Quad couldn't lift off the ground

Started by payamrastogi, April 11, 2017, 08:00:02 PM

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payamrastogi

I built this quad following the instructions on [dronepi](http://www.instructables.com/id/The-Drone-Pi/)
but get couldn't get it off the ground. At full throttle, it is moving sideways not able to lift completely off the ground.

Can someone please point me out the problem or guide me to the right direction
Below are the specifications for the quad.

**Turnigy D3530/14 1100KV Brushless Outrunner Motor**

Spec.
* Battery: 2~4 Cell /7.4~14.8V
* RPM: 1100kv
* Max current: 22A
* No load current: 1.6A
* Max power: 315W
* Internal resistance: 0.077 ohm
* Weight: 73g (including connectors)
* Diameter of shaft: 5mm
* Dimensions: 35x30m
* Prop size: 7.4V/12x6 14.8V/8x4
* Max thrust: 1100g
* Total Weight (4 X 73g): 292g

**Turnigy 3300mAh 3S 30C Lipo Pac**
Spec.
* Minimum Capacity: 3300mAh
* Configuration: 3S1P / 11.1v / 3Cell
* Constant Discharge: 30C
* Peak Discharge (10sec): 40C
* Pack Weight: 297g
* Pack Size: 137 x 43 x 22mm
* Charge Plug: JST-XH
* Discharge plug: 4mm Bullet-connector
* Total Weight(1 X 297g): 297g


**450 X - Mode Alien Multicopter Quadcopter Frame**
Spec.
* Package weight: 0.655 kg
* Package size (L x W x H): 37.00 x 18.00 x 9.00 cm / 14.57 x 7.09 x 3.54 inches
* Total Weight (1 X 655g) = 655g


**Hobbyking Slowfly Propeller 10x4.5 Blue (60g)**

**HobbyKing 30A ESC 3A UBEC**
Spec.
* Constant Current: 30A
* Burst Current: 40A
* Battery: 2-4S Lipoly / 5-12s NiXX
* BEC: 5v / 3A
* Motor Type: Sensorless Brushless
* Size: 54 x 26 11mm
* Weight: 32g
* Programming Functions:
* Battery Type: Lipo /NiXX
* Brake: On / Off
* Voltage Protection: Low / Mid / High
* Protection mode: Reduce power / Cut off power
* Timing: Auto / High / Low
* Startup: Fast / Normal / Soft
* PWM Frequency: 8k / 16k
* Helicopter mode: Off / 5sec / 15sec (Start up delay)
* Total Weight(4 X 32g): 128g

**Multiwii and Megapirate AIO Flight Controller w/FTDI (ATmega 2560) V2.0**
[multiwii](https://hobbyking.com/en_us/multiwii-and-megapirate-aio-flight-controller-w-ftdi-atmega-2560-v2-0.html)


**Total Weight ~ 1432g**

Balakrishna Reddy


Swapnil

Even though the total weight isn't the main problem, it's still on the higher side. A 450 sized quad shouldn't weigh more than 1200 grams if you want good overall flight characteristics.

The frame you are using is too heavy for a 450 quad. All the 450 frames I have weigh around 250 - 300 grams including landing gear. Also, try a 2200 to 2600 mAh 3S LiPo first if you have access to one.

rahulandy27

Have you checked the propellers? Are they cw and ccw ? Is their orientation correct?

payamrastogi

Quote from: Balakrishna Reddy on April 12, 2017, 12:01:52 AM
Try to Post a video.
Will Try to do that

Quote from: Swapnil on April 12, 2017, 07:05:07 AM
Even though the total weight isn't the main problem, it's still on the higher side. A 450 sized quad shouldn't weigh more than 1200 grams if you want good overall flight characteristics.

The frame you are using is too heavy for a 450 quad. All the 450 frames I have weigh around 250 - 300 grams including landing gear. Also, try a 2200 to 2600 mAh 3S LiPo first if you have access to one.

I don't have one, have to get it from HobbyKing. Do you think it would be a good choice to replace the frame too?

Quote from: rahulandy27 on April 12, 2017, 09:01:58 AM
Have you checked the propellers? Are they cw and ccw? Is their orientation correct?
Yes, the propellers are CW and CCW, and they are mounted accordingly. But since you pointed it out, I will check it again.

