Help! Recommendations for the first flight

Belial2801

Member
Hi sorry if my english is bad. Yesterday I flew my plane for the first time (ft simple cub) and I had some problems, the first is that when taking off from the ground you can see that it is going directly to the left (I took off from further back but I lost that recording), in the following video i pulled it from my hand, it stopped and went again, i think i didn't fly because i put too much force on the elevator and it caused it to stall, i would like to know your opinions.

Setup:

a2212 1000kv motor
1045R prop (cw at the time, currently i have ccw)
3S 1500 mAh.

I have certain doubts about the CG, I looked at the plans and it is in 45mm but when I calculate it myself it gives a measurement of 60mm

Here is the video of both crashes:
 

FlyerInStyle

Elite member
Hi sorry if my english is bad. Yesterday I flew my plane for the first time (ft simple cub) and I had some problems, the first is that when taking off from the ground you can see that it is going directly to the left (I took off from further back but I lost that recording), in the following video i pulled it from my hand, it stopped and went again, i think i didn't fly because i put too much force on the elevator and it caused it to stall, i would like to know your opinions.

Setup:

a2212 1000kv motor
1045R prop (cw at the time, currently i have ccw)
3S 1500 mAh.

I have certain doubts about the CG, I looked at the plans and it is in 45mm but when I calculate it myself it gives a measurement of 60mm

Here is the video of both crashes:
use the cg given on the plans, not the one they give online. Also try to see if your rates are too high, and as a side note that flying space is a little too small, try to find an open field in daylight, to preveent more crashing. As for your nose down, give it throuttle AND UP elevator (you may have your elevator reversed, when you move the stick down, your elevator should move up, and htat is up elevator. then you should be in the air. The turning may have been caused by more friction on one wheel than the other you cant really do anything about that, so jsut compensate with rudder.
 

Merv

Site Moderator
Staff member
... it is going directly to the left...
Make sure both wheals turn freely.
You want a bit of toe in. The wheels should point to a spot 5-10 feet in front of the plane.
... the CG, I looked at the plans and it is in 45mm but when I calculate it myself it gives a measurement of 60mm.
On a rectangular wing, like the cub, the CG should be 25% of the wing cord alone, not the cord plus the aileron.
 

Belial2801

Member
Make sure both wheals turn freely.
You want a bit of toe in. The wheels should point to a spot 5-10 feet in front of the plane.

On a rectangular wing, like the cub, the CG should be 25% of the wing cord alone, not the cord plus the aileron.
Thanks, i didnt know that, after that attempt if I notice that there is a wheel that does not work well, I will fix it and see what happens.
 

Belial2801

Member
use the cg given on the plans, not the one they give online. Also try to see if your rates are too high, and as a side note that flying space is a little too small, try to find an open field in daylight, to preveent more crashing. As for your nose down, give it throuttle AND UP elevator (you may have your elevator reversed, when you move the stick down, your elevator should move up, and htat is up elevator. then you should be in the air. The turning may have been caused by more friction on one wheel than the other you cant really do anything about that, so jsut compensate with rudder.
The surfaces are fine, except that the elevator doesn't move the same, I fixed it yesterday but it moves up almost 20 degrees and down just 10 degrees. Couldn't that affect it?
 

FlyerInStyle

Elite member
The surfaces are fine, except that the elevator doesn't move the same, I fixed it yesterday but it moves up almost 20 degrees and down just 10 degrees. Couldn't that affect it?
yeah, 20 degrees is too much keep it below 15, better even lower it to 10 for both
 

FlyerInStyle

Elite member
Hi, i already fixed the elevator but i have a question, when I launched the plane from my hand it went to the left, couldn't that be caused by the propeller?
I dought it, the prop would cause more of a rolling motion, check if your qings are eqal size, have the same angle up, and if your rudder and elevator are even
 

Merv

Site Moderator
Staff member
..., when I launched the plane from my hand it went to the left,...
It’s unlikely the roll is caused by the prop. Prop roll is most prominent while the motor accelerating, that is gaining RPM’s. Moving the throttle very quickly to full throttle. Torque roll is normally not much of an issue. I slam my throttle to full all the time, without any issue, but it can happen.

There are several more likely possibilities. You could be causing the roll by your throw, like throwing a football spiral. You could have unintentionally built a twist into the wing. But the most likely, your plane just needs to by trimmed to fly straight.
 

Foamforce

Well-known member
You might also just be going too slow and stalling. In the second video above, you were going very slowly. The first video doesn’t mean anything because that could have just been the landing gear.

A lot of my first flights ended very similarly to yours. I would get enough speed to pull up the nose and then the plane would roll to the left and crash. A friend pointed out that I was probably stalling, so next time I gave it more throttle and got more speed before pulling up and that solved the problem for me.

