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Permalink Reply by Vernon Barry on May 2, 2012 at 11:08am

You have the basics but you need to know a few things about the system.

ArduCopter 3DR-B Frame + Motors Kit (Motor AC2836-358, 880Kv with 12X45 EPP Style) 

So on the page for those motors, they each draw up to 20Amps full load for a combined total of 4x20=80Amps

Battery ratings have a C# for constant discharge rate, meaning take the battery capacity in mAh times the C rating equals the max safe disharge current. Just like driving your car at it's rated MAX HP is likely to reduce the lifespan, the same is true with a battery. Recommended battery for that combo is 3000mAh to 5000mAh 11.1V 3 cell and since most are at least 25-30C rated these days even a 3000mAh battery is rated at 3A times 25C = 75Amps rated. While the 3000mah is marginal for your setup, 75Amps is less than what the motors could draw 80Amps, typical hovering and flying currents aren't normally maxed out. Further, let's say normal is 13Amps per motor flying times 4 is 52 Amps total draw. A 52Ah battery (5200mAh) in theory could fly for about an hour, with smaller batteries lasting less under the same basic formula.

Manufacturers don't really have great reliability or credibility in C ratings over 30C meaning I wouldn't buy a 40C battery and expect it to have great lifespan if pushed to 40C all the time. It's not like there is a lot of independent testing to keep these cheap battery companies in line. Most any battery these days is rated at 20C so we pretty much assume they all will hit that spec and a lot are rated at 30C as well and that makes it a little more reliable, but not foolproof, thus you really want to size the capacity big enough to not be hitting the C rating at max power.

Don't forget a good battery charger with balancer and leads, and most require a power supply providing strong 4-30Amps of 12-18V power.

 

That all said, you want to get telemetry. You will greatly appreciate that mission planner can log your flight and you can more easily make setting changes using the newer and better telemetry radios. I consider this a required option IMHO. Further, in the US, use the 915MHz kits.

I'd also get the sonar at some point, but it's not required initially and honestly, the new baromter in the APM is really good. As of right now, the optical flow doesn't work with APM 2 so don't even bother looking. ALL the other sensors are on APM2.0 so pretty much, you are set with what's the best options available today.

 

You basic setup will work very good, I have the exact same frame, motors and APM 2.0.

You might read the other newb thread and learn from mistakes in that review during your build. EXPENSIVE lessons were learned and hopefully will save you the same problems.

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Permalink Reply by Cedric F on May 3, 2012 at 11:30pm

Thanks Vernon.  You response was a great help.

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DistributorPermalink Reply by UnmannedTechShop.co.uk on May 15, 2012 at 1:31pm

A nice place to see all the stuff you need for arducopter can be found on the page what do i need for arducopter

 

It includes a list of the required parts, and also the optional extras 

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