RC India

RC Models => Multirotors => Topic started by: abhilash_172 on December 07, 2012, 09:52:01 PM



Title: My first quad build log
Post by: abhilash_172 on December 07, 2012, 09:52:01 PM
hello friends, i made my first quad using wiimotionplus and adxl 345 sensors.i used multiwii code.Thanks to rcindia,it has been a great learning resource for me, especially the "Multirotors" section.
quad details:
850kv motors from rchobbyaddict
30 amp mystery cloud esc's from rcbharat
zippy flightmax 4000mah 40c battery
10x4.5 props
Frame:used aluminium square tubes for arms and acrylic 5mm sheet for centre plates


Title: Re: My first quad build log
Post by: abhilash_172 on December 07, 2012, 09:58:18 PM
i made a sensor sheild to arduino uno


Title: Re: My first quad build log
Post by: abhilash_172 on December 07, 2012, 10:02:33 PM
first i tested sensors on breadboard and finally soldered them to arduino sheild


Title: Re: My first quad build log
Post by: abhilash_172 on December 07, 2012, 10:11:49 PM
i used rubber grip in between motor mount and aluminium arm to reduce vibrations.i attached yellow colour smiley balls as landing gear.mounted the battery downside of acrylic using velcro battery strap


Title: Re: My first quad build log
Post by: abhilash_172 on December 07, 2012, 10:15:36 PM
after putting everything,final design of quad


Title: Re: My first quad build log
Post by: RcBharat on December 07, 2012, 10:39:01 PM
Very good Abhilash

Good to know that it's flying at last

Try uploading some flight videos.

Thanks
Sai Krishna
www.rcbharat.com


Title: Re: My first quad build log
Post by: abhilash_172 on December 07, 2012, 10:53:14 PM
my quad AUW is 1300 gms.lifts off at 50% throttle.i didn't try kk board,but multiwii is so much stable.i kept pid stock values as default in multiwii code,i didn't adjust any trims on transmitter,quad is stable in air with little drift.but i can control it.
And i want to share my esc's story with everyone.i hope beginners will be careful in selecting ESC for their quad
(1)  first i bought turnigy trust 45 amp esc ,as the motor rating is around 35 amps.then i tested them with code.they are not supporting 490hz pwm refresh rate.All my excitement gone with that.
(2) then i searched on internet a lot,solution was to decrease the refresh rate.then quad was working.i made some test flights with lower refresh rate.i was very happy flying it.
(3) to increse the refresh rate,i flashed them with simonk firmware.i damaged the sbec circuit of one esc.i disconnected the 5v and ground wire from that esc.it was ok.then the ultimate disaster happened,i connected one other esc with wrong polarity.i saw magic smoke after that.i didn't buy spare esc also.total two esc's damaged.
(4) to put an end to this mystery,i bought mystery cloud 30 amp esc's from rcbharat.after that everything is good.now i am enjoying flying my quad but i got a big punch in my pocket.it was all because of my stupid mistakes.


Title: Re: My first quad build log
Post by: abhilash_172 on December 07, 2012, 10:56:52 PM
thanks rcbharat,soon i will post flight videos also


Title: Re: My first quad build log
Post by: abhilash_172 on December 07, 2012, 11:01:46 PM
friends,if you are using multiwii for your quad,then make sure you buy esc's which have higher refresh rates or change them to simonk firmware.it is written in multiwii FAQ webpage also


Title: Re: My first quad build log
Post by: satyagupta on December 08, 2012, 08:29:15 AM
Nice build abhilash, post some flight videos...


Title: Re: My first quad build log
Post by: rajathv8 on December 08, 2012, 09:20:46 AM
Hello Abhilash.
1. How did you reduce the refresh rate as mentioned in point 2? Why did you need "490hz pwm" refresh rate?
2. If the BEC is damaged you need to disconnect the supply (red) wire only. The ground(black) is needed to pass the signal along. Please correct me if im wrong.

The collection of boards looks beautiful!! Happy flying. :)

PS: Please post flight videos.


Title: Re: My first quad build log
Post by: abhilash_172 on December 08, 2012, 10:16:21 AM
hello rajathv,
in multiwii,refresh rate code is 490 hz.it is written in faq.i saw a similar kind of problem in multiwii forum.one person made changes to ouput.pde file to decrease the refresh rate.i am using that code instead of original code.
and i think esc's are already connected to ground by power supply,so no need to connect ground wire.that esc is working only with signal wire.
@satyagupta thanks,actually i don't have camera to shoot the video.but i will try to post the flight videos.