That may not be your problem though. YMMV
 

JDSnavely

Member
You might also just be going too slow and stalling. In the second video above, you were going very slowly. The first video doesn’t mean anything because that could have just been the landing gear.

A lot of my first flights ended very similarly to yours. I would get enough speed to pull up the nose and then the plane would roll to the left and crash. A friend pointed out that I was probably stalling, so next time I gave it more throttle and got more speed before pulling up and that solved the problem for me.

That may not be your problem though. YMMV
I agree 100%. My son and I were flying a Mini Mustang with a simple receiver (no as3x or SAFE). We continued to crash and I continued to fix. Finally, after 5 crashes and fixes (me and him) I said just go for it--full throttle. It flew perfect. We were both flying too cautious and were stalling it when we thought it wasn't set up correctly. It's actually kid of surprising because my son prefers to fly fast.
 

quorneng

Master member
Have you tried simply gliding your Cub from a hand launch?
If you can achieve, it may take several attempts, a reasonably straight & smooth glide with no RC control by adjusting the control surfaces you know the plane will at least fly.
It can useful to use only a little power to start with on a hand launch even if it only extends the glide. At low power it should still fly with little or no control input. Once you have increased the power enough so it actually maintains height then simply close the throttle and let it land before it goes too far.
With a bit more power applied it will climb then its up to you to control where it goes. Don't be afraid of gaining altitude. It gives you more time if things go wrong to get things sorted before it hits the ground!
Keeping low may look safer but until you have quite a bit of flying skill it just means it will hit the ground before you have time to work out what to do.
 

TheOldMonk

Member
Have you tried simply gliding your Cub from a hand launch?
If you can achieve, it may take several attempts, a reasonably straight & smooth glide with no RC control by adjusting the control surfaces you know the plane will at least fly.
It can useful to use only a little power to start with on a hand launch even if it only extends the glide. At low power it should still fly with little or no control input. Once you have increased the power enough so it actually maintains height then simply close the throttle and let it land before it goes too far.
With a bit more power applied it will climb then its up to you to control where it goes. Don't be afraid of gaining altitude. It gives you more time if things go wrong to get things sorted before it hits the ground!
Keeping low may look safer but until you have quite a bit of flying skill it just means it will hit the ground before you have time to work out what to do.
I always prefer to test the airframe first by putting dead weight equal to motor and battery - and do many glide test to fix the airframe profile. I find it a good practice more essentially since I scratch build most of my models.
 

Belial2801

Member
Have you tried simply gliding your Cub from a hand launch?
If you can achieve, it may take several attempts, a reasonably straight & smooth glide with no RC control by adjusting the control surfaces you know the plane will at least fly.
It can useful to use only a little power to start with on a hand launch even if it only extends the glide. At low power it should still fly with little or no control input. Once you have increased the power enough so it actually maintains height then simply close the throttle and let it land before it goes too far.
With a bit more power applied it will climb then its up to you to control where it goes. Don't be afraid of gaining altitude. It gives you more time if things go wrong to get things sorted before it hits the ground!
Keeping low may look safer but until you have quite a bit of flying skill it just means it will hit the ground before you have time to work out what to do.
I tried the glide test launching it the same way but without the electronics, I'll try it with the electronics to see how it flies, in that video I went directly to the flight without the glide test
 

mbyvz

New member
Hello, I am new to this hobby too. My simple cub weighs 600g. 3s battery, a2212 1000kv motor with 80x40 propeller do you think it would be suitable? i gave the model an engine angle of 3 degrees clockwise. is this a wrong transaction ?
 

FlyerInStyle

Elite member
Hello, I am new to this hobby too. My simple cub weighs 600g. 3s battery, a2212 1000kv motor with 80x40 propeller do you think it would be suitable? i gave the model an engine angle of 3 degrees clockwise. is this a wrong transaction ?
It does not need the 3 degrees. which direction your motor is spinning in. It should still fly fine but I recommend removing the 3 degrees though.
 

mbyvz

New member
It does not need the 3 degrees. which direction your motor is spinning in. It should still fly fine but I recommend removing the 3 degrees though.
Ok.
I will remove thrust angle. How about, a2212 1000kv motor with 80x40, weighs 600g is it suitable ?
Thank you for answer.
 

Belial2801

Member
Hello, I am new to this hobby too. My simple cub weighs 600g. 3s battery, a2212 1000kv motor with 80x40 propeller do you think it would be suitable? i gave the model an engine angle of 3 degrees clockwise. is this a wrong transaction ?
Hey, I don't think it's a good idea to give the engine some angles, did you make it from the same material as the video? The final weight of mine is around 28oz, I used the same electronics and material, that's something that still worries me because I haven't been able to fly it yet. I recommend at least a 9x5 propeller for that engine, look for the datasheet and it will help you choose a propeller.