Tiny Trainer will not fly

[hiawatha]

Hey Guys,

The Tiny Trainer is my first RC plane and I cannot get it to fly like the youtube videos show. I'm running a speed build kit with stock power-pack A. My first 17 flights with this craft have been an absolute disaster and I don't even have enough information to make any intelligent next-step choices, and I don't know how to debug this. Here is what happened:

1. Launched the tiny trainer. It went nose down right away and destroyed the propeller
2. Replaced prop, pushed electronics toward the tail. After launch, it went straight down into the ground and destroyed the second propeller
3. Went to hobby store and replaced stock propeller with one slightly larger, a 7x5. Realizing it was probably nose-heavy, I velcroed the heavy hardware inside the body so nothing in there moves, I used better wing bands, I balanced the prop with a balancing device like David Windestal uses, and I balanced the CG until it was perfect. The next morning I launched it. It went really fast about 200 feet in a few seconds right into the woods and smashed apart against the dead trees. This is my best flight so far, and I tried at the very end before impact to control the craft away from the obstacles, but it behaved too wildly to avoid the disaster.
4. I had to rebuild the powerpod, so I did that, and the next morning at 5am, with zero wind, it went nose down immediately and smashed all the skewers and deformed the fuselage, despite the care I took balancing the craft.
5-12. At this point I just took off the motor and threw it around from a hill using the the control surfaces and trying to steer it. it doesn't seem to work very well. It crashed every time straight down.
13. rebuilt the craft from scratch using much more sturdy foam board. same flight characteristics, but it didn't break as badly.
14-17. same thing, crash every time nose down.

Should I add mass to the tail section???

 

[Userofmuchtape&glue]

How much does your TT weigh?

 

[DamoRC]

Hiawatha - welcome to the forum. Sorry you are having so much trouble with the Tiny Trainer.

A couple of questions
(1) What battery are you using (this is related to the question from Useroftoomuchtape and glue)
(2) How much flying experience do you have - is this both your first plane to build and to fly?

It sounds like your initial flights could have been nose heavy. But you say you balanced the plane perfectly on it's CG and it managed the 200 foot dash into the trees. So at least that's some progress! I don't think you should add any excess weight to the plane to balance it. You should be able to move the battery forward so that the plane balances on its CG, as you did before.

Keep filling us in on the details and I'm sure we will be able to help.

DamoRC

 

[Fidget]

For what it's worth, that is exactly how my first 2 flights with my Tiny Trainer went. It was my first build and my first plane after the Champ.
I had my motor spinning backward. Sounds like that's not your problem.
I did eventually add tail weight, as did my wife to hers. Simplest way is to put a glob of glue on top of the fuselage as far back as you can. I could never get the battery far enough back to get it to balance well. DamoRC is right that adding weight is generally bad, but that's what we had to do.

 

[jtrops]

It is better if you can balance it without adding ballast.

Before I built my first TT I read about how it tends to be nose heavy. I saw a vid where the builder placed the servo arms to the outside of the fuselage, and it allowed him to move the servos further back. So I did that and found myself with the opposite problem of needing to move my battery much further forward. I'm about to rebuild the fuse again, and I will try moving the servos just a bit forward of the current spot. In its current configuration it has flown well for a couple of years now, so no complaining.

 

[Hai-Lee]

If you are new to flying and the current radio systems It can be daunting to setup the plane to get a nice and stable flier especially if you have no previous experience.
You did not state if you have the 3 channel or the 4 channel wing on your plane but I suppose the following points are almost equally relevant.
1. If you built from a kit ensure that all of your control deflections are on the lower or lesser side of the recommended range or even slightly less.
2. Add or program in plenty of Expo, (in the transmitter), on all of your control surface channels.
3. Make the plane balance with NO added weight as each extra gram means a faster flying/stall speed.
4. For your first couple of launches only use about half throttle so that the plane will fly lazily away, (level hopefully), and allow you the time to think about your maneuvers before you make them.
5. If possible launch from a slightly elevated position into an area of long grass
6. Buy and fit a prop saver.

Remember the TT can also be used as a hand launched glider, (Free flight), and so should fly quite well without any pilot interference. So persevere and you will soon be the new Ace Pilot in your area!

Have fun!

 

[Tench745]

Ruling out some simpler solutions:
Is your prop on with numbers facing forward?
Is your motor spinning the correct direction?
When you pull back on the right stick, does the elevator move up?
Do your other controls move the correct direction?
If the plane is correctly balanced, can you fly it like a glider with the motor off? (Controlled glide tests)
And lastly, as already mentioned, make sure your control throws are at the suggested low rate setting.

 

[basslord1124]

It does kinda seem like a balance issue to me. I would only just do hand toss glides in some tall grass for now to see how it does. Do it with your battery installed. Adjust battery position as necessary OR add weights as necessary. Honestly, I had to add about 10 cents (in pennies) to my FT Storch to get it to balance right. Are you using the 3 or 4 channel wing?

 

[sprzout]

My first thoughts, as I've had issues where the plane left my hand, only to nose into the ground less than 15 feet away:

1) check your elevator. I threw my first Versa Wing, pulled back on the stick, and watched it immediately nose into the ground because I had the servos reversed, and so pulling back made it go down, pushing up made it go up. I wanted the exact opposite.

2) Check balance. On most planes, this is just a touch back from the leading edge of the wing, but it can be as much as 2" back from the leading edge on some planes.

3) If it's squirrelly, as you're describing, DEFINITELY check your expo and program some in. 30% on your rudder, ailerons, and elevators is a good place to start and you can increase that expo if you find you need it to be softer in the center. What I mean by "softer" is that the stick isn't too responsive when you first start moving it from the center, but the further out you get to the limits, the more responsive it is.

4) Check your trim. Make sure that, when you first start off, all of your surfaces are level. If your plane is immediately nosing down, do you have down elevator being put in? Is the surface locked in a down position so that, no matter what, there's no lift? My dad had that problem with his F22 mini; he didn't center the servos off the start, and didn't do a check to make sure he was going the right way when he tried to maiden the plane. As a result, when he launched the plane for the first time, it nosed down because the elevons on the tail were pointing down, instead of having a slightly upward angle, to give the nose lift. If your plane is balanced at its CG point, you will DEFINITELY want to check the elevator when you power up the plane; that control surface pointing the wrong way or angled way down would be just like a giant sail in the wind and will catch it and plow it into the ground.

 

[cranialrectosis]

Servo's reversed in the tail is where I went too, Sprzout.

I know of no faster way to faceplant than to have the elevators reversed so when you are pulling back on the stick you are driving the plane into the dirt.

If you have the means, film the next outing so we can all see what is going on. Use well lit, well focused video and show us the stick and the control in the same frame. Let us see it when you toss the plane and try to fly. Publish to Youtube and link it here.

If she flies we can all party with you. If she crashes, it makes it easier for us to diagnose and you can learn from the mistakes.

Here is the hard part. Don't get frustrated. These things have a lifespan. Broken props and busted wings are normal. It just means you get to build more as you retire (crash to bits) your planes.

Anyway, welcome to FliteTest. As you can see, you have no shortage of experts and buttheads here. Good luck figuring out which is which and with the plane.

 

[randyrls]

Welcome Hiawatha; Not sure where you are. I would suggest locating the nearest AMA club and taking the plane there to have someone look it over, and maybe help you with a "buddy-box". http://www.modelaircraft.org/membership/clubs.aspx

There is not better way to learn to fly than to have an experienced pilot look over your plane and set the trims correctly.

There are several videos on the Flite Test YouTube about how to pre-flight a plane.