Help! problem with my first rc plane

[Riki10]

Hi guys, this is my first post so i hope i'am doing everything right.
One year ago i started building my first rc plane based on a design that i found on this site (link:https://www.flitetest.com/articles/ft-style-mighty-mini-p40-warhawk). I know it isn't a design for a beginner but i tought that the difficult part was building it. I think it's important to note that i wasn't looking for an rc plane design, I saw it randomly on my Youtube homepage and I thought "I must build this." Here I am, one year later and after having rebuilt it twice (i snapped the wings so many time i just couldn't fix the first version again) asking for advice. I just can't get it to glide. The problem with the first design was that is was too heavy on the tail, now i fixed it and the new center of gravity is about over the first crease of the wing but it still fly more like a rock than a plane. I am usign a 1000 kv motor with a 3s battery. I've made my own flight controller with an esp32, but i don't think it's the problem given that i am still not gliding. I've tried to give you the big picture but is probable that i'am missing something, as i said i am not an expert so it passible that i am forgetting to say something important. I am just getting frustrated because I can't see any improvment. If you could help me understand on what i should focus it would be amazing, ther's clearly something i am not understanding.

thanks for reading so far, Riccardo
(Ps. english is not my first language so i hope i haven't written anything too strange)
(I've attched a picture of my latest flight, as you can see i might need a new wing)

 

[Houndpup Rc]

Hi guys, this is my first post so i hope i'am doing everything right.
One year ago i started building my first rc plane based on a design that i found on this site (link:https://www.flitetest.com/articles/ft-style-mighty-mini-p40-warhawk). I know it isn't a design for a beginner but i tought that the difficult part was building it. I think it's important to note that i wasn't looking for an rc plane design, I saw it randomly on my Youtube homepage and I thought "I must build this." Here I am, one year later and after having rebuilt it twice (i snapped the wings so many time i just couldn't fix the first version again) asking for advice. I just can't get it to glide. The problem with the first design was that is was too heavy on the tail, now i fixed it and the new center of gravity is about over the first crease of the wing but it still fly more like a rock than a plane. I am usign a 1000 kv motor with a 3s battery. I've made my own flight controller with an esp32, but i don't think it's the problem given that i am still not gliding. I've tried to give you the big picture but is probable that i'am missing something, as i said i am not an expert so it passible that i am forgetting to say something important. I am just getting frustrated because I can't see any improvment. If you could help me understand on what i should focus it would be amazing, ther's clearly something i am not understanding.

thanks for reading so far, Riccardo
(Ps. english is not my first language so i hope i haven't written anything too strange)
(I've attched a picture of my latest flight, as you can see i might need a new wing)

Hey! Welcome to the forum!
How many mah is you battery?
I am wondering if maybe your setup is too heavy.....You mentioned that you have a 1000kv motor, usually that size is for bigger planes like 35" wing span and up, where as smaller ones like this have like a 2200kv+ with a 6" prop.
What is your all up weight?

 

[Mr Man]

Welcome!

So I’m guessing you have a 2212 1000kv motor, what prop are you spinning? And like @Houndpup Rc said, what mah is that 3s? That plane is supposed to use a 2204 2300kv motor spinning a 6x4.5 propeller.

 

[Riki10]

Hey! Welcome to the forum!
How many mah is you battery?
I am wondering if maybe your setup is too heavy.....You mentioned that you have a 1000kv motor, usually that size is for bigger planes like 35" wing span and up, where as smaller ones like this have like a 2200kv+ with a 6" prop.
What is your all up weight?

Thanks for the reply,
the battery is a 3000mah 15c battery. I've just weighted the plane and the grand total is around 450grams (0.99 pound if that's the right unit). I am using a 6inch propeller I had laying around (I think it's a spare for an old toy drone). So you think it needs more power? I mean, now that i am saying it up loud it is really heavy, given that I've ditched some weight from the original model and my electronic is particulary light i tought i could get away with a larger battery i had laying around but it's definitly heavyer that the ones in the article. Do you think that a more powerfull motor is gonna cut it? I could remove one of the three cells of the battery to gain some weight but the voltage is gonna drop and the motor will spin slower

 

[Riki10]

Welcome!

