Help! Help with my first rc plane build

[ccc]

I just built the simple cub and followed josh's build video and am using the flite test power pack C. It looked great but when tried to fly it, it went up and then nose dives left. Like I said I am not a experienced pilot. Can someone please help me because I have crashed it twice and broke 2 props already without getting it flying.
thanks

 

[Mr NCT]

Nose diving to the left at launch is prop torque. I'm assuming your CG is correct, maybe a little nose heavy. Are you hand launching or taking off from the ground? If you're taking off from the ground you probably see it pulling left as it accelerates and the right wing lifting. You can counter that with right rudder. Hand launching is the same thing but you don't have as much time to do it. The higher the throttle the worse it will be. It's a balancing act (even in a real plane) to accelerate and counter the prop torque.

 

[quorneng]

It looked great but when tried to fly it, it went up and then nose dives left.

It sounds like your plane is not set up correctly. Are you hand launching it or taking off from a smooth surface?
Is the balance point (CofG) in the correct place according to the plan?
Are the control surfaces in the neutral position?
Has the motor the correct down & right thrust?
Unless these sorts of things are correct it is unlikely you will be able to fly it.
Is there any chance you could get an experienced flyer to look over the plane as he would likely to spot any obvious errors.

 

[MrClean]

Like I said I am not a experienced pilot.

Clarify for us. How much flight time do you have? Have you flown other airplanes or is this your first? Your problems could easily be caused by bad hand launch technique or by an incorrect CG, Control surface throw, reversed controls, Oh so much. Built per plans with the CG correct and controls with recommended power pack, it is a good flying plane (from all I've seen online). We need to start narrowing down your symptoms.

 

[ccc]

Well thank you for replying, and I will clarify a to my best I do not have anyone to help me to start. I do not have any expierince except with the sport cub s and I am trying to do a hand and ground lanuch. both crashed

 

[ccc]

i dont know how to properly set up the trust angle and also i tried to do very light controls but they crashed . I used power pack c with 1800 mAh 3s and 10 4.5 prop but they both broke .

 

[ccc]

i dont know how to properly set up the trust angle and also i tried to do very light controls but they crashed . I used power pack c with 1800 mAh 3s and 10 4.5 prop but they both broke .

Also what prop would someone recomend

 

[MrClean]

the props came with the powerpak which is recommended for the cub so I'll assume they're the right prop. The pack is also recomended but also the heaviest of the three recommended. That's going to make it heavier and you'll need to have the cg right. Should be do-able or they shouldn't recommend it as an option. Wish it listed the weight of the packs in the description OR that the powerpaks would have breakouts in the descriptions. The heavier the aircraft weight the faster it will need to fly, the difference in this particular plane I can't say.
How did the CG come out with the battery installed? At or just a tad forward of the recommended location? This is also critical.
As a secondary aircraft the Cub would be a fine airplane. As a primary, i'd be more comfortable recommending the Explorer. It's high mounted pusher prop design helps keep you from eating a prop. You WILL need to by more props. I knew people that would collect the props they busted on a cord. Don't know how long they were planning on doing that. I have enough stuff thats usable. Also, the explorer can be flown without power, just toss and glide.

Lets go with the plane you have. You'll need some more props. The battery pack is an ounce heavier. Not that great of a difference though lighter is better. climbing and diving into the ground is a pretty standard tailheavy symptom. Just makes it exceptionally touchy to control.
HOW are you measuring your CG. It looks on the plans to be just forward of the front fold on the wing. You can use your fingertips, there are other ways but this will get it close. CG with battery installed and prop on the plane, motor unhooked so you can't have it spin up on you.

 

[MrClean]

Also, and you may not love this idea, the Mighty Mini trainer plans are online, It DOES use a smaller powerpack and battery but I'mma go way out here and say, build one as a glider, no power, and use a receiver battery for your radio. Just put the battery and rx up front without motor and build it out of Dollar Tree foamboard. Thats just so you don't have to put out any real money. If you have a hill around you should be able to build balance and glide this for some distance to get your basic flight controls down. I started with a 1meter Carl Goldberg glider once upon a time. Taught myself to fly those. When I went powered there wasn't an easy step up, kinda a big one. There I had a club to teach me. But we can go this way. The Tiny Trainer is listed as an easier to fly plane then the cub. If you don't have a prop on the front you don't have to worry about breaking those either. Just options mind you. https://www.flitetest.com/articles/flite-test-tiny-trainer

 

[mastermalpass]

i dont know how to properly set up the trust angle and also i tried to do very light controls but they crashed . I used power pack c with 1800 mAh 3s and 10 4.5 prop but they both broke .

