Help! Aileron pushrod not in straight line alignment with servo control-arm linkage-stopper!

[Karthik1130]

Hello all,
I am building the Ben Harber's Baby bugatti 24inch wingspan RC foamboard plane. In this buiding process i am facing the issue as mentioned below:

The central single 9gm SG90 servo for aileron control mounted on the plane, has control arm with linkage-stopper mounted over it. Unfortunately the pushrod coming from the aileron end is not aligning in straight line with the hole in the servo control arm linkage-stopper, instead it has to bend to reach the hole in linkage-stopper. The pushrod seems to bendup once entered into the gap present in the leading edge of wing to reach the servo control arm linkage-stopper and finally, the servo doesn't rotate and jitters.
I see in build pictures from different builders in Baby bugatti thread from Ben Harber's thread showing successful build without any issues.

Could you please help? what changes should i carryout.

Materials used:

1. 5mm foamboard
2. 1mm pushrod
3. 9gm servo
4. Linkage-stopper

 

[Foamforce]

Hello all,
I am building the Ben Harber's Baby bugatti 24inch wingspan RC foamboard plane. In this buiding process i am facing the issue as mentioned below:

The central single 9gm SG90 servo for aileron control mounted on the plane, has control arm with linkage-stopper mounted over it. Unfortunately the pushrod coming from the aileron end is not aligning in straight line with the hole in the servo control arm linkage-stopper, instead it has to bend to reach the hole in linkage-stopper. The pushrod seems to bendup once entered into the gap present in the leading edge of wing to reach the servo control arm linkage-stopper and finally, the servo doesn't rotate and jitters.
I see in build pictures from different builders in Baby bugatti thread from Ben Harber's thread showing successful build without any issues.

Could you please help? what changes should i carryout.

Materials used:

1. 5mm foamboard
2. 1mm pushrod
3. 9gm servo
4. Linkage-stopper

That’s hard to picture. Could you include a photo?

 

[Mr Man]

That’s hard to picture. Could you include a photo?

Agreed

 

[Merv]

....what changes should i carryout...

I agree with the others, a picture would help.

I think you are saying there is a slight misalignment somewhere, which is not uncommon. The solution, put a slight bend in the push rod to make it line up better with the servo. If the alinement issue is more than slight, it will require a different solution. Then we'll definitely need a pic.

If correcting the alinement doesn't fix the servo issue. Then test the servo with nothing attached, it may be bad & need to be replaced.

 

[Bricks]

There are many RC aircraft designed with multiple bends to accommodate the pushrods and servos.

 

[Piotrsko]

Pushrods need to be straight? Crud, then I been doing this wrong all my life. Can you say Z bend?

 

[Karthik1130]

Hello all, thanks for all your suggestion.I found that it's required z-bend for the pushrod to align with the hole in servo linkage stopper,which I am not comfortable with.
Instead I have mounted two servos on either side of wing to control the aileron.

The following were the hardware I used:

1. Motor- Readytosky RS2205 2300KV brushless motor
2. Battery - 3S 1500Mah 30C LiPo
3. Propeller - 5inch dual-blade propeller.
4. ESC- 30A

I took for maiden today, and found that, the motor is lacking power to climb the plane, it couldn't climb and i finally landed it.

Can someone please help and suggest what could be the good motor for the battery and propeller mentioned above, to get good basic aerobatics and for cruising at medium speed?

 

[Mr Man]

Hmm, you should have plenty of power with that motor. First of all, what kind of pitch does that prop have? (Like a 5x?). I also think your battery might be a bit big, a 650-850mah might work a bit better.

 

[Karthik1130]

I am using 5045 dual-blade propeller

 

[Mr Man]

Ok, sounds like you’ve got too heavy of a battery…

 

[Merv]

I am using 5045 dual-blade propeller

Make sure the prop is on the correct way around. The numbers MUST be facing the direction of travel. If the prop is backwards, will only get about 40% of the expected thrust.

