MultiWii / NAZE / SP Racing F3 APM 2.5 / 2.6 on 6S setup

[BatCam]

Hey guys, have been successfully running a TBS discovery on APM 2.5 and now building a SkyJib X4 Heavy with an APM 2.6 module. I was wonder if anyone has experimented with the best solution for powering the unit on a 6S setup?

The options I'm considering are:

Running a 2S lipo and BEC, buck converter, or supplied PSU for the APM unit, and 6S for everything else (Herk III ESC and Gimbal)

or

Running a breakout circuit and keep everything directly from 6S.

Anyone got some advice on this or other options? Electrical understanding is basic, but learning more everyday...

Cheers,
Cam

 

[dazzab]

Oh boy! Another Droidworx down under. I really think we need to have a meet up somewhere. I'm also please to see more people giving the APM a go on them. I had a chat with one of the developers just yesterday about some very interesting GPS concepts and I can tell you that the APM platform is just getting better and better. A bit tricky at times but full of features.

For what it's worth I'm tapping power off the PDB to a BEC that supplies 5V to power the APM. Then I use an Attopilot current/voltage sensor connected to the APM to monitor the power. I know people who like to power the flight electronics separately from the main power, but I think that's just a lot of extra complexity and wiring that's not needed.

 

[nicwilke]

Oh boy! Another Droidworx down under. I really think we need to have a meet up somewhere. I'm also please to see more people giving the APM a go on them. I had a chat with one of the developers just yesterday about some very interesting GPS concepts and I can tell you that the APM platform is just getting better and better. A bit tricky at times but full of features.

For what it's worth I'm tapping power off the PDB to a BEC that supplies 5V to power the APM. Then I use an Attopilot current/voltage sensor connected to the APM to monitor the power. I know people who like to power the flight electronics separately from the main power, but I think that's just a lot of extra complexity and wiring that's not needed.

Count me in for a Droidworx meetup. :thumbup:

 

[BatCam]

Thanks Dazzab, good to hear another opinion on the power conundrum! A meet-up would be great, I'm still a little while away from air worthyness, a few more weeks and I will be close. If it's before the end of the snow season I might swing by canberra for a rip around

 

[kcallagmy]

I am building a fairly heavy lift hexa and using 6S battery to power motors only. I am using a separate 3S battery with a APM power unit to power the APM as well as power the video tx, and hooked up to two BEC's to power the gimbal servos. I just wanted to try and isolate as much as possible the APM power source from the main batteries in fear of any sort of power issues from 6S side causing APM failure/brownout.

 

[Bartman]

Batcam,

I went through similar trials last year and did a few different things to deliver 3S power to my flight control. The first thing I did was to tap into the balance connector for 3S power but the traces in the PCB are very fragile and would burn out if too much power went through them. Also, the balance wires are rated at a few amps at 1S power but not that much when 11.1V is going through them.

In the end, I've made a separate wire harness for a separate 3S pack and it is turned on and off with a switch. It's worked out great and a single 1500mah pack lasts a really long time, multiple flights. The 3S voltage displays on my transmitter since it is also powering my receiver (Hitec).

 

[Silverburn]

+1 - I do this too, with a slight modifier, in that I use a single 3S 1300 with the 3DR power module to run all the electronics.

Only downside to this approach is the compassmot process is throttle-based; you won't get as accurate flight as you do with the current method. I have a compassmot of 4%, but still can't tune out a "yaw bounce". I would still consider getting a current sensor inline with the 6S, if only to allow you to run a current-based compassmot.