Thanks all. Will be back with an update.

Swapnil

Quote from: payamrastogi on April 12, 2017, 06:46:04 PM
I don't have one, have to get it from HobbyKing. Do you think it would be a good choice to replace the frame too?

Yes. Get one weighing 400 grams or lighter.

The max. rated thrust of 1100 grams for those motors is not with 10x4.5 props. Try 10x5.


payamrastogi

Quote from: Swapnil on April 12, 2017, 07:00:53 PM
Yes. Get one weighing 400 grams or lighter.

The max. rated thrust of 1100 grams for those motors is not with 10x4.5 props. Try 10x5.



Hey Swapnil, Thanks for your prompt reply.
Can you also tell me or provide me with the link for determining the right propeller and motor combination? Is there any guide or tutorial available for that?

Swapnil

The motor+prop combo depends on the use (FPV, aerial photography, fun-flying etc).

payamrastogi

This is my first quad project, So it is just for hovering/fun flying [Just wanted to get it lift off the ground]
I was following the below tutorial on Instructables
http://www.instructables.com/id/The-Drone-Pi/

payamrastogi


K K Iyer

#10
@payamrastogi,

Looks like:
1. Too heavy. Leave that for the moment. Tackle it later.
2. Nose heavy. Move the lipo back an inch or two. You can do this now.

I think then it WILL lift off and hover.
Best of luck.
Regards

Swapnil

After watching the video, it's clear that the quad isn't properly balanced. The center of mass should lie at (or close to) the center of gravity in the x-y plane for the FC to work properly. So, like Iyer sir said, move your Lipo to the center and your problem should be solved. The section where you have placed the LiPo is for FPV gear.

Quote from: payamrastogi on April 12, 2017, 08:33:23 PM
This is my first quad project, So it is just for hovering/fun flying [Just wanted to get it lift off the ground]
I was following the below tutorial on Instructables
http://www.instructables.com/id/The-Drone-Pi/

Then your current setup should be okay.

A good rule of thumb is that at half throttle each motor should provide at least 30% thrust for a stable hover. Say, you are getting a max. thrust of 4000 grams with your current setup. Then, for a half-throttle hover, the total weight shouldn't be more than 1200 grams.

If you are not going to be adding any payload, there's no need to change anything.

saikat

apply some forward and right trim from your transmitter and try to takeoff.
if required give some down elevator while taking off

Comet

Hi Payam, I had a similar problem with my 450 quad and your problem seems similar. However, while you are using the MultiWii controller I was using the APM 2.5 with ArduPilot running. My problem was in the throttle setting wherein for some odd reason my Max Throttle was set to a value of 90 instead of 1000. Check the throttle parameters in your controller and set it correctly if required.

payamrastogi

#14
Quote from: K K Iyer on April 12, 2017, 10:00:31 PM
@payamrastogi,

Looks like:
1. Too heavy. Leave that for the moment. Tackle it later.
2. Nose heavy. Move the lipo back an inch or two. You can do this now.

I think then it WILL lift off and hover.
Best of luck.
Regards

I tried to move the battery to all the way to the centre, however, the problem still persists.


Quote from: saikat on April 13, 2017, 05:20:24 AM
apply some forward and right trim from your transmitter and try to takeoff.
if required give some down elevator while taking off

I'm totally new to this domain, do you have any tutorial/guide. I'm using FlySky FS-i6 transmitter.

Quote from: Comet on April 13, 2017, 09:59:09 PM
Hi Payam, I had a similar problem with my 450 quad and your problem seems similar. However, while you are using the MultiWii controller I was using the APM 2.5 with ArduPilot running. My problem was in the throttle setting wherein for some odd reason my Max Throttle was set to a value of 90 instead of 1000. Check the throttle parameters in your controller and set it correctly if required.


Let me check it. Will update you guys with a new video

Thanks All

sankhasubhra11

Check the motors carefully.I think one of your motor is damaged.For more thrust try a2212dji motors 980kv or 980kv marspower motor.

payamrastogi

Quote from: sankhasubhra11 on April 14, 2017, 07:50:26 PM
Check the motors carefully.I think one of your motor is damaged.For more thrust try a2212dji motors 980kv or 980kv marspower motor.

