Simon's Canard.

[NorthernBoater]

What thicknesses of balsa are you using?

[Simon.O.]

What thicknesses of balsa are you using?

The main body has 3mm sides, 2.5mm bottom and 2mm foredeck
Sponsons are 3mm inside skin 2.5mm bottom and outside skin with 2mm tops
Wing skins are 1.5mm
front step is a mix of 4mm to 2mm
Transom is 4mm ply
Motor mount is 2.5mm alloy plate braced with 3mm ply
As can be seen in phots earlier the sponsons are attached with carbon rods that go right through the tub.

I will try to get a video this week. The only way I can film is to place the camera on the tailgate of my truck and hope to capture the boat on the water.

[ED66677]

The only way I can film is to place the camera on the tailgate of my truck and hope to capture the boat on the water

velcro it on a helmet

[nauti-tucu]

Hi:

velcro it on a helmet

Good idea!!!!

[785boats]

Hi there Simon.O.
I've recently joined this forum & I just stumbled across this thread.
Well done man.
Very interesting reading. It seems we both went through the same learning curve & basicaly came up with the same solutions & settings.
With mine however, I ended up leaving the fin on the front sponson. It's the only way mine will turn into the corner at full noise. It doesn't affect the prop in any way (at least that I can tell) & the rear can slide out a bit in the turn pivoting on the front fin. The fin is only about 15mm deep by 10mm wide & made from 0.6mm aluminium sharpened both front & rear.
I went for a twin rudder setup on mine. I used smaller & shorter rudders to offset the drag but they seem to keep the rear end tracking pretty straight.
I placed the C.O.G. at the C.O.L. (center of lift) of the wings on mine.
When I finaly put the brushless in the thing the wings would lift the rearsponsons off the water & the rudders would have no effect as they would be running in free air. She would then slew sideways & nose in. So I too ended up with the strut angled down to keep the sponsons on the water. Of course I put too much angle on it the first time & it blew over at top speed.
Anyhow, I just thought this info may help, or at least offer moral support, with the brilliant job you're doing.
Your build is the only other self designed & scratch built canard I've seen.
Keep at it.
Paul.

[Simon.O.]

Given the success I have had with reducing the frontal lift on the Rigger sponsons it is now time to address the lift issues that I have here with the Canard.

The main problem that I have is too much lift in the rear.
All strut adjustments have altered the handling and performance of the hull but one thing remains constant, the rear is too flighty
The internal layout does not allow me a lot of room for Cob changes and certainly not much room for ballast. I did try ballast in the Hydro as Jay suggested and this had a positive effect on handling.

I will narrow the sponsons on this as I did with the rigger as again this was designed for brushed power.

[Simon.O.]

O.k so the canard has been in for a nip and tuck to reduce the sponson lower surface area in an attempt to get the lift reduced.
I took 8mm of the width of the lower surface and put small air dams near the inlet to the lower wing surfaces.

I have run it with a few different strut settings and it is still very flighty in the rear which induces a near uncontrolable wobble that will often result in the boat laying upside down on the water.

There is only 2 deg of deadrise on these sponsons and about 5 deg AoA.
By contrast the rigger has less than 1 deg DR and 4deg AoA with a similar footprint but no wing area.

I will now rework the lower skins to increase DR and decrease AoA and see how it likes that.
After that i will have to look at reducing wing area or the lift effect that it produces.

I am running low on varnish by now with all the alterations that the balsa fleet is receiving.

[peells]

So why do you not change the angle of the wing (if it is in the rear) to an angle which will push down and cause the rear to be down lower in the water as it travels forward. and you might also try adding a little fin on each side of the rear at the back kind of like a surf board just enough to be in the water and maybe that will help with the shuddering as well. Just a thought as you have been trying to correct this for some time now, and believe me when I tell you I am not trying to offend at all just offer suggestions.

[Sneasle]

purrtttyyy boat you got there.

Now all we need is for Jet to finish up the small version. I'm first in line for one.

[peells]

yea it's not much of a shot of it though, but if you followed my link then you could see me run it, I am a crappy driver, yet it is still fun

[Simon.O.]

So why do you not change the angle of the wing (if it is in the rear) to an angle which will push down and cause the rear to be down lower in the water as it travels forward.

The rear wing is actually a skin top and bottom over the two carbon booms that go through the tub and into each sponson a bit like a rigger. To remove these skins and change the aerodynamic profile would be a major amount of work that I will leave as a last resort.

You might also try adding a little fin on each side of the rear at the back kind of like a surf board just enough to be in the water and maybe that will help with the shuddering as well.

I am not really clear on the fin idea that you have but I am very adverse to fins and other apendages if I can solve the problem another way. The motion in the rear is a roll effect in that the sponsons lift off the water one at a time in a very fast oscillation. This happened to the front of my rigger before I reduced the lift on that one.

Just a thought as you have been trying to correct this for some time now,

No kidding !!! This is a major challenge and I am loving it. There are a few out there that still think a Canard can be run well, I am one of them, and WIL get it to run smooth and fast just like my rigger.

Believe me when I tell you I am not trying to offend at all just offer suggestions.

No offence taken at all Peter, in fact the opposite. I value input from experienced boaters and innovative thinkers like yourself.

[peells]

I was just looking at your setup on #8 has this changed? I use a slight down angle on my strut,
I was noticing that your hull seems to be blocked off in the front maybe you could open it up and shift a little weight around, But you need some weight in the rear right? Do you have any videos of this boat running? I find them real helpful to study and watch what is going on. This problem may be as simple as a center of gravity thing, I know with my boat that comes into play because it is really picky about that, a little too much back and it runs real slow and a little too much forward and it is out of control, there is a fine line (the sweet spot if you will) and once that spot is found!!!! then you can have fun not to mention you have learned something, so in saying that do not change to many things at once because if you do and the boat starts working properly you may not know exactly which mod. fixed the problem,

[785boats]

Simon.
When mine was lifting off the water at high speed, I was thinking that an upturned flap on the trailing edge of the wings might create some down force. I never did try it though. I was just going to tape a strip of thin aluminium sheet along the trailing edges for testing purposes. Something that you could adjust the angle on. It might work or it might be a waste of time.
Maybe an air dam under the front of the wings like the ones they use on hydros might help. They spoil the airflow under the hull & reduce lift.
I ended up keeping mine on the water just by raising the prop angle to push the rear of the boat down.
Cheers.
Paul.

[Sneasle]

Ya know what might be interesting.. build one of these with a 3ch radio and actually build in some flaps at the back of the wings..

Only bad part is most 3-ch radio don't have a proportional 3rd channel. If you use 2.4, could do it with an airplane radio, would work out pretty cool I think.

[Simon.O.]

Right, I have found one of my biggest stumbling blocks so far, the hull is not symetrical.
On the board that I use to set my hulls for AoA and strut heights etc I have always had the Canard face transom left and set the sponson AoA from there.
Tonight while thinking of options to remove lift I discovered to my horror that the left sponson has under 4 deg of AoA and the right has over 5 deg.
This is not good.
How it happened is now spilt milk, so I have to work to correct it before this hull gets wet again.
Sister in law is here for a week and serious garden makeover work on order of the wife will make it difficult to do for 10 days.

I WILL get this Canard to work.