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Tiny Trainer based Canard anyone?

Hai-Lee

Old and Bold RC PILOT
#1
I have built and flown 3 versions of a canard based upon the original FT Tiny Trainer and do not have the facilities to provide the requirements for a full FT article.

Model Aircraft July 2016-10.jpg

If anyone wishes to build and experiment with the designs wishing to eventually publish please advise as I will gladly pass to you the design information around which you can experiment.

The designs range from a 3 channel 2 servo unit as shown above to a full house 4 channel design.

My own next step is to attempt to reduce weight by using a detachable above wing power pylon to bring the weight forward and reduce the nose weight added in the initial design.

Flying is great!!! Crashing is just the inevitable consequence.

Bob
 

rockyboy

Skill Collector
Mentor
#2
Very cool! I'd love to see the design info you've collected. I have 3 tiny trainer wings and one very wrinkled tiny trainer fuselage. It would be great to find another use for the wings!

Also, what are you missing to finish up an article? Perhaps myself (or someone else here) can help fill in the blanks so you can get your first article published?
 

Hai-Lee

Old and Bold RC PILOT
#3
The abilities I am missing to do an article is photography, video recording and a decent CAD program. The photograph posted was taken by a passing spectator who took s series of my test flights that particular flying day.

I had written a draft text for the article but am missing too much to complete said article. I have attached the text which contains the draft. My photography capability is restricted to a somewhat dated and poor quality cell phone.

DRAFT TEXT:

Josh Bixler's Tiny Trainer is a great and inexpensive trainer which is perfect at a time when crashes are most prevalent, when beginning to learn to fly. There is something for almost everyone here. It is really simple and fun to build. You can have a multitude of different configurations available if you built each version of wing, and nose.
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The Tiny trainer is really a component airplane. The airplane is built in different sections (forward section, power pod, fuselage section and wing) Once the components are constructed, it is just a matter of selecting the parts you want to use and mating them using BBQ skewers and rubber bands. Up till now you either ended up with a very easy to fly 3 channel trainer, a slightly zippier 4 channel sport/trainer, or an entry level slope soarer, all with the choice of tractor or pusher setup, (if you built the Bixler type nose). Performance of all versions can vary markedly depending on motor/ propeller combination used and the voltage of your battery pack. (2 cell or 3 cell)

I have built all of the various versions out of 5mm foamboard and 3mm foamboard. Those whom I teach to fly, start on a badly beaten up basic 3 channel tiny trainer until they commit and build their own.
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If you are bored with it or you are after something different having built, flown, and retired your own tiny trainer. What about a tiny canard? With the number of the Tiny Trainers I have built and helped build, along with the crashes I have had as well as observed, I have a number of spare bits and pieces on hand, (mostly), from my students. All students are taught to fly build and repair at no charge. They do need to commit and build their own.

So whilst I love the original design I wanted something to increase my own flight experiences and I thought that the only versions not touched upon were a canard design and an Autogyro. I had a good Aileron wing, a "V" tail mixer from an old flying wing glider, a bucket full of pusher propellers and a dodgy 3 channel receiver, (as I discovered later).
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With that, I took on the task of juggling the existing pieces of the design to turn the Tiny Trainer into a Tiny Canard! The classic "What if" led rapidly to 2 separate versions, The first version used fixed vertical fins and a fixed foreplane, (at 8 Degrees). The second version added additional servos and a "Y" harness which allowed for a variable foreplane, (Elevator), and a pair of rudders. A third version, designed specifically to reduce the weight with a pylon power pod, might be supplied at a later date. For this article I made new tiny trainer pieces out of 5mm foamboard, (A foamboard crease really looks bad when photographed). My original prototype suffered a series of "Out of Control" episodes until I realised that I was using a faulty receiver, Duh!!

Just like everything else with the Tiny Trainer, converting it to a canard was relatively easy. The basis of what I did is that I simply took the aileron wing, "V" tail mixer, the Tractor nose, the glider nose and joined the noses together with a new rectangular fuselage section, 650mm long, and also new set of tail feathers. The tractor propeller was swapped out for a pusher propeller and the tail feathers were fitted to their new locations.