I had already checked the motors they were fine, but I guess it has got something todo with ESC.

sankhasubhra11


payamrastogi

Quote from: sankhasubhra11 on April 14, 2017, 08:19:34 PM
Which ESC you are using?



**HobbyKing 30A ESC 3A UBEC**
Spec.
* Constant Current: 30A
* Burst Current: 40A
* Battery: 2-4S Lipoly / 5-12s NiXX
* BEC: 5v / 3A
* Motor Type: Sensorless Brushless
* Size: 54 x 26 11mm
* Weight: 32g
* Programming Functions:
* Battery Type: Lipo /NiXX
* Brake: On / Off
* Voltage Protection: Low / Mid / High
* Protection mode: Reduce power / Cut off power
* Timing: Auto / High / Low
* Startup: Fast / Normal / Soft
* PWM Frequency: 8k / 16k
* Helicopter mode: Off / 5sec / 15sec (Start up delay)
* Total Weight(4 X 32g): 128g

Imperial fire

Jeez....interesting to see people say that move the battery a little to get it to fly..lol..
Its a freaking quad....program it correctly and it won't matter ...there is a reason why quads have flight controllers....
As long as the c.g is between the props it shouldn't affect its capacity to ' take off' for the least.....
And if u r gonna make a quad that weighs 1300 gm on a 1200 gm thrust setup..... Goodluck flying it...

Imperial fire

Work on the f.c bro.. That's all the difference between a quad that can do crazy stunts and a quad that struggles to hold its position in air...never mind not taking off.
Although if I were you I wouldn't feel too bad....I've seen guys at IIT struggle to get their quads fly ... :giggle: :giggle:

Swapnil

#21
Quote from: Imperial fire on April 15, 2017, 09:05:17 AM
Jeez....interesting to see people say that move the battery a little to get it to fly..lol..
...
As long as the c.g is between the props it shouldn't affect its capacity to ' take off' for the least.....

Ah, there's never a shortage of geniuses like you, mate.

Do us all a favor and stop spreading your ignorance.

rastsaurabh

What Mr. Fire is saying is correct to a certain extend and i agree to him in a case where the quad is flying perfectly and we place battery off CG on it .

But you cannot ignore the point of CG on a non maiden quad where trims, throttle, tuning, ESC, motors are not confirmed to work in sync.

For such a quad you need to first make everything possible to ideal setup.

regds
saurabh


Imperial fire

Yes its true that if the c.g is not balanced ..the motors on one side will have to work harder than the motors on other side...and trims etc maybe needed and some turns/ rolls maybe be easier than the counter turn/ roll...
But what I am saying is that a quad with proper settings and calibration on f.c  and gyro.....will fly....irrespective of slight offset c.g.
It will not fly organic ...but will fly for sure.
@ swapnil...ignorance nahi bhai...dekha hai...friends ke quads pe dekha hai...they put camera weighing 200g in the front and 'bomb dropper 'weighing 400+ gm at the back and if u ask em about c.g¿?? They twll me its not an airplane...😂
Just giving my 2+ cents...coz I know how frustrating it is when ur bird doesn't fly....

Swapnil

@Imperial fire

No, what you said specifically was "As long as the c.g is between the props it shouldn't affect its capacity to ' take off' for the least"

Did you see the posted specs? Did you see the posted video?

1] The center of mass of the 300g battery is more than 4 inches away from the CG. That's a lot of torque to overcome.

2] The maximum difference in RPM between axially opposite motors is limited by the FC during take-off. In cases like these, the motors on the heavier side will give a max. thrust of 50% each while the ones on the other end will give 5% to 10%. Assuming the Turnigy motors give a max. thrust of 1000 grams each, the max. total thrust produced in the above scenario will never cross 1200 grams.


Quote from: Imperial fire on April 15, 2017, 10:51:05 AM
...dekha hai...

So you base your advice on 'dekha hai'? This is where one would use the words 'jeez' and 'lol'! But, you chose to use them to disprove advice given by multiple senior members and make your unsubstantiated nonsense sound like 'years of experience'.