How to balance a canard model?
 

Building a plane with a canard on it and need way to balance. This plane has balance point 2 1/4 inches forward of wing leading. I have two questions about this problem.
One as this is a low wing model do I need to balance upside down ?
Two only way I can come up with is to use a threaded insert mounted on fuselage center line at balance point and screw an eyebolt into it, and hang on rope to balance. I think this will allow me to balance front to rear, and also wing tip to wing tip at same time. Question is does anyone out there have a BETTER IDEA or way to do balance a canard model? All Help will be greatly appreciated. Thank you for your time.

It sounds as if you know where the CG should be which is a good thing. I would build a single cradle that the model will fit into but allow movement. The balance inverted VS upright is really a non issue. The idea behind a bench CG setting is to get to a safe place to do your test flights and then adjust based on observations during your first flights.

Balance right side up, probably with a long eyebolt. Otherwise the plane will flip over on the long axis while you are trying to get the fore-aft balance worked out.
I hope your intended cg is correct. Too far back and it will crash, too far forward and you won't be able to get it to rotate on takeoff.

When I was balancing mine I have drilled small 3mm holes through the fuse to push the pin through. To make sure the CofG was correct I have build a smaller identical proto as a tester.
https://cimg9.ibsrv.net/gimg/www.rcu...dfab20a45c.jpg
Note the hole between the LE and TE of canard.
https://cimg0.ibsrv.net/gimg/www.rcu...a1fa538802.jpg
Added winglets for better stability.
https://cimg7.ibsrv.net/gimg/www.rcu...25cbc0e72e.jpg
CG test proto.
https://cimg8.ibsrv.net/gimg/www.rcu...431a6ec8ce.jpg
Sorting out the balance.
https://cimg9.ibsrv.net/gimg/www.rcu...3560c1f91e.jpg
Flying like a dream now.

Balance a canard.
 

Mr Frost, That is one sharp looking model. Your idea seems very easy to do, and to the point, and no problem to add to my build. Thanks for great answer. Ken C

Balance a canard.
 

Joseph I keep looking at your model, Is it a plans built or kit. I would like to have one.

It was scratch built from a plan by a friend quater century ago as a slope sorer. Never flown as such, just hanging on the wall untill I have seen it and got my hands on it, converting it to an EDF jet with some modifications few years back, the rest is a history, still flying it on 6S, now upgraded from an originally fitted marginal 70mm, to powerful 80mm Jet Fan set up.
https://cimg5.ibsrv.net/gimg/www.rcu...9ccacf464a.jpg
The way it was, built as a slope sorer.
https://cimg4.ibsrv.net/gimg/www.rcu...fd11b493f3.jpg
My conversion to an EDF jet power.
https://cimg9.ibsrv.net/gimg/www.rcu...458192906b.jpg
In action.

Wild looking bird.
 

Thanks for the reply. You should take the time to draw up plans for your most unusual model. I would buy them if at a reasonable price. If you could draw up a foam model at a reduced scale, I bet you could find a market for it. At very least maybe sell construction article to model magazine. Well just some thoughts on a very neat looking plane I would love to try. Ken c.

I'm sure if you do some search you could come up with the original plans for this model, they must be laing somwhere. I never use plans, I rather experiment to make it or brake it, LOL.

This was part one of my conversion some years ago for few magz.