The tail feathers were basically the original design, modified by cutting the original horizontal stabiliser in half and fitting two vertical stabilisers making the rudder lengths 25mm to clear the propeller arc. The vertical stabilisers are glued to the sides of the power pod nose and have the power pod mounting skewers passing through them. Refer to the photographs.
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There is no plan to be supplied, or really needed, unless it is required by a large number of people. With my photographs and the original plans and I am confident you will figure it out.

This is not the perfect design and I encourage others to tinker with the design to improve it. The only guarantee I give is that it will fly and it really attracts attention!!!!!
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Here is a photo of the variable foreplane installation details And the angle of the foreplane is 6 degrees on my prototype. The foreplanes, (fixed and variable), use 2 Bamboo Skewers which also secure the glider nose to the fuselage. the skewers are not glued in place unless you will not need to remove or replace them.

I usually cover the foamboard with packing tape, unless it is a short life prototype, for strength and water resistance. Rubbing the tape into the foamboard can greatly improve adhesion and hence strength. Make you use bright colours as this one can really hoot and the different configuration can be a little confusing to those not used to it!

Pre Flight Setup

Balance point is important! On the fixed foreplane prototype the CG point was 55mm forward of the wing leading edge. Feel free to vary it around this point but if you bring it too close to the wing the plane will just stand on its tail and crash tail first. With the CG set as recommended the fixed foreplane version's nose can suddenly rear up in strong wind turbulence but always remains fully recoverable. It is fun to fly and I use it to map air pockets and other turbulence for my trainee pilots before lessons on windy days.

The long moment from CG to foreplane makes the design sensitive to sudden wind speed changes that are not shared between wing and foreplane. Nose weights are necessary because of my use of the original tractor type nose and also the only battery I had to hand, which would fit was from my Wingnetic speed wing, (850mA 3S). Hence the long centre fuselage section. My students buy their own batteries.

The aileron/flaperon directions are as standard in roll control and the elevator function appears reversed in that it should cause the both of the ailerons/flaperons to rise when pitch up is required. When using the variable foreplane it will need to lower in order to pitch the plane upwards, (opposite that of the flaperons).

Initially use minimum throw on the variable foreplane, (if used), as the moment is long and the plane will fly with the foreplane fixed in position. The remainder of the the control surfaces use the same settings as the original tiny trainer design.
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Flying/Soaring

I usually launch with a strong throw towards the horizon and into the wind at full throttle, remember that to pitch upwards the tail must drop, (pronounced when using the fixed foreplane), and grounding the tail hard can end your flight before it has begun.

Establish level flight and then begin a gentle climb. Ease back the throttle a little during the climb and once at a safe altitude adjust trims for stable level flight. Non-aerobatic flight is smooth and delightful but when it comes to loops they are very difficult on the fixed foreplane version due to the rapid speed loss on pitch up. Sharp banked turns are rapid with the tail skidding around at a great speed.

Landing

My preferred way to land is to setup a nice long final into the wind with the engine power reduced to minimum once you are on final. When close to the ground do not give any sudden large pitch inputs with minimum throttle as tail strikes are quite possible. She will generally set up a nice smooth slow glide to the ground. To plant the plane in a hurry, to avoid overshooting, sudden application of coarse elevator can plant the nose or tail firmly on the ground and a landing ensues, albeit a rough one!.

Please note. the propeller wash is not blown across any control surfaces so flying speed must be maintained iif you want to maintain control. Manouver can be erratic at very low air speed. To the veteran tiny trainer pilot this model will seem very strange and possibly even amazing. You might quickly rediscover your old "What If?" and see a myriad of development models and possibilities.

Other Information

The Hobby King 2205 C motor coupled to a 6x4.5/5 propeller is a beautiful combination on this airplane. However, I think many other motors and props will probably work as well. Use what you've got but the canard, (As shown herein), is a little heavy so it likes a bit of power.

The battery I used is a Zippy 850mah 3 cell compact 25C. Fits just right.

I use a HK 12amp esc and TG9z, (9 gram), servos all the way around on both versions.

If you like to tinker and fly things a little out of the norm then give it a go. If you have an old tiny trainer laying around try this a relive the days when the design was new, "Thank You!", Josh Bixler for the original design, many people owe their RC flying skills to a start in the tiny trainer design.

