control surfaces for canard?

t-turley · Jun 26, 2002, 10:30 AM

I'm about to start cutting some foam for a small canard, about 30" WS. I'm debating whether to use elevons or a moveable canard and ailerons. I've also considered REM control, with a rudder on the back and a moveable canard up front. I've read Don Stackhouse's treatise on canards, and Chris Golds's opinion on canard efficiency. I'm tempted to just give it a whirl and see what happens. After all, it's only just a few $$$ of foam core. But if anyone has some experience with this matter - and not just anecdotal evidence - I'll take any information you can give.

iamDerrick · Jun 26, 2002, 12:56 PM

I've made an ips powered plane with a canard config .
had about a 30 inch span main wing with a 5inch chord.
the canard had an 8 inch span with a 4 inch chord

made it in about an hour and was too lazy to make servo connections for pitch control on the canard and so just left it with elevons.
flew pretty ok.but didnt last very long at all.

you should probably be more concerned about find a decent CG placing for your first few flights with a canard

Sparky Paul · Jun 26, 2002, 01:38 PM

I took my original Renger "Foam Fatale" foam-board delta and made a canard for it.
The first version with the narrow chord canard was a poor performer on the slope.
Seriously adding chord to the elevator improved that a LOT.
Then, the Achilles Heel of canards reared its ugly head.. the control surfaces hit the rock, bush, tree, leg first..
Broke one side completely off.
Flew it anyway..
Somewhere in the archives is an inflight of it with only one side..
Here's 3 of the 4 versions of the Fatale...

Dereck · Jun 26, 2002, 03:01 PM

Hi Tony
Way back, before I left England, a buddy of mine scaled up a FF rubber powered canard to match the old Ace moulded foam wings. This had an 049 up its backside, but one did subsequently fly real good on some sort of 400.

Anyway, he had pitch on the foreplane and roll on the ailerons. Kinda boring but it went real well. Aerobatic, pretty smooth flier, all the good stuff. His was kind of mid to low wing, foreplane a little higher than the mainplane.

If you go REM, same rules apply as for regular shapes - dihedral to give you the turning after rudder is applied, high wingers are probably better than low. Like you say, a couple of $$ of foam. Or do the Golds thing and make up a large scale model to chuck around just to see how what does what. This allows you to establish a CG location ballpark without risking expensive stuff like radio gear.

I always fancied that Gee Bee Ascender canard the Granvilles cobbled together.

Flyfan · Jun 26, 2002, 03:45 PM

Hi t-turley, I've been planning an IPS foam canard too. I was thinking about a Concord style wing as I love that shape and delta's seem very 'floatable'

I've read several things on canards, mostly positive and it makes sense for an elevator to provide lift rather than downforce.

Please could you point me to "Don Stackhouse's treatise on canards, and Chris Golds's opinion on canard efficiency"

My current idea is to have a delta wing with no control surfaces and a v shaped canard ( ~100 degrees) with elevons. The canard will have to be a reasonable size, I think. Does anyone know if this will work ?

Rob

t-turley · Jun 26, 2002, 06:27 PM

Thanks for all of your replies. After more careful consideration, I think I'll go with AEM, with a moveable elevator on the canard, and sort of a high wing config, like Andy Lennon's "Canada Goose". Flyman, here's the link to the Stackhouse article: http://www.djaerotech.com/dj_askjd/d...ns/canard.html . If you go to their main page, click on "Ask J & D", then type "canard" in the search box, you will find a bunch of articles that discuss canards in one way or another, and this article is the first one. Chris Golds had a Sp400 Ki-61 Shinden plan review published in EFI some time ago. Basically, his take on canards is that a moveable canard is not a good thing. I'm going to give it a shot. My plane will be small enough that I can stick my Rx, servos, and a 110mAh Rx pack on it, and toss it around my yard to fine tune the CG and control throws. That's how I've been fine tuning the control setup on a foamie I'm just finishing, after making a 40% size model of the model

to get the CG in the ballpark.

genovia · Jun 27, 2002, 02:20 AM

What's Carnard's funtions in flight?

t-turley · Jun 27, 2002, 10:43 AM

This is from an aerodynamics site I found:

Quote:

A Canard aircraft is one in which the horizontal stabilizer and elevators are ahead of the main wing. Such aircraft still have the same controls as the conventional aircraft they are just in different places.

Here's an example of a canard a/c, one known as the Cozy:

Flyfan · Jun 30, 2002, 09:45 PM

t-turley, thanks for the link to DJ Aerotech, that's a massive site - everything you ever wanted to know, a very valuable link.

I read several things there that have totally depressed my plans for a canard. According to the info there's not much difference in performance between canard and usual config.

One big advantage of the canard is it's unusual shape, hope I get enthusiastic again, I wanted to try the V shaped canard as elevons, haven't seen that anywhere on my travels (perhaps it doesn't work !)