And now for something different –------- the "X-29" slope soarer conversion to an EDF jet.
Some months back while I was on a on a flying trip and visiting an aero modeller friend, I noticed that hanging on his wall was a somewhat unconventional balsa air frame with unusual wings, which were swept forward. He told me that he built it a quarter century ago from some magazine plans and intended it to be a slope soarer. As time passed he moved into more advanced jet powered models and he never managed to fully complete or fly it. Being curious, I took it off the wall and the first thing that really surprised me was the lightness for its size. “Nice”, I said, adding that would be interesting to make it into an EDF jet, hang it back on the wall and leave it at that.
A few months later I thought, “ Why not?” and so on my next visit to him I traded afew bits and pieces for it, assuring him I'd let him fly it if I succeeded with it. Back at home, it went straight on to my work bench. I stood there for awhile scratching my head, wondering where to start. Using an intended 90mm EDF unit was out of the question. It was far too large for this very sleek fuselage-- so a 70mm unit had to do the job. Pulling a few old units out of my junk box and temporarily fitting one to the aproximate area where it was going to be mounted, together with adding a large lipo battery to the nose, gave me some idea about the balance. My guessing of the CofGposition was correctly confirmed when I removed the canopy and there it was –----a marker on the side of the inner fuse. This was great news as there was no other reference on this construction. The position of the power unit with the thrust tube was marked and the next job was to remove the large rudder with part of the rear fuselage. The areo modeller friend would have been horrified had he seen me with the Stanley knife just cutting the soft balsa wood by free hand and throwing the whole rudder assembly into the trash bin.
While I was at it I also removed both elevator tabs as they were too small for my liking. All internal fuselage formers were also removed . This would restrict the placement of my new power system, with the out of date aileron and elevator/cannard push rods to be later replaced with aileron servos fitted into each wing for precise control and separate servos to operate the elevators and cannards for proportional mixing.
I decided to redesign the elevator stabs to be more conventional, while at the same time extending the fuselage lenght by some 15 centimeters for more stability and installing twin "V" shape fixed rudder fins on each side of the power units thrust tube. To minimize the weight I used light ply,balsa,depron reinforced with carbon fibre rods. Power unit mounting formers were well anchored to the fuselage with initial 3.5 degree set up thrust. To keep the all up weight to minimum I was hoping to use a 4S/2800 (16V), 70mm fan with 45amp ESC but had some doubts if the power would be sufficient for this size model, but with the intention of later upgrading to a more powerful 6S/4000 (24V).
The whole airframe was gradually primed, painted and fitted out for few static test runs. At close to drawing 40amp current the 2800mAh batteries couldn't handle it, so larger 4000 packs would have to be used and, unfortunately, adding extra weight.Thrust figures were marginal but flyable after a few taxi test runs were performed on very simple fixed landing gear fitted with steerable nose gear. Unfortunatelly, the cheap wheels I used only lasted for a few runs along the back lane road and had to be replaced with better quality alloy hub ones. Slightly more robust wire legs were also fitted.
Now with the project just about complete with the reconstruction ready to fly it, the big worry came about setting the correct control throws and the mixing of cannards to elevator. I didn't get any positive replies to my prior enquiries on this original project built so many years ago and having only experienced flying a few models of my own designs with fixed cannards, my initial idea was to set about half the movement of cannards to elevator. I knew it would be a matter of trial and error with this totally redesigned project, especially as the power unit fitted to the top of the frame might create all sorts of unknown problems.
So, to be rather safer than sorry I thought of my old trick of building a smaller and simpler glider version which would give me some idea of what I might have to deal with. With the help of my calculator and my drafting skills I drew and cut out identical three quarter size shapes of the frame using 3mm sheet of foam core. By making use of carbon fibre and ply wood I took out some of the flex and then fitted it out with the same controls. By positioning the small NMHi battery I marked the balance point.
Like all good aero modellers time is too precious to waste and off I went to thenearest hill to do some hand launching. After some minor adjustments I was quite pleased with the stable glide but found the flight distance rather short due to the height of the hill, being only some 50 metres in altitude. Next day, hoping to do some wind soaring and with a fairly decent wind I took it to my friend's farm as it had a huge hill and deep gully below. At only 500 grams AUW I thought I would have a great chance and after a number of launchings down the gully and into the wind the model flew well under my full command providing the nose was pointed down to keep its speed but as soon as I raised the nose to a slightly positive angle the plane stalled and became uncontrolable. My first thought was that a slope soarer could certainly not be such a weird jet design but I was satisfied with the glide controls while keeping up its speed.
Jets need power. While driving back home I came up with the idea of fitting it with the smallest fan I had in stock. Wading through my junk box and spare parts I found a very light outrunner motot with an old 70mm fan I had upgraded many years ago in a little Sea Vixen EDF model The idea of powering this mock up set the adrenilin going, so it was full speed ahead in rebuilding the frame and fitting it up. It was still pretty light for its size at just at about one kilogram with a 4S/3000mah battery. At 600 watts it would be good enough to move this prototype.
The next day after flying at my home club I pulled this “thing” out to show off to fellow modellers and decided to check the range as I was using 10ch. 36 meg. frequency. I was rather shocked when I had a total black out at only some 60-70 metres under full stick. I was certainly surprised because I still fly numerous models even at a lot higher voltage on this frequency while using top brands –----not FM, but PCM 9 to 12ch. receivers. Back on the bench I thought I'd reposition a few things and if the problem wasn't fixed I'd use 2.4 GHz. Unfortunately with very limited fuselage space I had my 45A/ESC with the external voltage regulator, receiver, battery and all the power leads just centimetres apart which was creating all the interference. Upgrading the ESC to programmable 80A with an inbuilt BEC and moving the RX all the way to the nose which was almost 50cm away rectified all the problems after further range checks.
Absolutely great! Couldn't wait for the next day but this time with a helper to launch it for me. Off it went with full power into this spectacular back drop view, all the time holding a level flight path while increasing its speed .However I noticed straight after the launch quite a dramatic flexing of the wing tips under the load. While making the turn towards down the wind leg it seemed as if I had lost my elevator authority andthe plane nose-dived into the ground. No damage was done except for a slight bending of one wing tip. It was pretty lucky –--- it could have ended up being a lot worse. The wing tips had to be stiffened by adding extra carbon spars . The next day after that first successful launch I performed it by myself.
Stay tuned –-- to be continued.
https://cimg0.ibsrv.net/gimg/www.rcu...e3b0f8da50.jpg

