BeagleBone Blue Quad Inverted Motors Not Lifting

ArduCopter Copter 3.5
1

Hi,

I’m building a 180mm quad with BeagleBone Blue -

  • 180mm frame
  • 1306 4000KV DYS motors
  • 1600mAh 20-30C/ 2Cell 7.4V
  • RotoX 3040T 3inch Blade

I have mounted the BeagleBone on the top and the motors are at the bottom (inverted). Since there was not enough space for mounting it on the top along with the BeagleBone. I have inverted the props too.

https://drive.google.com/open?id=1iyDsUQ3GZwzTF7DDwJqoivXn-Ox_Ycki

Note - the FC is not upside down, only the motors are. However, the drone is not lifting even at full throttle. It is blowing the air downwards but not lifting.

Any suggestions?

2

The propeller is mounted in a wrong way.

3

As lucamax said, the propellers must be right side up, even for inverted motors. With the props upside down, they will be spinning with the trailing edge first, so they won’t produce much lift.

4

Looks to me that your props are mounted correctly as you already knew. The problem is your battery. You are obviosly not developing enough thrust with a 2 cell battery. I found a crude performance chart for this motor and it shows 3 or 4 cells.

DYS%201306%20motor
DYS 1306 motor.PNG714×666 156 KB

You need to weigh the copter with out the battery on a digital balance.
Pick a 3 or 4 cell battery and see were you are on the chart. you should have as a minimum 2 times the all up weight at 100 %. So with a 3 cell bat the maximum is 247g x 4, 988g / 2 = 494g. So 494 g copter + battery is the maximum weight to fly safely. Most FPV mini quads have a much higher thrust to weight ratio than 2. With copters its all about thrust and weight. You need to have the data or else waste a lot of time on trail and error.

1 Like
5

Thanks for sharing this. The issue is not the props.

I will measure the weight and check. But I think its worth a shot to put a 3s and try it.
However, I am using a Beaglebone Blue, that has a 2s limit on the battery connector port, I just have to figure out a way to power it.

6

If you do not need to power the Servo Rail, You can use the Bullet Connector = The step down DC/DC converter can work within 7V < VIN < 22V

Otherwise you can make an adaptor to use just 2S from the 3S JST connector, be aware that this can cause an imbalance of the Lipo on long usage.

7

Thank you @ppoirier

So, just to clarify, If I understand it properly

  • Can I take 12v from the 4x1 ESC and build a DC connector and plug it directly into the barrel jack. Is this the bullet connector, you are talking about? or am I missing something?

  • Are there any other pins on the board where we can supply the 12V (VIN)? Because the ESC can output 12V/3A via a BEC (JST) -
    https://oscarliang.com/ctt/uploads/2017/03/DYS-4in1-BLHELI_S-F20A-ESC-2.jpg
    This can help me to avoid using a heavy connector for the DC barrel jack.

  • Or I can directly use the 3s battery and swap the connector to a 2S JST and plug it in. But this might cause the LiPo imbalance on long usage.

I know this sounds like a trivial problem but I just want to be sure that I don’t fry the BBBLue.

8

Can I take 12v from the 4x1 ESC and build a DC connector and plug it directly into the barrel jack. Is this the bullet connector == YES

Are there any other pins on the board where we can supply the 12V (VIN)? Because the ESC can output 12V/3A via a BEC (JST) -

This can help me to avoid using a heavy connector for the DC barrel jack. == NO the Barrel is the only place where you can input 12 Volts

Or I can directly use the 3s battery and swap the connector to a 2S JST and plug it in. But this might cause the LiPo imbalance on long usage. == You nned the 3s JST connector for charging :wink: