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No idea what is wrong with this ft scout.

#1
So I’ve been working on a few different planes for months now none of which have flown for various reasons but I finally got my scout built and it actually flew. Just one problem, after two minor crashes it is now doing the same thing over and over again. Every time I launch it, it abruptly spirals to the right out of control. I thought it might be a thrust angle issue from the crashes so I built a new power pod and it did the exact same thing. My other thought was it could be torque roll but it used to fly without any sign of a torque roll so that couldn’t be it. I eventually decided to replace the entire airframe and built a whole new plane. But to my great surprise it had the exact same issue. I think it must have to do with my electronics but they all seem like their functioning properly. Does anyone know what this is or how I can fix it? I am a beginner pilot and have just FINALLY gotten one of my planes to fly I would really hate to have to start over with a new plane and electronics. If anyone could help me out I would appreciate it so much. If anyone needs specifications on anything I have those too. Thanks in advance.
 
#2
Is one of your control surfaces reversed? that will cause issues when you go to fly. next did you make sure the cg is not way to far back? a tail heavy plane will go way out of control really easily.
 
#3
Is one of your control surfaces reversed? that will cause issues when you go to fly. next did you make sure the cg is not way to far back? a tail heavy plane will go way out of control really easily.
Yea, I think he might be right, the control surfaces might be reversed, just re-proggram them and you should be good. Though considering it worked fine before the crash I don't really know anything better to do.
 

Boberticus

Active member
#4
so a man walks into a doctors office, and says, "doc, somethings wrong with me, everything hurts.

he pokes his arm, and exclaims "owe!,"
he reaches down with he same finger and pokes his his thigh "ouch, see!!!!"
finally reaching up to his nose, he gently touches his nose, and nearly collaspes, howling in pain...

doctor reaches out, grabs his hand and says, "I think your fingers broke!"

I vote for reversed channel as well, I think your poking a different plane with the same finger...

or maybe trim or wrong model profile. i have this problem that my simulator all my channels are reversed and i have to have a dedicated profile to switch to, if i dont change back my first flight things will go awry.
 

quorneng

Well-known member
#6
jakedews4
If it flew and you have not subsequently disconnected or reprogrammed anything then the problem must be the result of the 'two minor crashes'. Something has got knocked out of shape.
It only takes a minor twist in the wing of a 3 channel plane to make it virtually un flyable and even with ailerons fitted you only have limited authority over a wing twist.
Has the fuselage acquired a bend?
Is the fin still exactly inline down the middle of the fuselage?
Is the rudder inline with the fin when the rudder stick is neutral? and the same for the ailerons if they are fitted?

It can take quite a bit of inspection after even a minor crash to spot if something has got deranged.
 
#7
I have tested all my channels so I know they are not reversed. My CG is the same as when it flew without trouble. As for looking for deformities in the airframe I have just checked again and don’t see anything but I did build a second non crashed airframe that turned just like the first. I don’t mean to shoot down all the ideas but I know it’s not my channels that are reversed and my CG is where my plans say it should be. When I built my second airframe I used it as a chuck glider for a while and it flew perfectly then. I don’t see myself bending or ruining anything from just installing some electronics. I know that when I crashed dirt and dust got inside the plane but I even took apart the motor to make sure no dirt got inside. Would some dirt inside the ESC cause something like this?
 

Ketchup

4s mini mustang
#8
I have tested all my channels so I know they are not reversed. My CG is the same as when it flew without trouble. As for looking for deformities in the airframe I have just checked again and don’t see anything but I did build a second non crashed airframe that turned just like the first. I don’t mean to shoot down all the ideas but I know it’s not my channels that are reversed and my CG is where my plans say it should be. When I built my second airframe I used it as a chuck glider for a while and it flew perfectly then. I don’t see myself bending or ruining anything from just installing some electronics. I know that when I crashed dirt and dust got inside the plane but I even took apart the motor to make sure no dirt got inside. Would some dirt inside the ESC cause something like this?
Do you know if you have any mixes? It is not probable but maybe you have a throttle and aileron mix. Also, is your motor spinning counter clockwise? Maybe you have a reverse prop and a reversed motor. This could add to any thrust angle to mess up flight. One last thing. Do a glide test. This will help to make sure that it is not some sort of motor or throttle issue.
 