Joseph, well we are waiting for next installment. Ken C.

Continuation for your enjoyment.

Continuation-Part 2,Finale-Maidens.

Back to the big hill full of confidence after the previous successful launch, this time I fitted video camera
to my helmet to analize the flight. The Easterly wind was close to 20km/h, slightly higher than I would like for
test flying but it's only a prototype so I thought I either make it or brake it. Off it went again with powerful
throw this time launching it on my own directly into the wind over the huge gully bellow. And, what a "difference",
after the strengthening of the wing tips. All the nervousness dissapeared moments after gaining the full control over,
and the first circuit. These are the moments what this great hobby is all about. Little bit of a battle into the wind
with this rather inefficient fan combo but down the wind she was moving very nicely. I noticed aileron controls
being very touche, probably still due to some wing tip flexing during my turns, but most importantly the pitch control
worked perfect after correct canard/elevator mix and the angle of efflux. While enjoying my flight I heard the sound
of motor bike and there he was, the farm owner on his quad paid me a visit after seeing this weird looking jet flying
over. Just about ready to land, I glided it down into the moderate wind under the full command by stalling it few inches
above the grass to full stop only some 20 feet in front of myself. The farmer was impressed, not to mention my own
satisfaction. Couple more flights with another high performance model I brought along really made my day.
Next few days after some more adjustments I did numerous flights including few basic aerobatic manuevers with
video footage analysis back at home. Back on the bench in my hangar I went strait to my original to reset all my
controls, ballance and the thrust tube based on this prototype. There were few other improvements to the frame
like stiffening some flexing in my elevator stabs to eliminate possibility of flatter and ading some servo protection
fins to the bottom of the fuselage. Final checks and next day with helper friend I have decided to take it to the beach
at very low tide to do the full range check and perhaps condition permitting to do couple of strait low level flight
checks. Unfortunatelly, late afternoon with the lowest tide the wind was up to over 30km/h. The range check of all
controls at some 200 meters on full power was all positive so I went ahead despite "not to do it" suggestions by my helper.
The wind was screeming!, but at least this time nicely along the beach comming from the North. Taking extra precautions
I did few taxi runs up and down the beach strip increasing the power gradually but on the next one into the head wind
I increased my throttle to full power being anxious to see the model at least to lift off few inches. To my surprise it did,
but more like 3 feet so instantly reducing the power it dropped the nose but quickly regain full control by ading more
elevator. "Wonderfull", first joey's hop some 15-20 meters in these attrociest conditions, but giving me another boost
of confidence. All caught on the film by my friend's camera on his hat was later analyzed. Not fully satisfied with the
accellaration speed of my 4S power set up, next day I spent testing and comparing the static thrust, current draw,
wattage and wing loadings of this and few of my similar size models. New decission was made at the expence of ading
more weight, but by upgrade to 6S my power went to over 300 Watts per pound compared to my intended lighter 4S set up
in low 200's. Some alternation had to be made to fit this heavier fan unit with the new thrust tube
rolled out. With the help of my program card the speed controler was also reset to new values to optimize performance.

This time fitted with the large 4250mA, 25 volt battery the CofG was still spot on and after the static run while holding
model in hands vertically, it just about held its AUW at 2400grams confirming this thing will fly. Couldn't wait for the next session to test it with the intention to do it again at the beach smooth hard pack sand rather than off the bumpy grass where you can get premature hops with light wing loaded models. The next opportunity at low tide the wind was
unfortunately blowing 90 degrees accross the strip, but reasonably low at only 10-15km/h, placing the model some
70 meters from my standing position I have gradually applied full power noticing dramatic difference in accelleration,
model rotating just in front of my position to some 6 feet height. Imediatelly reducing throttle and gliding it under
full pitch control model drifted slightly to the right due to the cross wind and no rudder function, clipping the softer dry
part of the beach with the right wing tip. Horrified, seeing my model to pancake "360" at still pretty high speed and comming to a sudden stop I run some 100 meters expecting the worse, fuselage in half after the impact. Luckilly no such a bad luck thanks to the dry soft beach sand. Picking up the model with not even bend landing gear, placing it back on the hard packed strip this time closer to the waters edge I had another go this time being more careful rotating lower to only some 3 feet and holding the level flight lot longer close to 100 meters in length and touching down gently as a ballerina.