So I’m guessing you have a 2212 100mv motor, what prop are you spinning? And like @Houndpup Rc said, what mah is that 3s? That plane is supposed to use a 2204 2300kv motor spinning a 6x4.5 propeller.

thanks for the reply,
Exactly the motor is a 2212 (I am not sure about the 100mv). The battery is a 3000mah 15c battery. I am using a 6inch propeller but i don't know what is his pitch, I had it laying around and i tought i would give it a shot. So based on what you have told me is too heavy for the motor i am using. do you think that a more powerfull motor will be enough or do you think i also need to make it lighter? I could remove one of the three cells of the battery to reduce the weight but then the motor will spin slower(i could use a boost converter to take the voltage from the 7volt of a two cell to the 12 of a three cell but it has its weight, less then a cell but still...)

 

[Houndpup Rc]

Thanks for the reply,
the battery is a 3000mah 15c battery. I've just weighted the plane and the grand total is around 450grams (0.99 pound if that's the right unit). I am using a 6inch propeller I had laying around (I think it's a spare for an old toy drone). So you think it needs more power? I mean, now that i am saying it up loud it is really heavy, given that I've ditched some weight from the original model and my electronic is particulary light i tought i could get away with a larger battery i had laying around but it's definitly heavyer that the ones in the article. Do you think that a more powerfull motor is gonna cut it? I could remove one of the three cells of the battery to gain some weight but the voltage is gonna drop and the motor will spin slower

thanks for the reply,
Exactly the motor is a 2212 (I am not sure about the 100mv). The battery is a 3000mah 15c battery. I am using a 6inch propeller but i don't know what is his pitch, I had it laying around and i tought i would give it a shot. So based on what you have told me is too heavy for the motor i am using. do you think that a more powerfull motor will be enough or do you think i also need to make it lighter? I could remove one of the three cells of the battery to reduce the weight but then the motor will spin slower(i could use a boost converter to take the voltage from the 7volt of a two cell to the 12 of a three cell but it has its weight, less then a cell but still...)

So yeah, that's your problem right there:
1. Your battery should be right around 850mah max
2. if you are using a 6" prop and only 1000kv that is way under powered (a 2200kv will spin more than twice the speed)
3.Your plane should weigh around 250 - 300grams.

Here is some electronics that would work better:
Here is budget:

2205 2300kV 3-4S RS2205 Brushless Counter Clockwise (CCW) Motor | SpeedyFPV

RS2205 Brushless Motor Features: CCW screw thread motor comes with silver locking M5 nut RS2205 Brushless Motor Specifications: Item name: RS2205 2300KV Brushless Motor RPM/V: 2300KV Height: 31.5mm Width: 27.9mm Shaft diameter: M5 Motor mount hole size: M3 Weight: 28 grams Battery: 3-4S lipo...

speedyfpv.com

Turnigy 700mAh 3S LiPo Battery Pack 11.1V 60C 120C XT30 Connector Plug | SpeedyFPV

Turnigy batteries are equipped with heavy duty discharge leads to minimise resistance and sustain high current loads. Turnigy batteries stand up to the punishing extremes of aerobatic flight and RC vehicles. Each pack is equipped with gold plated connectors and JST-XH style balance...

speedyfpv.com

Turnigy Nano-Tech 850mAh 4S 14.8V LiPo Battery 25C (XT60 Connector) | SpeedyFPV

Specifications: Capacity: 850mAh Voltage: 4S1P / 4 Cell / 14.8V Discharge: 25C Constant / 50C Burst Weight: 106g Dimensions: 55x31x34.5mm Balance Plug: JST-XHR Discharge Plug: XT60 Discharge Wire Diameter: 14AWG

speedyfpv.com

Here is more quality stuff:

Turnigy Nano-Tech 850mAh 4S 14.8V LiPo Battery 25C (XT60 Connector) | SpeedyFPV

Specifications: Capacity: 850mAh Voltage: 4S1P / 4 Cell / 14.8V Discharge: 25C Constant / 50C Burst Weight: 106g Dimensions: 55x31x34.5mm Balance Plug: JST-XHR Discharge Plug: XT60 Discharge Wire Diameter: 14AWG

speedyfpv.com

https://speedyfpv.com/collections/b...es-2306-brushless-motor-3-6s-1700-1900-2400kv