I hope you enjoy this as it flies so differently it raised my interest (and heart rate) and actually is one of my few aircraft that has the "Retail" fliers amazed or spellbound.

Bob

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Hai-Lee

Old and Bold RC PILOT
#4
Rockyboy,

You mentioned that you had a number of spare wings for the TT. Perhaps you could consider something even more radical based upon the original TT.

What about a 3 channel tandem wing push/pull aircraft? Simple wiring! only difficulty or effort required is the physical removal and flipping of the servos in one of the wings so that they operate in the opposite direction. After that is done the diagonally opposite servos are linked with a "Y" harnesses and then either directly into the receiver or if using an external mixer directly into the 2 output ports of the mixer.

The Esc's are wired the same as any other twin engine aircraft and a larger battery can be mounted centrally to achieve the required CG

The motors are of course tractor in the front and pusher at the rear. Sounds like something I will add to my to do list:black_eyed:

Sounds fast as well with a low landing speed. Thank you for the idea!!
 

rockyboy

Skill Collector
Mentor
#6
Great draft write-up!

I happen to have a spare glider nose hanging around too, so I think I'm going to try building one from your description to test out the instructions.

I think all I need to do is build the fuselage, cut new vertical & horizontal stabilizers, and put it all together with my other existing pieces. I'll take some pictures along the way and post for you to use in the article if you like. If weather permits, I plan to hit the field this weekend and might be able to get some maiden flight video for you too. :)

Thanks!
 

rockyboy

Skill Collector
Mentor
#7
Rockyboy,
What about a 3 channel tandem wing push/pull aircraft?
Hmm... that sounds pretty wacky... :)

Two of the existing wings I have are the dihedral ones though - only one of my current set has ailerons. So I'm going to get working on the canard version first and wait to hear from you on the tandem wing :)

From my experience building and researching the Flying Flea tandem design, having the wings be "out of line" from each other will probably be helpful. i.e. not having them both mounted to the top of the fuse, but one on the top and one on the bottom. Seems turbulence and lift are both impacted a good bit if the wings are directly in line with each other.
 

Hai-Lee

Old and Bold RC PILOT
#8
Your comments about the Flying Flea wing geometry is well noted as I know of the design and its historical stability issues.

I am wanting to keep it as simple as possible and so I will try to use horizontal separation and wing incidence to compensate for the net negative angle of incidence of the disturbed airflow over the rear wing.

Will keep you advised.

As for the canard just be careful of travel limits of the servos when applying full control inputs When a servo reaches its travel limit adding extra elevator or aileron input does nothing.

Also note the CG position or you will be trying to fly lame duck
here is a flying profile shot Model Aircraft July 2016-16.jpg

Have fun and "May all your landings be survivable".
 

rockyboy

Skill Collector
Mentor
#9
Excited about this! :)

I think I'm going to try the fixed canard first, and then move on to the movable one. You mention both 6 degree and 8 degree incidence angles in your tests - were there significant performance differences between them?

And for the moveable canard, did you build it with the entire surface moving, or just the rear "elevator" flap? And I wonder what the roll rate would be if there were two servos driving the canard that could be coupled with the ailerons.... hmm... this is a neat platform for experimentation!
 

Hai-Lee

Old and Bold RC PILOT
#10
The foreplanes were both fixed using 2 skewers through the fuselage. The variable foreplane was mounted at 6 Degrees just because I was worried about too much about stalling at high control input but this did not eventuate. The variable foreplane flies with a considerable amount of down trim on my prototype so if you use the 8 degrees it should be much better.

I used the same area of elevator as per the original TT elevator and I used the front mounting skewer through the forward original nose mounting hole the second skewer was fitted just in front of the elevator hinge line through the fuselage to set the incidence angle.

To link the 2 surfaces I used 2 of the largest commercial control horns that I had and linked them over the top of the fuselage with a length of tight fitting music wire.

In the approximate centre of the wire I fitted an aileron control rod connection normally used when using a single servo to control both ailerons.