"This is it",
all I wanted to see before my full maiden flight, almost tempted to take off again a go around but common sense told me, be patient and lets do it rather at the local flying field for safety, just in case. The surf in such a close proximity
is not a best place to do the full test flight, still with out knowing how will it respond during turns. Packing it up and
walking back home through the reserve with the pride. Next day, visiting one of my clubs hoping to fly it, the weather
conditions weren't to my full liking and just a few days to Christmas, it got even worse. Horrendous winds and when
they stopped the rain came down in buckets. Some Sydney suburbs experienced some of the windiest conditions recorded
at well over 200 kilometers per hour and declared as disaster zone unfortunately also affecting this part of the coast.
Nevertheless, as all the bad things have to stop the sun came back shining again so I have managed to cut the grass strip
after all the deluge but the wind was still too high at well over 30km'h, so there was more delys for my maiden.
After my daily check of the weather forecast the first opportunity came on the New Year's Day, everything ready in my
van I headed the first thing in the morning to the flying field, conditions still not favored with moderate wind some 45 degrees across the strip I have decided to go for it. With fully charged batteries I did my final checks of all controls, placing the model at the end of the strip and gradually increased the throttle to full pover this time off the grass runway.

After few little bumps and hops it cleared the ground just in front of me after some 60 meter run and steadilly climbed
to safe height just to clear trees on the southern end of the strip. First gentle anticlock wise turn was very stable but after few circuits I noticed my aileron controls pretty sensitive so further travel reductions will follow. The pitch controls were just about perfect at any power setting which was my main concern prior to the flight. Speed of the model wasn't as fast as I expected probably due to this weird swepped forward wing design and rather large frame for 70 mm power unit, but on other hand
very realistic scale-wise for its size. Landing in the cross wind was little challenging with out any rudder function but after few abrupt corrections I have managed to bring it down nice and gentle on this narrow only 4.5m wide cut grass portion of the strip. Keeping the flight time to minimum at only 2.5 minutes, the battery check comfirmed the future flight sessions up to 5 minutes on mix throttle. Absolutelly delighted with the successful maiden I enjoyed the rest of the morning flying few other EDFs I brought along and the first thing on my return was contacting my friend, the original builder of this unique model with the good news.

Happy and Safe flying, Joseph Frost.

Add on, further mods were done at later stage by upgrading the slightly marginal 70mm fan unit to hotter 80mm Jet Fan, also ESC upgraded with some intake air scoops to keep it cool.


https://cimg0.ibsrv.net/gimg/www.rcu...64a66a009b.jpg

That is one interesting plane.
 

Glad you worked out a very nifty and very unusual model to fly. I t will turn a few heads at the field. Good luck with it in future. Thanks for the whole story. Ken C.

canard balance
 

Joseph, I have started a build log on RCGroups forms - balsa builders. Again I thank you for simple answer to my problem. I have incorporated in my build and will give you credit for it. Ken C.

Balancing a canard model.
 

Joseph, I have a build log on RCGroups forms, aircraft-misc. , balsa builders. On page four you will find I gave you all the credit for your idea on how balance my canard model. Hope you will enjoy reading my build thread. Ken C.

Work like this, motivates me to sit down and glue on cap strips on the last section of my wing to an incomplete kit I started 2 years ago...see about mounting the engine in 2023.

One of my latest project, converting decade old well flown, giant turbine powered Delta, entirely constructed from 6mm Depron sheets with some sandwiched carbon fiber reinforcements, now to EDF power, promped me to add on fixed canards to the nose with some winglets added to the delta wing tips, to slightly reduce the wing load. Unfortunately 2 kilo heavier thanks to E-power, with huge 3-4 kilos of more static thrust, can come handy on full bursts if needed compare to sluggish, slow spool up responce of turbine power.
To make sure my new mods to the frame won't create some havoc on its maiden flight I have created smaller identical shape proto (40% size) to confirm CofG for the piece of mind.
https://cimg1.ibsrv.net/gimg/www.rcu...02ab2038e0.jpg
From this, to -
https://cimg6.ibsrv.net/gimg/www.rcu...465222130a.jpg
- this.
https://cimg4.ibsrv.net/gimg/www.rcu...5e9f7253a6.jpg
CG test proto in making.
https://cimg8.ibsrv.net/gimg/www.rcu...c7fd3d9d06.jpg
Sling shoot trials.
https://cimg9.ibsrv.net/gimg/www.rcu...1fe5f8559f.jpg
Heavy wing loaded with 3-4 kilos of batteries.