How is your motor mounted to the firewall? If you have screws going through its metal 'X' mount into the wood (or through the wood into nuts on the other side), you can slip washers between the mount and the wood to angle it off.

To figure out which direction to angle the motor off, view your plane from behind and check which way the prop spins. If it spins clockwise, then your plane will want to roll counter-clockwise, point the motor off to the right, to balance it out. If the motor spins counter-clockwise, the plane will want to roll clockwise, point the motor off to the left to balance it out.

This takes a lot of the rudder management work out, as increasing the throttle now not only increases the torque roll but also increases the yaw-thrust that balances it out. It won't be perfect, but it will make it much easier.

A bit of down thrust can be helpful too. This is simply the case of angling your motor down a bit. Use the same washer technique that you used to angle it off left or right.

 

[Shurik-1960]

This should become your habit: we always throw a new plane and trim it. As a result, the model should fly straight and smoothly. We start with a smooth gas supply: if the model pulls to the left, we plant and add 1-2 washers under the engine leg (add a slope to the right), if the plane goes to the right, we plant and reduce the washers, reducing the slope to the right. If the model pulls up strongly, we increase the tilt of the engine down... This is how the new model is arranged, which then flies like on rails.

 

[ccc]

OK just got new props what should i do now

 

[Burnhard]

OK just got new props what should i do now

Have you checked your CG? You write that the aircraft went up. Sounds like its tail heavy. Just to note, even if you perfectly followed the plans, sometimes the FT aircraft still need a fair bit of weight in the nose. You should check that the CG is right.

Thereafter you should check your throws on the control surfaces. Too much throw makes the aircraft rather touchy. More is not always better.

 

[ccc]

OK done now what should I put down and right thrust? And if so how should i do it and with what materials? Do they come with the prop or what?

 

[Burnhard]

OK done now what should I put down and right thrust? And if so how should i do it and with what materials? Do they come with the prop or what?

For the down right thrust you need to tilt the motor. Normally the power pods are designed that they have the correct thrust angle. If you want to do that manually you need to put a washer under the screw with wich the motor is fixed to the fire wall on the opposite side of the thrust angle you want to achieve (if you want to add right thrust angle add the washer one the left side).

 

[Shurik-1960]

The photo shows the washer under the right paw of the engine

 

[ccc]

Alright so how do you fly a rc plane now?=

 

[ccc]

like what throttle should i be at and what are the controls for the FT simple cub wiht power pack C

 

[Burnhard]

like what throttle should i be at and what are the controls for the FT simple cub wiht power pack C

Before you start, add some expo to your controls (30-40%). Check that all control surfaces move in the right direction. If you have ailerons installed, if you pull the stick to the left, the left aileron (from the perspective of the pilot in the aircraft) must go up.

If you have a landing gear installed, first do some taxi tests that your aircraft is pulling straight (start slow and slightly increase speed on the next try). If its turning to one side trim via rudder until its pulling straight.

When you go for lift off, quickly accelerate to 75 per cent throttle (or higher) and slightly pull the elevator. That should be enough for a smooth lift off. If it noses over on the ground, pull the elevator a bit harder next time (depends a bit on the ground. On grass the aircraft needs to slowly roll before moving up throttle). Try not to climb to steep as otherwise you risk a stall (40 degrees max). Once in the air gain a bit of altitude (maybe 20-40m) and start trimming via your radio. If it pulls up when the stick is centered trim the elevator. If you have ailerons installed and it yanks to one side when the stick is centered trim the ailerons.

If you have ailerons installed, try not to yank it over 45 degrees. Once you yank the plane to 45 degrees move the stick bak to center. You can make the turn smaller by slightly pulling on the elevator (yank and bank). The centering of the elevator stick is important as if you continue to hold it to one side, the aircraft will do half a roll and once upside down will likely crash (I have seen this with my son who at first did not understand the difference between aileron and rudder).

Ask a friend to do a video. That way you can later check in case anything did not go according to plan.

Don‘t worry if you crash. That‘s part of the learning experience and you can always cut a new piece of foamboard. Hope all will go well.

 

[ccc]

Thank you, although what is expo, and how does it affect the plane? And I don't have landing gear and finally how should i start the takeoff?