The servo I fitted into the top of the new fuselage section just behind the nose section

The rudders when fitted have the control horns mounted on the insides of the surfaces and connect directly to an above fuselage servo using a push-pull set of push rods.
 

rockyboy

Skill Collector
Mentor
#12
A Tiny Trainer (mostly mushed up) is reborn as a Tiny Canard! Thanks Hai-Lee!

Fixed canard at 8 degrees at the moment - will see how it flies this weekend and think about changing out for variable canards later.

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Hai-Lee

Old and Bold RC PILOT
#13
WOW!

You work really fast and it looks terrific.

Just remember the CG point and it will fly until its unusual handling leads to a little confusion and a trip to the earth.

Take it gentle and have a great flight. Wear earmuffs when flying it so you do not get distracted by the gasps and other noises from the gallery.

Thank you in advance:applause:
 

rockyboy

Skill Collector
Mentor
#16
I did make it out to the field on Sunday morning, and while I had a great day the Tiny Canard did not.

As I was doing a final radio check in the pits, making sure the control surfaces wiggled the right direction, I brought up the throttle and instead of spinning, the motor just stuttered a couple times and stopped. I had over two dozen flights on this power pod, but it just wouldn't go. So I throttled up and down a couple times, but still nothing but a stutter of motor movement. Then the smoke starting coming out.

I yanked the battery connector quickly, but the the smoke was still rising, and I could see flames inside the power pod. It sputtered out after a few minutes (burning foam smells bad, but doesn't want to stay burning) and then started taking things apart to survey the damage.

Surprisingly, the fuselage is in good shape still - but the power pod isn't. All of the electrical connectors are just fine. The ESC is a total loss - it got so hot that the solder melted and released the motor lead wires. And I don't really trust the motor now, so it's going into the junk drawer too.

Luckily I do have a 2205 1600kv and 20amp esc on hand to go back into the Tiny Canard, and as of last night it's almost back together. The down side is I won't be able to get back to the field for at least two weeks - heading on holiday with the family in a couple days.

I think the new (slightly more powerful) motor and ESC will do even better, but it will be a little while before I can check. :(
 

wilmracer

I build things that fly (sometimes)
Mentor
#17
Saw this at the field yesterday. Looks VERY cool and I'm sorry we didn't get to see it fly. I'm sure Rockyboy will get it squared away. Definitely sucks about the power pod and ESC/motor loss.
 

rockyboy

Skill Collector
Mentor
#18
Saw this at the field yesterday. Looks VERY cool and I'm sorry we didn't get to see it fly. I'm sure Rockyboy will get it squared away. Definitely sucks about the power pod and ESC/motor loss.
Thanks! I'm way more bummed out about not being able to maiden the plane yet than the hardware. It was just a cheap hobby king $15 motor and a 10amp esc, but it was my first power pod getting back into RC last summer. :)
 

Hai-Lee

Old and Bold RC PILOT
#19
A bad weekend for us both as saturday here was perfect but almost no one turned up and Sunday when all the fliers turned up got so windy that we were all busy trying to stop the planes in the pit area from leaving on the own accord.

My photographer is back on deck finally, (I hope), and I hope to provide flying pics of the variable foreplane version in flight.

One of the fellow fliers here stated that the background on the pics looked too clean almost like fakes. So I looked for a harder to fake pic and found the first launch photo with a bit of background detail.

Model Aircraft July 2016-6.jpg

The old bloke is me sadly.

As for the need for parts I am waiting on my hobbyking order delivery.

The only fire I have ever had was caused by the motor mounting screws eventually shorting out the ESC circuit board and a lot of smoke and heat ensued.

Replaced the ESC and all was fine after I altered the mounting of the motor.

Hope to add some more pics next week.
 

rockyboy

Skill Collector
Mentor
#20
Finally got this out to the field for a maiden flight with a new esc and motor. There were some young'uns around to help run the camera while waiting in the buddy box line, and they even recognized the Tiny Trainer elements in the design. :)

On the down side, I'm not sure if the new motor I put in had enough power - as you can see from the video, it really wanted to go vertical and didn't have the 'oomph' for that. But I think the biggest problem is being very tail heavy - even with the battery as far forward in the nose as possible (and a long batter lead). I'm planning to put in a forward servo and canard control surfaces to add some more functional ballast up front next.