Balanceing a canard.
 

Now that is one sweet model. "Wow" is the first thing that came to my mind when I took a look at your creation. That is one wild looking plane. Love your color scheme. I do have one question for you, if you made it from foam and power it with a turbine engine , do you not worry about exhaust burning or melting plane ?. In air I am sure things stay cool, but when you land the heat from turbine could cause problems with no air flow to cool it. I would think the same would be true when you start engine before takeoff. Just some random thoughts bouncing around my brain.
I hope you are watching my build log. Ken C.

Thanks Mate, so far after building three turbine powered foamys none of them melted. Important thing is to always starting with the model facing the wind so if you have hot start the fire blows back, only ones while starting wrong way with bit of hot start one of my Depron rudder fin partially deformed in my smaller 'Wren44' one, but as a precaution nowdays I use metal "V' shape cover at the rear while starting. Otherwise, no problems at all with the heat that blows backwards. After landing each turbine has a cooling procedure programed in.
Internally mounted power units in foamies, that's another story, I would never build one of those!
BTW, I'm out of RCG for good so I don't follow anything there anymore!
https://cimg4.ibsrv.net/gimg/www.rcu...b5f99d4219.jpg
I use protection cover during starts, just in case of hot start to protect the Rudd. fins.
https://cimg9.ibsrv.net/gimg/www.rcu...89f7836c3e.jpg
This one has been running for over a decade.

Engine heat problem?
 

Heat damage to model, looks like you have it all under control and well thought out. That is one good looking young lady in second picture. I am trying to sent you pictures of my canard. Not sure this is going to work. My computer skills suck. Please let me know if it works out. There should be two pictures. Ken C.
https://cimg1.ibsrv.net/gimg/www.rcu...a7384d7e27.jpg
Better shot of holographic pattern. I used gold and red for checkerboard on canard. Same thing on wing, but bigger.

This is my Scat Twin 40. almost finished, just needs a canopy. I used holographic material to do checkerboard and trim.

That will glow in the sunlight, nice. I use on number of my foamies gold or silver leif, even used copper on one of the "Yak-130" for a variety, they glow nicely under sunny sky.
Piddly job to apply especially 24 kt. gold, you got to hold your breath not to blow it away while laying it down. LOL.
https://cimg3.ibsrv.net/gimg/www.rcu...98e7bd9461.jpg
"Golden Meduza" glow.
https://cimg4.ibsrv.net/gimg/www.rcu...0d0ce2c0a5.jpg
https://cimg5.ibsrv.net/gimg/www.rcu...85e15384fc.jpg
Copperhead that bites on occassions. LOL.

Canards that shine brightly.
 

Wow, you do some great work. I have no idea how you put on gold, but looks very time intensive job. Great results with it. Me I take the easy way out and use holographic film, some are iron on and others are self stick. I find these films at local big box craft store near me. I like your work and your planes look out of sight. Keep it up, and good luck on all your future endeavors. Ken C.

Canard pictures.
 

I am trying to send finished pictures of my Scat Twin 40.
https://cimg1.ibsrv.net/gimg/www.rcu...63fff07b0a.jpg

ME and my model Scat Twin 40 at field.

Rather interesting combo, let us know how it goes.
I have finaly made a trip to test fly my modified "Magenta" off the sealed strip, now as an EDF fitted with canards and winglet extentions, running immaculate, thanks to my trials with the smaller made up test proto.
Awesome power, moving pretty nice for a12 kg mass at 50-75% stick, bit of head wind would come handy for landing, as my maiden was in dead calm and pretty long, almost running out of strip. LOL.
https://cimg8.ibsrv.net/gimg/www.rcu...78bf7fc2d7.jpg
I like it.

Canard
 

I would love to see your plane on video, bet it would be a wild sight. Good luck in all your future endeavors. Ken C.

My only concern prior to maiden was the effect of power unit thrust line, took only some 40m to lift off the 12 kilo mass, the move of my landing gear 12cm closer to the CG also helped. More than pleased with the conversion, so much easier, just plug it in and off you go rather than messing up with the turbine compexity and filthy smelly kero.
(Magenta re-maiden as an EDF)