CustomRCMods

Well-known member
#10
@Ketchup has a point. If you are running a CW prop instead of CCW, the thrust angle needs to be reversed as well over to the other side. If not, the plane will spiral out of control, or just have trouble turning.

Also, maybe try some chuck tests, see if you can glide it out and all surfaces work properly. If so, then it is an issue with your motor. if not, it is an issue with your airframe or controls.

@RC Fly Time also has a point. you should be using an 8-10 inch prop, anything more, there will likely be torque roll issues when throttle is applied. Also, make sure to power the plane up before it leaves your hand, and be sure not to "spike" the throttle when climbing out, as that will cause torque roll as well. Launch into the wind at 1/2 to 3/4 throttle.
 

Tench745

Well-known member
#11
It may be worth a check. Hold your rudder lightly and move the stick, looking for pushrod deflection, servo chatter, or loose control horns.
Do the same for the elevator.

It's unlikely the new airframe is bad in the same way as the crashed frame, so it would make sense that whatever your problem is migrated with anything that came from the old plane. I would surmise that there is something mechanically wrong with your rudder servo like a stripped gear which only shows up when it's under load.

There is also a chance something goofy happened like your prop was put on backwards, or was accidentally swapped for a reverse rotation prop.
 
#12
Ok, I just found part of the issue. I am running the plane CW since the propellers I got had to spin that way. I think this could be part of the issue but I ran my motor CCW with my old propellers and it still drops its wing to the right. Is there a video on how to reverse the thrust angle? Also, I am using a 6 inch prop on a 2202 2200kv motor. I knew this was probably too small but then again the plane flew so I don’t think a 6 inch could be that bad or it wouldn’t have flown. I always throttle up to 50-75 percent before launching so I don’t think it’s a torque roll. I am using a pretty aggressive pitch on my prop but the only effect I see from it is an increase in the amount of air flow it pushes.
 

CustomRCMods

Well-known member
#13
If none of the above recommendations work, you might want to post a video of you cycling the controls on the scout, as well as detailed pictures of the build and component setups
 

CustomRCMods

Well-known member
#14
Ok, I just found part of the issue. I am running the plane CW since the propellers I got had to spin that way. I think this could be part of the issue but I ran my motor CCW with my old propellers and it still drops its wing to the right. Is there a video on how to reverse the thrust angle? Also, I am using a 6 inch prop on a 2202 2200kv motor. I knew this was probably too small but then again the plane flew so I don’t think a 6 inch could be that bad or it wouldn’t have flown. I always throttle up to 50-75 percent before launching so I don’t think it’s a torque roll. I am using a pretty aggressive pitch on my prop but the only effect I see from it is an increase in the amount of air flow it pushes.
you essentially are rebuilding the power pod with an opposite angle to it, (angled to the left not the right). I usually freehand the thrust angle when I scratch build and everything turns out fine. You may consider just switching prop rotation, thats an easy fix. If the CCW props dont fix it then you may be at an incorrect thrust angle as well.
 
#15
I replaced the servos when I built the new airframe so I know it isn’t those, when I do the holding test my pushrods bend slightly but they also bent that way when I had my plane flying. That’s the only thing I notice with my servos. The motor is pretty cheap so I might just try buying a whole new one to see if that works. I have noticed some slight vibration so I might have a very small bend in my motor shaft. Would small vibration cause the plane to turn so violently? Also, does the scout even have a thrust angle? I haven’t noticed an angle in the power pod.
 

CustomRCMods

Well-known member
#16
I replaced the servos when I built the new airframe so I know it isn’t those, when I do the holding test my pushrods bend slightly but they also bent that way when I had my plane flying. That’s the only thing I notice with my servos. The motor is pretty cheap so I might just try buying a whole new one to see if that works. I have noticed some slight vibration so I might have a very small bend in my motor shaft. Would small vibration cause the plane to turn so violently?
the issue most likely isnt your motor. Vibrations will vibrate the airframe, which is bad in the long run but won't roll you into the ground. I would try flying it as is, and you could even try to fix the bent motor shaft as well.
 
#19
Sorry that’s not what I meant. I ran the motor CW with a CW prop but I have also tried running the motor CCW with a CCW prop. Sadly the same result with both tries. How can I know if my thrust angle is off? Is there a test I could do?