How's yours going ?

Rob

t-turley · Jun 30, 2002, 09:53 PM

Rob,

Mine's going great! I was just out in the yard, tossing it around as a FF glider to get the CG right. It has a beautiful glide - but of course, what glides wonderfully at 2 oz may glide like a brick at 8 oz.

Here's an early photo. The popsicle sticks on the canard are to hold the elevators in neutral for the test glides.

nolasco · Jun 30, 2002, 11:29 PM

Tony,

Your main wing look nice. What is it made of?

Jun Nolasco

t-turley · Jul 01, 2002, 06:41 AM

Jun,

The main wing is depron, with a hard skin. I picked it up at a LHS for $2.50. It's from a Megatech Airstrike.

nolasco · Jul 01, 2002, 03:09 PM

Tony,

I could be wrong, but those "ribs" make it look more like the wings of the Merlin.

In any case, that's $2.50 for a wing!!! My LHS sells the AirStrike wing for $17.99 and Merlin wing for $19.99.

I'd like to hear how your canard aircraft does.

Jun Nolasco

Flyfan · Jul 01, 2002, 04:02 PM

I like the way you've made that ff - so simple. Envious of the wings. Canards often look back to front and the forward angle of those wings helps that illusion - are you planning rear mounted motor ? Why is your computer in the middle of the room ?

Rob

t-turley · Jul 01, 2002, 11:21 PM

Jun,

I have a Merlin, too. The ribs on those wings aren't quite so pronounced. I was pleased to get the Airstrike wing at that price, too.

Rob,

Yes, I'll be using a pusher, most likely a rewound CD-ROM motor. As for the PC, I've been doing some pro bono computer work, helping out some friends and family. The computer in the photo belongs to my Mom. As I took that photo, I was sitting in a chair with my back to the PC I'm using now.

I'll keep you guys posted on the status of the canard. I hope it won't be too long before it's airborne.

Jun 26, 2002, 10:30 AM	#1
t-turley For Andy... Join Date: Mar 2001 Location: Scott Depot, WV, USA Posts: 1,587	control surfaces for canard? I'm about to start cutting some foam for a small canard, about 30" WS. I'm debating whether to use elevons or a moveable canard and ailerons. I've also considered REM control, with a rudder on the back and a moveable canard up front. I've read Don Stackhouse's treatise on canards, and Chris Golds's opinion on canard efficiency. I'm tempted to just give it a whirl and see what happens. After all, it's only just a few $$$ of foam core. But if anyone has some experience with this matter - and not just anecdotal evidence - I'll take any information you can give.

Jun 26, 2002, 01:38 PM	#3
Sparky Paul Ascended Master Join Date: Oct 2000 Location: Palmdale, CA Posts: 10,520	I took my original Renger "Foam Fatale" foam-board delta and made a canard for it. The first version with the narrow chord canard was a poor performer on the slope. Seriously adding chord to the elevator improved that a LOT. Then, the Achilles Heel of canards reared its ugly head.. the control surfaces hit the rock, bush, tree, leg first.. Broke one side completely off. Flew it anyway.. Somewhere in the archives is an inflight of it with only one side.. Here's 3 of the 4 versions of the Fatale... Attached Thumbnails 54.9 KB · Views: 431

Jun 30, 2002, 09:53 PM	#10
t-turley For Andy... Join Date: Mar 2001 Location: Scott Depot, WV, USA Posts: 1,587	Rob, Mine's going great! I was just out in the yard, tossing it around as a FF glider to get the CG right. It has a beautiful glide - but of course, what glides wonderfully at 2 oz may glide like a brick at 8 oz. Here's an early photo. The popsicle sticks on the canard are to hold the elevators in neutral for the test glides. Attached Thumbnails 25.2 KB · Views: 295

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Jun 26, 2002, 12:56 PM	#2
iamDerrick Registered User Join Date: Dec 2001 Posts: 138	I've made an ips powered plane with a canard config . had about a 30 inch span main wing with a 5inch chord. the canard had an 8 inch span with a 4 inch chord made it in about an hour and was too lazy to make servo connections for pitch control on the canard and so just left it with elevons. flew pretty ok.but didnt last very long at all. you should probably be more concerned about find a decent CG placing for your first few flights with a canard

Jun 26, 2002, 03:01 PM	#4
Dereck Visitor from Reality Join Date: Dec 1996 Location: College Park, Maryland, United States Posts: 8,419	Hi Tony Way back, before I left England, a buddy of mine scaled up a FF rubber powered canard to match the old Ace moulded foam wings. This had an 049 up its backside, but one did subsequently fly real good on some sort of 400. Anyway, he had pitch on the foreplane and roll on the ailerons. Kinda boring but it went real well. Aerobatic, pretty smooth flier, all the good stuff. His was kind of mid to low wing, foreplane a little higher than the mainplane. If you go REM, same rules apply as for regular shapes - dihedral to give you the turning after rudder is applied, high wingers are probably better than low. Like you say, a couple of $$ of foam. Or do the Golds thing and make up a large scale model to chuck around just to see how what does what. This allows you to establish a CG location ballpark without risking expensive stuff like radio gear. I always fancied that Gee Bee Ascender canard the Granvilles cobbled together.

