RC India

RC Models => Multirotors => Topic started by: kn8alpha on May 26, 2017, 05:12:10 PM



Title: Build: 210 FPV quad with GPS + Baro
Post by: kn8alpha on May 26, 2017, 05:12:10 PM
An experiment of mine has seen the light of day - A 210 FPV flier with GPS and Barometer for altitude/position hold, RTH (return to home) and waypoint capabilities!

Needless to say, this has been a tight build. Here's a pic:

(https://uploads.tapatalk-cdn.com/20170526/cf873c6b7750a12c15a5fe51ba21046f.jpg)

Hardware:
  • 210 carbon fiber frame from Eachine Falcon series
  • MT2204 2300 kv motors
  • Flycolor 20A ESCs
  • Naze32 Acro FC
  • Flysky ia6b receiver
  • External Baro + Magnetometer module
  • Generic UBLOX Neo-6M v2 GPS module
  • AIO 600tvl camera and 200mW VTX (separated cam and VTX)
  • Micro MinimOSD between the cam and VTX
  • PDB with 5V for FC, 12V out and XT60 connector
  • 5V dedicated UBEC for camera and VTX

Software
  • iNav, experimenting with versions

This is my first completed build (have a 450 which is pending testing) and this one's supposed to be a test mule to get some FPV practice and relying on GPS to enable RTH to avoid fly-aways.

I don't have action cam footage yet, but I did record some FPV, here are some freeze frames when quad was in Altitude hold and GPS RTH modes.

(https://uploads.tapatalk-cdn.com/20170526/fde192c7ae172cb74fe9ae3f29e72fb9.jpg)

(https://uploads.tapatalk-cdn.com/20170526/3b286ed7bc51aa79d8726574d3f4ecd0.jpg)

I have selected *the worst* motor and ESC combo and still the quad seems to handle it fine. With some PID tuning and after getting the prop guards removed it might even become a usable quad.

Comments and suggestions welcome!


Title: Re: Build: 210 FPV quad with GPS + Baro
Post by: shlokj on May 26, 2017, 05:21:01 PM
Hi, why don't you use the RS2205 or RS2205S or any 2205 size motor? thatll be much better than mt2204


Title: Re: Re: Build: 210 FPV quad with GPS + Baro
Post by: kn8alpha on May 26, 2017, 11:06:15 PM
Hi, why don't you use the RS2205 or RS2205S or any 2205 size motor? thatll be much better than mt2204
Thanks for the suggestion.. what about Racerstar BR2204? Limited budget so can't afford RS2205 and thus chose whatever I could get easily.

Sent from my ONEPLUS A3003 using Tapatalk


Title: Re: Build: 210 FPV quad with GPS + Baro
Post by: tushar50 on May 27, 2017, 12:19:53 PM
The racerstar br 2205s are also great. They recently also released the br 2306s in 2400kv and 2700kv, the are very powerful and great for fpv racing but will require 30amp esc, they are almost the same price as br2205s.


Title: Re: Build: 210 FPV quad with GPS + Baro
Post by: tushar50 on May 27, 2017, 12:21:04 PM
The racerstar br 2205s 2600kv also produces more thrust than the emax rs2205


Title: Re: Build: 210 FPV quad with GPS + Baro
Post by: shlokj on May 27, 2017, 12:25:36 PM
Tushar,
no the br2205s 2600kv produces only around 700g thrust, while the rs2205 2300kv produces more than 1 kg


Title: Re: Build: 210 FPV quad with GPS + Baro
Post by: tushar50 on May 27, 2017, 12:30:43 PM
It produces around 1150g of thrust and at about 25 amp draw.
below is the video link for racerstar br 2205 2600kv thrust testing.


Title: Re: Build: 210 FPV quad with GPS + Baro
Post by: tushar50 on May 27, 2017, 12:33:46 PM
sorry, the video link is this
https://youtu.be/7nrN3b2jFDY


Title: Re: Build: 210 FPV quad with GPS + Baro
Post by: pixelshooter on May 27, 2017, 01:53:28 PM
Hi. Nice build. What is your experience with the GPS related functions?


Title: Re: Build: 210 FPV quad with GPS + Baro
Post by: kn8alpha on May 31, 2017, 03:50:20 PM
It produces around 1150g of thrust and at about 25 amp draw.
below is the video link for racerstar br 2205 2600kv thrust testing.

I guess that depends on the propeller, as I learnt yesterday.

I did some crazy-scissor-trimming of 5040 tri-blade props to fit this frame and it flies much better now, but noisier. Hovers at 62% throttle.

Also did some PID tuning indoors and the hover is much stable. Next up is tuning outdoors, punch outs and recovery, etc.


Title: Re: Build: 210 FPV quad with GPS + Baro
Post by: kn8alpha on May 31, 2017, 03:57:10 PM
Hi. Nice build. What is your experience with the GPS related functions?

As mentioned in the first post, I've tried iNAV's position hold (2-d horizontal hold) and also Return to home, which self-navigates the quad back to place where armed. Both need GPS and worked well, but I did only 1 trial run and also didn't let the RTH land on it's own (read about some known issues in auto-landing in iNAV 1.7 release notes). For me, I intend to use these only as failsafes, so I'm happy with what I've got so far.

The only problem faced are some slow oscillations while it flew back on its own, but that's should have been solved by the PID tuning. I haven't modified any navigation PIDs.

What do you intend to use GPS for? I would recommend adding and testing Barometer (altitude hold) first before GPS.