Balsafied Tiny Trainer

FAI-F1D

Free Flight Indoorist
Josh Bixler gave me a kit for the new Tiny Trainer that's coming out soon. I had a bunch of fun flying one of the prototypes when they were down here in January and was excited to get something like that in my fleet for small field flying.

Trouble is I can't leave well enough alone, and before I knew it, I was using the tail surfaces as patterns for balsa outlines. Next came a slimmed down balsa fuselage, and so on.

I built the wing with the razor thin AG03 airfoil, which required a webbed carbon spar...it's nice and strong, and very light. Power is an HXT 3000 kv outrunner driven by a 2s 370 on a 20A esc. The result is a sub-200 g model that glides very nicely. It's extremely maneuverable thanks to the large control surfaces and low inertia. It's docile as can be until you open the throttle.

It starts climbing around 1/4 throttle. Wide open it is absolutely ballistic--very, very ballistic, like 3:1 thrust:weight ratio ballistic. After a few flying sessions, I'm finally able to keep it pointed straight under power (expo and dual rates are not optional here). As a motor glider, it's superb. Doesn't have the glide performance of my larger birds, but that's the penalty of going small. It stays nice and docile in wind, does inverted flight, outside loops, vertical rolls, all the fun stuff. And it's stable enough in glide that my wife can fly it on low rates. :D

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Anyway, just wanted to show that once this model becomes available, you can form up a balsa version that's super fun. Josh has an ailerons mod on his as well. The great thing about this size is how cheap everything is. I've probably only got $50 worth of parts and materials in the entire model. Even with those tiny batteries, it's capable of well over 20 minutes in dead air (probably 25 if you're not doing any aerobatics). Bottom line, it's the perfect plane for me because it'll go anywhere and do everything you could ask for. I suspect the foam version, while not as high performing, will achieve the same reputation. Flite Test did a great job on their newest design, leaving me with an excellent platform for developing a high performance airplane.
 

Joker 53150

Mmmmmmm, balsa.
Mentor
That looks great! How do you go about picking your airfoil, and what makes one choice better/worse than another? I usually just build what the plans show and haven't gone to that level of changes yet.
 

FAI-F1D

Free Flight Indoorist
There is a method...you pick an airfoil that will match to your structure (balsa in this case, with no sheeting). AG03 will let you get away with this. If you go with an LDA airfoil, you need some sort of sheeted leading edge to preserve the extremely sensitive profile. For a slow flying model, you choose something more in the range of a simple undercambered foil, but that won't let you do inverted flight, and it kills wind penetration (except for LDA foils). Drela's foils give a good compromise of this wing penetration while still providing a fairly low sink rate, but they require as low a wingloading as possible.

Confused yet?
 

T-Richard

Active member
Looks very cool. Would you say it's a tough build? I only built guillows models and one big glider out of balsa so far so I am still a newbie with balsa.
 

pgerts

Old age member
Mentor
A picture of the different profiles and a sketch of the webbed carbon spar might have enlightened some?

I am in a project of scanning old model flying litterature - unfortunately everything i swedish.
I am amazed of how far they had come in profiles, Bernoulli and Reynold equations in the books från 1945 to 1947 i am just reading.
modellplankonstruktion.JPG
 

LocalHero

Member
You've piqued my curiosity. I have a bunch of Flite Test models, and I'm thinking about getting into balsa building. Would this be a good plane to learn balsa building techniques on, or would you recommend something else?
 

FAI-F1D

Free Flight Indoorist
You've piqued my curiosity. I have a bunch of Flite Test models, and I'm thinking about getting into balsa building. Would this be a good plane to learn balsa building techniques on, or would you recommend something else?

I'd recommend buying a simple kit first. There are a variety of great options out there. I particularly like Stevens Aero, Retro R/C, and Mountain Models. Retro's Wee Devil is particularly fun.

If you want to jump into the deep end with scratch building, try downloading a plan off Outerzone.
 

nhk750

Aviation Enthusiast
I just saw this thread from another link. Makes me ask why FT doesnt make some laser cut balsa kits like this? They have the equipment, the rights to the plans, and can make it happen. Their losing money every day they dont do this, at least my money...
 

SlingShot

Maneuvering With Purpose
I just saw this thread from another link. Makes me ask why FT doesnt make some laser cut balsa kits like this? They have the equipment, the rights to the plans, and can make it happen. Their losing money every day they dont do this, at least my money...

Ya know, as a corollary to the balsa, I remember when they flew the big gasser from the swap meet, it was mentioned that there would be more fuel content to be delivered.
 

TooJung2Die

Master member
Happy this thread was dug up. The Tiny Trainer was the first RC airplane I flew successfully after a RTF "beginner airplane" disaster that almost made me give up the hobby. I've done the balsa airplane to foam board conversion a few times. Flite Test foam board to balsa conversion is something that didn't occur to me. I don't currently have a Tiny Trainer in my airplane hanger. I'll have to rectify that oversight.