Jun 26, 2002, 03:45 PM	#5
Flyfan Rob H Join Date: Jun 2002 Location: Cairns Australia Posts: 566	Hi t-turley, I've been planning an IPS foam canard too. I was thinking about a Concord style wing as I love that shape and delta's seem very 'floatable' I've read several things on canards, mostly positive and it makes sense for an elevator to provide lift rather than downforce. Please could you point me to "Don Stackhouse's treatise on canards, and Chris Golds's opinion on canard efficiency" My current idea is to have a delta wing with no control surfaces and a v shaped canard ( ~100 degrees) with elevons. The canard will have to be a reasonable size, I think. Does anyone know if this will work ? Rob

Jun 26, 2002, 06:27 PM	#6
t-turley For Andy... Join Date: Mar 2001 Location: Scott Depot, WV, USA Posts: 1,587	Thanks for all of your replies. After more careful consideration, I think I'll go with AEM, with a moveable elevator on the canard, and sort of a high wing config, like Andy Lennon's "Canada Goose". Flyman, here's the link to the Stackhouse article: http://www.djaerotech.com/dj_askjd/d...ns/canard.html . If you go to their main page, click on "Ask J & D", then type "canard" in the search box, you will find a bunch of articles that discuss canards in one way or another, and this article is the first one. Chris Golds had a Sp400 Ki-61 Shinden plan review published in EFI some time ago. Basically, his take on canards is that a moveable canard is not a good thing. I'm going to give it a shot. My plane will be small enough that I can stick my Rx, servos, and a 110mAh Rx pack on it, and toss it around my yard to fine tune the CG and control throws. That's how I've been fine tuning the control setup on a foamie I'm just finishing, after making a 40% size model of the model to get the CG in the ballpark.

Jun 27, 2002, 02:20 AM	#7
genovia The One.... Join Date: Jan 2002 Location: San Jose, Ca. Posts: 5,758	What's Carnard's funtions in flight?

Jun 30, 2002, 09:45 PM	#9
Flyfan Rob H Join Date: Jun 2002 Location: Cairns Australia Posts: 566	t-turley, thanks for the link to DJ Aerotech, that's a massive site - everything you ever wanted to know, a very valuable link. I read several things there that have totally depressed my plans for a canard. According to the info there's not much difference in performance between canard and usual config. One big advantage of the canard is it's unusual shape, hope I get enthusiastic again, I wanted to try the V shaped canard as elevons, haven't seen that anywhere on my travels (perhaps it doesn't work !) How's yours going ? Rob

Jun 30, 2002, 11:29 PM	#11
nolasco Registered User Join Date: Dec 2000 Location: New York, NY Posts: 1,298	Tony, Your main wing look nice. What is it made of? Jun Nolasco

Jul 01, 2002, 06:41 AM	#12
t-turley For Andy... Join Date: Mar 2001 Location: Scott Depot, WV, USA Posts: 1,587	Jun, The main wing is depron, with a hard skin. I picked it up at a LHS for $2.50. It's from a Megatech Airstrike.

Jul 01, 2002, 03:09 PM	#13
nolasco Registered User Join Date: Dec 2000 Location: New York, NY Posts: 1,298	Tony, I could be wrong, but those "ribs" make it look more like the wings of the Merlin. In any case, that's $2.50 for a wing!!! My LHS sells the AirStrike wing for $17.99 and Merlin wing for $19.99. I'd like to hear how your canard aircraft does. Jun Nolasco

Jul 01, 2002, 04:02 PM	#14
Flyfan Rob H Join Date: Jun 2002 Location: Cairns Australia Posts: 566	I like the way you've made that ff - so simple. Envious of the wings. Canards often look back to front and the forward angle of those wings helps that illusion - are you planning rear mounted motor ? Why is your computer in the middle of the room ? Rob

Jul 01, 2002, 11:21 PM	#15
t-turley For Andy... Join Date: Mar 2001 Location: Scott Depot, WV, USA Posts: 1,587	Jun, I have a Merlin, too. The ribs on those wings aren't quite so pronounced. I was pleased to get the Airstrike wing at that price, too. Rob, Yes, I'll be using a pusher, most likely a rewound CD-ROM motor. As for the PC, I've been doing some pro bono computer work, helping out some friends and family. The computer in the photo belongs to my Mom. As I took that photo, I was sitting in a chair with my back to the PC I'm using now. I'll keep you guys posted on the status of the canard. I hope it won't be too long before it's airborne.