skyjib 8 heavylift gain setting?

[nileshafilms]

Hi guys, last week i mounted red epic with 32mm master prime and ND filter on gremsy h14 gimbal.. but while take off throttle went almost 80-85% and couldn't fly it for long time max 4min.. and it was responding very slow with moving around.. can anyone pls let me know if i should increase gains?
Skyjib 8 configuration
KDE 3520 400kv motors
16x5 tigermotors prop
40A tigermotor ESC
Powerhungry board
dji A2
2x16000 tattu batteries. .

kindly let me know about increasing gains..
thanks in advance. .

 

[dazzab]

My SkyJib Lite has a TOW of 9.5Kg so its much smaller than yours. I do run the gains about 10-20 higher than stock on a Wookong. I doubt very much you'll get reasonable flight from a copter that heavy. You really need to get that hover rate down. I haven't heard of using batteries that large so you might consider going to a smaller size which could save you some weight. Did you do any eCalc calculation on this ? There are others who fly SkyJib with Red here on the forums that will be able to give you more specific advice.

 

[violetwolf]

I would strongly advise against flying at all with anything over 60% hover throttle. Even 60% is pushing your luck.

 

[Motopreserve]

The gains should not have any effect on the throttle % needed to hoist that rig. Like mentioned already - you really need to figure out the weight issue before you get airborne again. Especially given the value of the payload.

Without doing any research or calculations, I'd say the 16" props with those motors might not be providing nearly the thrust you need.

What's the AUW of the rig with the full payload?

 

[Old Man]

Try flying it using only one of those batteries and observe performance differences. I agree with the others, changing gains is not going to help correct the underlying problem.

 

[maxwelltub]

Using only one of the batteries might have too much lag in delivering power?

 

[Motopreserve]

If my calculations are correct a single battery should provide 240A, no?

 

[maxwelltub]

That's right on paper, but in practice I've seen some voltage on osd when using one 16ah pulse on a similar setup.

 

[Pumpkinguy]

I think you are way under powered. Other guys are hinting at that but I figure no point in beating around the bush.

If I trusted KDE data to be accurate, 1310 grams per motor @ 50% brings you to a safe AUW of about 10kg. MAX

I suspect you are way over that.

 

[Motopreserve]

That's right on paper, but in practice I've seen some voltage on osd when using one 16ah pulse on a similar setup.

Agreed. This is only a spec based assumption. But it seems the draw would be in the 160A range. Have you seen sag with that much headroom? If so, my calls/plans have been thwarted!

 

[Old Man]

I think you are way under powered. Other guys are hinting at that but I figure no point in beating around the bush.

If I trusted KDE data to be accurate, 1310 grams per motor @ 50% brings you to a safe AUW of about 10kg. MAX

I suspect you are way over that.

Exactly! Under powered or over weight. Pick either one and you would be right.

 

[nileshafilms]

Thanks everyone for suggestions. .
i appreciate that..!
I will try to cut down weight by using lighter lenses like canon..

 

[Pumpkinguy]

I don't think the lens is gonna help.

Let's do some math here.

You have 4kg's just in batteries. 2.5kg for camera (no lens) 2.5kg for gimbal (no battery)
You are basically at your max weight without even considering things like the aircraft itself. Lol. Motors, electronics, landing gear etc.

You need a new rig if you want to carry a red. At the very least you need a complete over haul to the power train. New motors and esc's. Cheers.