Phantom 1.1.1 ToW .. Max Weight and dual batts

[Danny-B-]

Howdy1

I have been contemplating putting dual batteries on etc to squeeze more time from my batteries but have always been put off by the stories you hear about it being sluggish and even that it causes crashes with the typical setup.

Looking at D3weys rear battery cage idea, i think if i ever do try dual batteries it will deffo be a similar setup, rather than the off center COG setups.

Anyway, i currently use Zippy 2800mAh batteries and fully loaded, with battery in, i'm weighing in at 1300g (as accurate as my Mrs scales will go )
plonking another 2800 on top weighs in at an even 1500g which i'm guessing is fairly high ? ... Why is this too high though ? the P2 (which uses the same motors etc) can take off with a similar weight and fly for ages in comparison.

 

[lake_flyer]

if you use P2 props and the default P2 control gains, it will basically fly the same as a P2. You have might a slight difference because of the different weight distribution but it should be just as agile as a P2 with comparable all up weight.

 

[Danny-B-]

Cheers,

What are the default gains for the p2?

 

[lake_flyer]

Cheers,

What are the default gains for the p2?

Don't have the time to hook up my P2 to Naza to check. But even with the default gains of your P1 it should fly ok already. They don't make a tremendous difference.
Do a search on the P2/P2+ forums, you should find the default P2(V+) gains in some threads.

But there's no danger in trying the default P1 gains with P2 blades, they might suit you fine.

 

[lake_flyer]

And one extra advise when you try P2 props:

don't try to take off slowly. Just yank the throttle up and take off quickly. You will see it rises straight and vertically. If you take off too slow it always will try to centre its point of gravity and will kind of tip over, unless you counter it with right stick or managed to get the COG exactly in the middle.

To find the COG is simple.

Take a kitchen scale and place your quad upside down on the scale. You can exactly see the all up weight as well as the COG. If the quad is balanced on it's back on the scale, the COG is in the centre. I made my own battery holders that allow me to move the batteries back or forward until I hit the sweet spot.

 

[lake_flyer]

http://www.phantompilots.com/viewtopic.php?f=29&t=29716&p=272591&hilit=trunking#p272591If you want to have a look at my solution:

 

[Danny-B-]

Thanks again Lake_flyer, yeah that was a thread i started ... i've been debating dual batteries for a while lol
What sorta times do you get from running two ?

 

[lake_flyer]

13 minutes with 2 minutes spare until auto descend, so 15 total with Gopro (no gimbal) + FC40 camera. Around 18 minutes (until auto descend) FC40 camera without Gopro.