And here are some good props:

HQProp 6X4.3 6043 6 Inch Propellers Set (2x CW / 2x CCW) Poly Carbonat | SpeedyFPV

Specifications: Propeller Diameter: 6 Inches Pitch: 4.3 Blades: 2 Material: Poly Carbonate Weight: 4.7g Hub Diameter: 13mm Hub Thickness: 6mm Shaft Diameter: 5mm Package Contents: 2x HQProp 6X4.3 Ethix Propellers (CW) 2x HQProp 6X4.3 Ethix Propellers (CCW)

speedyfpv.com

Here is a video of me using the more quality motor on the FT mini Mustang which is similar size

 

[Riki10]

So yeah, that's your problem right there:
1. Your battery should be right around 850mah max
2. if you are using a 6" prop and only 1000kv that is way under powered (a 2200kv will spin more than twice the speed)
3.Your plane should weigh around 250 - 300grams.

Here is some electronics that would work better:
Here is budget:

2205 2300kV 3-4S RS2205 Brushless Counter Clockwise (CCW) Motor | SpeedyFPV

RS2205 Brushless Motor Features: CCW screw thread motor comes with silver locking M5 nut RS2205 Brushless Motor Specifications: Item name: RS2205 2300KV Brushless Motor RPM/V: 2300KV Height: 31.5mm Width: 27.9mm Shaft diameter: M5 Motor mount hole size: M3 Weight: 28 grams Battery: 3-4S lipo...

speedyfpv.com

Turnigy 700mAh 3S LiPo Battery Pack 11.1V 60C 120C XT30 Connector Plug | SpeedyFPV

Turnigy batteries are equipped with heavy duty discharge leads to minimise resistance and sustain high current loads. Turnigy batteries stand up to the punishing extremes of aerobatic flight and RC vehicles. Each pack is equipped with gold plated connectors and JST-XH style balance...

speedyfpv.com

Turnigy Nano-Tech 850mAh 4S 14.8V LiPo Battery 25C (XT60 Connector) | SpeedyFPV

Specifications: Capacity: 850mAh Voltage: 4S1P / 4 Cell / 14.8V Discharge: 25C Constant / 50C Burst Weight: 106g Dimensions: 55x31x34.5mm Balance Plug: JST-XHR Discharge Plug: XT60 Discharge Wire Diameter: 14AWG

speedyfpv.com

Here is more quality stuff:

Turnigy Nano-Tech 850mAh 4S 14.8V LiPo Battery 25C (XT60 Connector) | SpeedyFPV

Specifications: Capacity: 850mAh Voltage: 4S1P / 4 Cell / 14.8V Discharge: 25C Constant / 50C Burst Weight: 106g Dimensions: 55x31x34.5mm Balance Plug: JST-XHR Discharge Plug: XT60 Discharge Wire Diameter: 14AWG

speedyfpv.com

https://speedyfpv.com/collections/b...es-2306-brushless-motor-3-6s-1700-1900-2400kv

And here are some good props:

HQProp 6X4.3 6043 6 Inch Propellers Set (2x CW / 2x CCW) Poly Carbonat | SpeedyFPV

Specifications: Propeller Diameter: 6 Inches Pitch: 4.3 Blades: 2 Material: Poly Carbonate Weight: 4.7g Hub Diameter: 13mm Hub Thickness: 6mm Shaft Diameter: 5mm Package Contents: 2x HQProp 6X4.3 Ethix Propellers (CW) 2x HQProp 6X4.3 Ethix Propellers (CCW)

speedyfpv.com

Here is a video of me using the more quality motor on the FT mini Mustang which is similar size

Thanks again, seeing your similar model fly was reassuring, spending the winter rebuilding the plane and destroying it at my first attempt was a bummer. I will definitly change the motor. About the battery i was wondering if the only problem about using one with a too large capacity is it's weight. I don't think i could drop 150 grams without touching the battery but if i could do so it would be okey? As I said I am using a diy flight controller, i don't know how energy efficient it is but i fear that a normal sized battery would drain quicker. I don't want to change it for a commercial one because I'd like to fiddle with it when and if the plane will fly... While I am waiting for the components is there anything else i should check on the plane aerodynamically speaking, something easy to mess up that i might haven't noticed?(beside rebuilding the wing)