 

[Karthik1130]

I ensured the orientation of the propeller was correct, as mentioned before the flight.But i felt like the power was not sufficient when holding the plane by hand,under full throttle for 10seconds.

I found the thrust test data for the 5045 dual-blade propeller online and it was mentioned the maximum thrust of 326gm.

Is this sufficient for this plane?

 

[Merv]

...Is this sufficient for this plane?

How much does your plane weigh, everything included, while it ready to fly?

 

[Merv]

That should be enough thrust to fly about 450g plane.

 

[Karthik1130]

How much does your plane weigh, everything included, while it ready to fly?

I don't have a weigh scale and don't know the weight of the foam fuselage, but I used 5mm thick foamboard.
The following were the remaining total electronics weight details:

• Motor-30gm
• Battery -115gm
• Servo-36gm
• Reciever-15gm
• ESC-23gm
• Propeller-8gm

Total Electronics weight is 219gm except fuselage.

 

[Merv]

...But i felt like the power was not sufficient when holding the plane by hand,under full throttle for 10seconds....

I'm not there to see what you are doing. Unless you used lead lined foamboard, it sounds like the plane should fly.
Just for fun try turning the prop around & see if it will produce more thrust.

Here are some general guidelines that may help.

The amount of thrust needed from the motor & prop depends on how you want to fly. A slow flying trainer, the thrust will need to be 60-80% of the weight of the plane. A typical plane, 80-100%. A war bird or one with a little zip will be 100-150%. A 3D plane will need 150-200% thrust to plane weight.

Watts per pound is another useful guideline. You'll need to weigh the plane and estimate the weight of the motor and battery.

• 50 to 70 watts per pound is the minimum level of power, good for park flyers and lightly loaded slow flyers.
•70 to 90 watts per pound is perfect for trainers and slow-flying aircraft.
•90 to 110 watts per pound is good for fast-flying scale models and some sport aerobatic aircraft.
•110 to 130 watts per pound is what you want for advanced aerobatics and high-speed aircraft.
•130 to 150 watts per pound is needed for lightly loaded 3D models and ducted fans.
•150 to 210+ watts per pound gives unlimited performance for any 3D model.

 

[Merv]

For some reason you are not getting enough power.
New question. Have you calibrated the ESC?

 

[bisco]

is the elevator working properly?

 

[Mr Man]

That's very good question, it might also be very nose heavy.

 

[Karthik1130]

I'm not there to see what you are doing. Unless you used lead lined foamboard, it sounds like the plane should fly.
Just for fun try turning the prop around & see if it will produce more thrust.

Here are some general guidelines that may help.

The amount of thrust needed from the motor & prop depends on how you want to fly. A slow flying trainer, the thrust will need to be 60-80% of the weight of the plane. A typical plane, 80-100%. A war bird or one with a little zip will be 100-150%. A 3D plane will need 150-200% thrust to plane weight.

Watts per pound is another useful guideline. You'll need to weigh the plane and estimate the weight of the motor and battery.

• 50 to 70 watts per pound is the minimum level of power, good for park flyers and lightly loaded slow flyers.
•70 to 90 watts per pound is perfect for trainers and slow-flying aircraft.
•90 to 110 watts per pound is good for fast-flying scale models and some sport aerobatic aircraft.
•110 to 130 watts per pound is what you want for advanced aerobatics and high-speed aircraft.
•130 to 150 watts per pound is needed for lightly loaded 3D models and ducted fans.
•150 to 210+ watts per pound gives unlimited performance for any 3D model.

Thanks for the detailed tip Merv. The following were the checkup i carried out.

1. i did calibrated the esc.
2. i did ensure the elevator was working properly as part of pre-flight checkup.
3. The nose was rather heavy, and i thought it would help in stable flight, but could that be an potential issue?Should the plane be always a little touch nose heavy instead of very heavy?