys of Texas in winter!

Later!
Chuck...
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Old Dec 22, 2006, 11:59 PM
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Canard wing behavior Starliner

Cwesh, Thanks for the interesting discussion on the behavior of your canard wings. Your planes look fast to me and with the small canard areas, the COG must be close to the main wing. The small aspect ratio of the front wings will cause a quicker stall. I wonder if at 2 degrees with high speed the air flow could be breaking away at the top causing a dead spot around the elevator. My Shinden had the COG well into the main wing and the small 20% canard seemed to be just a toy with little effect. It was slow on two cells and I had to hold 1/2 up elevator during the first flight. I confess that I had the COG a bit forward because the calculator disagreed with the instructions. It was almost like it needed elevons. When the power was doubled,more area added to the canard and cog moved forward, the character of the model completely changed. Maybe you should add area by extending the canard center chord forward and make a swept back leading edge,increase the angle to say 2.5 and bring the COG foreward. The swept back LE acts as dihedral. I really know very little about your beautiful ship and just let my mind ramble.Please tell us more.. Charles
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