DIY FT Simple Cub

[FrenchBaguette]

Hi,

I have finished a scratch built FT Simple Cub, and I wanted to check if anything seems to go wrong when just trying to taxi on a clean surface.
And when I increase throttle, the plane starts moving, but always turning to the left. If I increase throttle it is worst.
I checked that wheels are aligned.

But I guess this is due to the engine torque, no ? But in this model, unlike in the mini series, there is no right angle on the firewall (I checked the plans).

did I miss something ?
I guess that will do the same if I try to fly that way (turning left) and I will crash my first plane !

Any advice ?

Regards

 

[Matthewdupreez]

Hi,

I have finished a scratch built FT Simple Cub, and I wanted to check if anything seems to go wrong when just trying to taxi on a clean surface.
And when I increase throttle, the plane starts moving, but always turning to the left. If I increase throttle it is worst.
I checked that wheels are aligned.

But I guess this is due to the engine torque, no ? But in this model, unlike in the mini series, there is no right angle on the firewall (I checked the plans).

did I miss something ?
I guess that will do the same if I try to fly that way (turning left) and I will crash my first plane !

Any advice ?

Regards

there is no thrust angle on the ft simple cub power pod, all you have to do is apply some right rudder on taxing, the drift to the left should be unnoticeable while flying, if it is just apply some right trim

 

[FrenchBaguette]

Thanks, I'm more confident for my first fly (just waiting for the appropriate weather)

 

[Hvon11]

I fly off grass so I hand launch. My cub did not need any rudder trim in the air but needed all the trim I could give for up elevator. After landing I adjusted elevator Sub Trim and returned the slider trim to zero. It now holds a level attitude at 3/4 throttle. A very fun plane to fly, nice and slow.

 

[Matthewdupreez]

Thanks, I'm more confident for my first fly (just waiting for the appropriate weather)

hehehe, i know that feeling.
although we are going to my grans place in 2 weeks time and they have lovely big open fields.
my main issue holding me back is lack of time

 

[Matthewdupreez]

Thanks, I'm more confident for my first fly (just waiting for the appropriate weather)

one quick thing check that you didn't accidentally cut the front of the power pod skew, make sure that it is at right angles with the firewall

 

[FrenchBaguette]

Hum, I checked once again and there is no thrust angle on the plan, and the front of the power pod is squared, so I don't see which skew you're talking about (and that scares me ...)

 

[Matthewdupreez]

Hum, I checked once again and there is no thrust angle on the plan, and the front of the power pod is squared, so I don't see which skew you're talking about (and that scares me ...)

i meant not symmetrical, skew is slang for it here in south africa.
okay if it is at a right angle to the power pod you are fine, it has to be motor torque or you have some left rudder.
but if neither of these just apply some right rudder on take off

 

[FrenchBaguette]

based on your comments, I just made a small experiment, and i (gently) pushed the plane on the ground without the motor running, and it turned left ! So I think you're right it is not the torque. I twisted the landing gear to the right and now it goes straight.
I think I may be too stressed for my first flight.

 

[Matthewdupreez]

based on your comments, I just made a small experiment, and i (gently) pushed the plane on the ground without the motor running, and it turned left ! So I think you're right it is not the torque. I twisted the landing gear to the right and now it goes straight.
I think I may be too stressed for my first flight.

just relax and have fun.
if you do crash remember it is only foam, so if you need to rebuild it will only be one afternoon. no big deal.

 

[Hvon11]

The Cub is a gentle flyer. You will be fine. Easy to fix too. Climb, bank left, level off, deep breath, have fun...

 

[FrenchBaguette]

Thanks all
Moreover I guess hours on simulator will help.
But currently it is raining or windy !!!!

 

[Matthewdupreez]

Thanks all
Moreover I guess hours on simulator will help.
But currently it is raining or windy !!!!

if you have a sim practice on that when you can't fly outside

 

[FrenchBaguette]

I try to spend at least 1/2 hour a day on sim
Now that I'm a bit more confortable with flying, I practice landing, but I'm still often bouncing when touching the ground.

 

[daxian]

standard practice when landing ...takes a lot of practice to land without the bounce !! still not managed it myself...lol !!
take off the wheels and belly land in grass till you get the hang of flaring into the wind .

 

[Matthewdupreez]

I try to spend at least 1/2 hour a day on sim
Now that I'm a bit more confortable with flying, I practice landing, but I'm still often bouncing when touching the ground.

cut power high and glide in slowly, let the plane stall just above the ground

 

[FrenchBaguette]

I finally flew for the first time this morning.
The weather was not ideal, quite windy, but I could not wait anymore ;-)
This first flight was not nice and clean, and not only due to the wind.

At first throw, the plane flew less than 3s before crashing and break the propeller. I also lost all my rubber bands!
Actually, as I saw, after thrown, it hardly banked left and I did not get a chance to compensate !

I trimmed right, but on the second throw it started to bank left again. But as I was ready I managed to compensate giving rudder on the right (my plane is a 3 channel version, so no ailerons).
Due to the wind it is hard to say how it flies except this strong left banking. Due to that, it badly turns right.

After three tries and 2 propellers, the wind became too strong so I had to give up. But even after two crashes and a hard landing the plane can still fly

Back to the workbench, I checked the dihedral symmetry and I noticed that left wing is lower than right wing of 2 cm.
Is this problem can explain the hard left banking ?

 

[Matthewdupreez]

I finally flew for the first time this morning.
The weather was not ideal, quite windy, but I could not wait anymore ;-)
This first flight was not nice and clean, and not only due to the wind.

At first throw, the plane flew less than 3s before crashing and break the propeller. I also lost all my rubber bands!
Actually, as I saw, after thrown, it hardly banked left and I did not get a chance to compensate !

I trimmed right, but on the second throw it started to bank left again. But as I was ready I managed to compensate giving rudder on the right (my plane is a 3 channel version, so no ailerons).
Due to the wind it is hard to say how it flies except this strong left banking. Due to that, it badly turns right.

After three tries and 2 propellers, the wind became too strong so I had to give up. But even after two crashes and a hard landing the plane can still fly

Back to the workbench, I checked the dihedral symmetry and I noticed that left wing is lower than right wing of 2 cm.
Is this problem can explain the hard left banking ?

hmmm. i don't think that should cause to much of a problem.
i would say place a BBQ skewer under the let side of the wing on the fuselage to straighten out the dihedral.
i think that the left bank would be the wind maybe you were not flying perfectly into the wind?

 

[FrenchBaguette]

Thanks for the advice, this is what I have done to level up the left wing.
You're right for the first throw I was not perfectly in the wind.
But while flying I still felt this left banking but hard to say if I was perfectly into the wind.

I will try next time with better weather conditions.

 

[RossFPV]

Hey my cub turn left hard and mine was in ZERO wind. Did you manage to fix it? What did you do to fix it?