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Old Jul 19, 2007, 10:19 AM
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No John, Thankfully the main wing has never stalled. I have had problems with the main wing lifting off first and killing the angle of attack up front causing the nose to drop into the ground where the nose gear gave it a bounce upward which increased the AOA of the main wing which started a repeat performance. The model hopped like a kangaroo. This has happened on three designs. I found that a zero or negative AOA of the main wing relative to the thrust line has been good. At the same time I found that the canard did well if it was at least 30% of the area of the wing. I am also stuck on 3.5 degrees of decalage between the wings especially on long coupled models. I now hope to find out how the short coupled canard needs to be set up. My favorite planes have 4 ft. spans, weigh around 2 pounds, cruise around 30 mph and stall around 15. The specs that I use have been great so far. The Voyager was shorter coupled, weighed 44 oz.,had less decalage and less canard percentage area and was faster. This Delta is just my best guess to fly. Thanks to Magic 612, the control system should be the best. We will soon find out. I will be nervous on maiden. Charles
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Old Jul 19, 2007, 04:41 PM
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Ocala,Florida
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PJ,regarding the Nitroplanes and Raidentech Rutan Diefiant, I plan to put together an electric one in the near future with two outrruners,similiar to my 55" 337 that flies on two park 480's and a 3200 3 cell.
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Old Jul 19, 2007, 09:23 PM
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Sydney, Australia
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My new project

Following the discussion of canard incidence, I will try something different for my new project. My new design will use a semi-symmetrical airfoil for the main wing and a Eppler 205 flat bottom section for the canard wing. The main wing airfoil is a NACA 1410 which only has 1% camber, but I have increased the thickness to 11% from the original 10%.

With flat bottomed airfoil sections the bottom profile is not the same as the mean camber line. For example with the Eppler 205, by mounting the airfoil on its flat bottom, you end up with a positive incidence of the mean camber line by around 1.9 degress. For my design the canard will be mounted with screws that fix into blind nuts on a plywood mounting pate. That will allow me to adjust the the incidence or redesign the forplane if it turns out to be too small etc.

As for the planform, the aspect ratio of the forplane (5.6) will very similar to the main wing (5.0). Although the foreplane aspect ratio is slightly higher, I call it a draw because of the 60% taper ratio in the main wing .

Although I don't have test data for both aifoils under the same conditions, I think that in application of a small model, the NACA 1410 may theoretically stall at lower angles of attack than the E205, mainly because it has less camber. However, since the forplane will be half the span and around 20% of the area of the main wing, I expect it stall earlier even with only modest decalage of 2 of 3 degress relative to mean chord line of the main wing. I really don't know if this is being optimistic or not.

Comments on my design are very welcome.
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Old Jul 20, 2007, 08:18 AM
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John, Your design looks great! My machine would not open the zip file. Are you sure about the 20%? It looks greater to me. On my flat bottom designs, I use the flat bottom as zero and measure the 3.5 degrees canard incidence relative to the main bottom. If my Delta performs well, I may try a semi symetrical airfoil for better inverted flight.My modeling seems to revolve around trying to get out of work. It is my belief that the original design and scratch building is where it's at. Too bad I waited so long to try it. I look forward to seeing your progress. Charles
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Old Jul 20, 2007, 01:24 PM
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Charles, I will share the Defiant with the canard community when I get to do it
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Old Jul 20, 2007, 04:54 PM
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Delta Canard Landing Gear

So far, today has been lazy. Went to the store for hard wood and 3/32" wire. The landing gear bending went well. I tried the Andy Lennon style gear but did no want to use it because of the long and skinny wire which probably would have caused too much mush up front. Maybe next time with a short fat wire. There is lots of room on the gear for some balsa coverings. Charles
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Old Jul 20, 2007, 06:03 PM
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that is looking very cool Charles. I'll be up your way tomorrow and Sunday for Mac's jet rally. If you could make it, I'd like to buy a set of plans for the GA Goose from you
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Old Jul 20, 2007, 07:57 PM
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Somewhere south of Chicago, IL
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Quote:
Originally Posted by canard addict
Thanks to Magic 612, the control system should be the best. We will soon find out. I will be nervous on maiden. Charles
You and me both - and I won't even be there!!!

(I certainly hope it is the best control system for you on this plane, Charles - all I know is what worked well for my J1-31!)
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Old Jul 20, 2007, 09:59 PM
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Magic, How about 3/8 to 1/2" movements on my surfaces and about 50% expo? I read your blog and was impressed.Charles
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Old Jul 21, 2007, 09:31 PM
Bernoulli+Newton=Lift
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Quote:
Originally Posted by canard addict
Magic, How about 3/8 to 1/2" movements on my surfaces and about 50% expo?
Sounds like a good place to start to me.

Quote:
Originally Posted by canard addict
I read your blog and was impressed.Charles
You give me far more credit than I deserve - but... thank you.
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Old Jul 22, 2007, 03:52 AM
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Charles, The previous files in the zip archive were created by windows image writer. Now I attached the image files as gif. The resolution won't be as good, but at least you will see what I am talking about.

The model will be really small with a wing span of only 80cm, root chord 20cm, and tip chord 12cm. The forplane will be 40cm span with 8cm root chord, and 6cm tip chord. By my calculation the forplane is around 21%.

Building small models is my idea of getting out of work. My construction will be pretty basic with balsa sheet box section fuselage. I just finished a biplane model with lots of curves and sheet planking. My patience for complex builds has pretty much run out. I don't find symmetical sections all that difficult. All you need is a balsa strip to lift the trailing edge of the building board. Personally, I start by glueing the ribs to the trailing edge before pinning anything down to the building board.
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Old Jul 22, 2007, 12:23 PM
Survival is Attitude!
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Hallsville Texas
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I am watching web sites for when the Longeze comes available. The canopy would be a good place to put instruments, camera etc. Also been watching VariEze since September 1974, when Air Progress did the first article on Rutan.
Still have it too.
I just love the planform shape. Have one flying in the area, just loads of fun to watch!
For those who already have one, how big a prop can be run? Need to start deciding what to use. And I have seen the same plane advertised at 34 ounces and 5.5 lbs. A lott of import websites have omissions or bad data, Its the language barrier from what I can tell. Which weight should I consider?
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Old Jul 22, 2007, 11:33 PM
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Delta Progress

John, It's looking good. Thanks for showing the airfoils. Your model will span about 33" as I figure. Not a bad size and a lot less work. I will do most anything to save work. This Delta has been easy. SS Texas, My LEZ was designed for electric and finished out at 44 ounces as I recall. The heavier ones were designed for wet engines and would be expensive to power. Mine, with the Medusa speed 400 size used an 8-4 APC and has lots of power. Today, I installed the nose gear and added the top cowling. Charles
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Old Jul 23, 2007, 09:37 PM
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Landing Gear Dress

The Landing gear covers were made today. Canopy glue holds tight to metal but will take until tomorrow to set for sanding. Charles
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