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RC Models => Multirotors => Topic started by: mavquad on June 30, 2014, 07:41:46 AM



Title: quadrotor design configuration
Post by: mavquad on June 30, 2014, 07:41:46 AM
Hi Everyone,

 I have built a quadcopter  with the following configuration:- Emax BL2215/25 1200Kv motor , Hobbyshop 25Amp ESC, 10X4.5 propellers,
3300mAh 3S lipo battery pack with a 30C discharge rate. I have a FlySky 6-channel transmitter and reseiver.

And i am using Arducopter 2.6 as my control board, its a "Plus Configuration".

The total weight of my quad is just 1060 gm as of the motors individually provide 1000 gm of thrust so the actual rating is 1:2, is My quad underweight as referred to the (weight to the thrust ratio).???

I have tried flying it but in many occasions it was flipping backside and front side.

Is it necessary to program the Electronic speed controller using the programming card??.

I will be more than happy if you help me out.

Thank You,

 


Title: Re: quadrotor design configuration
Post by: santhosh-r on June 30, 2014, 08:43:31 AM
Try these ,
Calibrate the accelerometer
Calibrate the ESCs


Title: Re: quadrotor design configuration
Post by: prateek.jolly89 on June 30, 2014, 02:20:55 PM
Check

a) Acclerometer and gyro calibration (artificial horizon is level when u keep ur quad on a level surface). My apm used to occasionally randomly forget the calibration.

b) direction of props

c) APM outputs to the ESCs. Can't think of anything else



Title: Re: quadrotor design configuration
Post by: prateek.jolly89 on June 30, 2014, 02:22:17 PM
Does it rise up, go into some kind of osscilation and then crash, or does it flip as soon as you try to get it off the ground?


Title: Re: quadrotor design configuration
Post by: mavquad on June 30, 2014, 03:05:55 PM

@prateek: this one flips and never takes off, i did accelerometer calibration but there is no option to do gyro calibration in APM.

How to check APM outputs to ESC??

And any suggestion on the weight part.. total thrust of the motors is 4000gm ,my quad weighs 1060gm!!!should i add extra weight???

Thank you



Title: Re: quadrotor design configuration
Post by: SideWinder on June 30, 2014, 04:59:48 PM
Being underweight is alright. It just makes your quad very responsive, but shouldnt flip it. No need to add extra weight.
Gyro is calibrated at the time of arming I guess, so you can only calibrate Acc.
No need of programming card to calibrate esc's, you can do it with your Tx/Rx

Please check the direction of prop rotation and if you have paired the motors correctly to APM
A video/pic of you quad will be helpful.


Title: Re: quadrotor design configuration
Post by: miginstruments on July 01, 2014, 04:12:07 PM
No Issue with the weight. checkout with the motor layout. If u are using X Layout, then check with the motors M1= CW, M2=CCW, M3=CW & M4=CCW, if they are not in the following direction then just flip any of two wires of the motor connected to the ESC. also check out with the Props. P1= R, P2= L, P3 = R, P4 = L. maybe it ll help.


Title: Re: quadrotor design configuration
Post by: veloci on July 01, 2014, 07:19:53 PM
mavquad, is this how you have connected your ESCs to the APM? Same order?
Prop Directions?


Title: Re: quadrotor design configuration
Post by: mavquad on September 22, 2014, 04:59:49 PM
Hi Guys, sorry for late reply I was busy with my MS exams....Thanks for the suggestion you had given.
Here is what I did,

I replaced the ESC to Simon series Emax 25Amp, all the 4 were replaced and
changed the configuration to 'X' , put it in stabilize mode it flew superbly, completely stable by doing the auto tuning.

Now I have bought a U-blox GPS+Compass module from

www.quadkopters.com/product/ublox-6m-gps-with-cover/ (http://)

I have tested the altitude hold successfully, but it tends to drift when there is a wind.

How can I make the quad hold the position when altitude hold is triggered during windy conditions?/

How does the GPS help in position hold(loiter mode as called in Arducopter)? I didn't find any material saying how to configure Loiter + GPS mode for position hold...i may have missed some links though


Title: Re: quadrotor design configuration
Post by: satyagupta on September 22, 2014, 05:22:29 PM
It would always drift in wind. You can increase the PID settings for it to resists the drifting or you can do auto tuning (try this for best result)

http://plane.ardupilot.com/wiki/automatic-tuning-with-autotune/ (http://plane.ardupilot.com/wiki/automatic-tuning-with-autotune/)


Title: Re: quadrotor design configuration
Post by: phanivyas on September 22, 2014, 05:27:55 PM
Altitude Hold will maintain Altitude only not Position. You have to use Loiter mode for holding position (this uses GPS).


Title: Re: quadrotor design configuration
Post by: miginstruments on September 22, 2014, 09:00:20 PM
it will drift in heavy winds don worry bout it. as satya sir has said do some pid settings.


Title: Re: quadrotor design configuration
Post by: v2 eagle on September 22, 2014, 11:23:00 PM
A little out of this dicussion. Always remove your battery from the quad and charge it.
Not in the quad as seen in your photo. quite an expensive experiment.

Ashok.P


Title: Re: quadrotor design configuration
Post by: miginstruments on September 23, 2014, 12:53:26 AM
Nice observation Sir.


Title: Re: quadrotor design configuration
Post by: satyagupta on September 23, 2014, 08:13:40 AM
Not in the quad as seen in your photo. quite an expensive experiment.

that is very good observation and life saver advice...