 

[Houndpup Rc]

Thanks again, seeing your similar model fly was reassuring, spending the winter rebuilding the plane and destroying it at my first attempt was a bummer. I will definitly change the motor. About the battery i was wondering if the only problem about using one with a too large capacity is it's weight. I don't think i could drop 150 grams without touching the battery but if i could do so it would be okey? As I said I am using a diy flight controller, i don't know how energy efficient it is but i fear that a normal sized battery would drain quicker. I don't want to change it for a commercial one because I'd like to fiddle with it when and if the plane will fly... While I am waiting for the components is there anything else i should check on the plane aerodynamically speaking, something easy to mess up that i might haven't noticed?(beside rebuilding the wing)

That battery is WAY to big, so I would replace that.....Make sure if you get that motor that you ESC can handle the 42A is draws.

 

[Riki10]

okey, I'll drop the battery. I'll let you know when i will have tested it again. Btw I've checked your channel and your plane are really cool, especially the p-38. The fact that you used I smaller capacity battery for a plane with two motors makes me ralize how comically oversized was mine

 

[quorneng]

Riki10
Whilst I applaud your perseverance to build your first RC plane perhaps you can now see the advantage in buying a kit which will have recommended RC components or even something "ready to fly".
First it probably will fly, the only question is whether you have the skill but more important it will introduce you to a workable set of RC components.

Although a competent model builder I bought a "ready to fly" trainer to get a start into modern RC.
Now after 13 years I can build whatever plane takes my fancy and it stands a good chance of flying well.

 

[Riki10]

Riki10
Whilst I applaud your perseverance to build your first RC plane perhaps you can now see the advantage in buying a kit which will have recommended RC components or even something "ready to fly".
First it probably will fly, the only question is whether you have the skill but more important it will introduce you to a workable set of RC components.

Although a competent model builder I bought a "ready to fly" trainer to get a start into modern RC.
Now after 13 years I can build whatever plane takes my fancy and it stands a good chance of flying well.

You are probably right. I'always been the kind of persone who likes more building something than using it. I tought that building one would have been the best way to learn something new. Now i know that I've underestimated its challenges.This model have already taught me a lot of things, now i have a basic understandig of how lift get generated from the wings and i know the name of many more plane parts. The flight controller has been the most interesting part, understanding how a gyro works and how to use it's data to know what's happening to the plane has been a real challenge. Moreover has been a way to test what i was learning in Uni. I know that from the previus post sounds like i was getting fed up of breking the plane. I don't mind breaking it as long as i'm learning something. Crashing it because i don't know how to fly would already been a huge success. I was getting tired because i couldn't get what's wrong with it, especially after the latest crash were the only thing that i understood was that something was wrong.

 

[Houndpup Rc]

You are probably right. I'always been the kind of persone who likes more building something than using it. I tought that building one would have been the best way to learn something new. Now i know that I've underestimated its challenges.This model have already taught me a lot of things, now i have a basic understandig of how lift get generated from the wings and i know the name of many more plane parts. The flight controller has been the most interesting part, understanding how a gyro works and how to use it's data to know what's happening to the plane has been a real challenge. Moreover has been a way to test what i was learning in Uni. I know that from the previus post sounds like i was getting fed up of breking the plane. I don't mind breaking it as long as i'm learning something. Crashing it because i don't know how to fly would already been a huge success. I was getting tired because i couldn't get what's wrong with it, especially after the latest crash were the only thing that i understood was that something was wrong.

I think you can get it too fly! just get a smaller battery and a better motor and you will have taken a big step forward! I agree, building is the funnest part of the process! Don't feel bad about these mistakes, we all make them when are first starting out. By the way what size servos are you running?

 

[Houndpup Rc]

okey, I'll drop the battery. I'll let you know when i will have tested it again. Btw I've checked your channel and your plane are really cool, especially the p-38. The fact that you used I smaller capacity battery for a plane with two motors makes me ralize how comically oversized was mine

Thanks! Yeah its just a little oversized, and for sure is one of your problems. (That size battery is more for something with a 60" wing span.)

 

[Riki10]

I think you can get it too fly! just get a smaller battery and a better motor and you will have taken a big step forward! I agree, building is the funnest part of the process! Don't feel bad about these mistakes, we all make them when are first starting out. By the way what size servos are you running?

Let's hope so, the model is really good looking it just misses the ability that defines an airplane 🤣. I am using some 9g servos, the classical blu ones used in arduino projects. I had a bunch of them laying around, they gets the job done. About the servos i was wondering something about the ailerons and elevator. I keep the ailerons flush with the wing in theirneutral position,same thing with the elevators. Is it okey? Moreover I've read on the model document that is recomended a throw between 12° and 16°, it means that the elevator should go up 12° and down -12° so a complete movement of 24° or 12° is already the complete movement? Aither way it seems a really small movement but the second one is almost imperceptible

 

[quorneng]

Riki10
The throws required on any control surfaces depends on their size relative to the size of the plane and what manoeuvres you want it to be able to do.
Over control is a real problem for learner pilots. This can be minimised by having dual rates (set by a switch) and/or expo movement (little initial surface movement with the stick but increasing with stick deflection). All set up by menu adjustments on the transmitter. There are also situations were the surface movement is asymmetric, usually more up than down.
The issue is understanding what adjustment will make an appropriate improvement resulting in the plane becoming easier to fly.
For a ready designed plane there will be recommended control throws that have been found best suited for the initial flights.
There are no "standard" maximum control deflections as there are so many variables involved but in general less rather than more to start with.
I hope this helps.

 

[Riki10]

Riki10
The throws required on any control surfaces depends on their size relative to the size of the plane and what manoeuvres you want it to be able to do.
Over control is a real problem for learner pilots. This can be minimised by having dual rates (set by a switch) and/or expo movement (little initial surface movement for with the stick but increasing with stick deflection) all set up by menu adjustments on the transmitter. There are also situations were the surface movement is asymmetric, usually more up than down.
The issue is understanding what adjustment will make an appropriate improvement resulting in the plane becoming easier to fly.
For a ready designed plane there will be recommended control throws that have been found best suited for the initial flights.
There are no "standard" maximum control deflections as there are so many variables involved but in general less rather than more to start with.
I hope this helps.

Thanks, got it. I will leave them alone for now. When it will fly i will focus on them

 

[Riki10]

In the meantime I've weighted the plane without the battery, 270grams, so the new battery should bring me close to 370. I've weighted my motor,the new one should be 10grams lighter. I think I will fix the wing and then I will try to drop some more weight. I' ll let you know

 

[Houndpup Rc]

In the meantime I've weighted the plane without the battery, 270grams, so the new battery should bring me close to 370. I've weighted my motor,the new one should be 10grams lighter. I think I will fix the wing and then I will try to drop some more weight. I' ll let you know

Cool! What motor did you get?
BTW what transmitter do you have?

 

[Riki10]

Cool! What motor did you get?
BTW what transmitter do you have?

In the end i bought the motor you suggested me, i found a site that would have delivered it in five days. The transmitter is really intresting, I decided that I wanted to use my phone to fly the plane. I started with the integrated wifi antenna of my microcontroller but the range was not optimale. So i modified a old wifi router. Basically i drop it in the middle of the field and i get enough coverage to clear it. I tried my best to compress the size of the packet sent from the phone to the plane so latency is minimum and, given that i am sanding packet as fast as i can, i don't care about losing some of them. The comunication from the plane to the phone is a little bit slower but they are just data like battery voltage and gyro reading, i don't care, worst case scenario the attitude indicatoron my phone lag a little. In the future i will consider putting a nrf24 transmitter to use a physical joystick, i don't like much the feedback of the touchscreen

 

[Riki10]

Do you think is a bad idead to cut a hole in the under side of the wings, near the fuselage and cover them with paper? The wings are pretty wide there i don't think the overall rigidity would be compromised. Moreover the upper sheet of foam would still be intact. I can't think of other ways to reduce the weight. When i rebuilt it the second time I've already made evrything non structural out of paper. Or you think it's better to live with the extra weight?