Hi people. I need help.
I received the package with the quadrocopter DAYA 550.
Two rays of short and two rays of long.
Where to strengthen the long rays and where to fasten the short ones?

I think that should be so.
But I'm not sure, I do not have information.

I'd guess that the long arms go at the front so that the motors are parallel with each other front to back.

It's only a guess though!

There's a quite detailed thread about this frame over on RCGroups: https://www.rcgroups.com/forums/showthre...Quadcopter

(27-Oct-2017, 02:03 PM)unseen Wrote: I'd guess that the long arms go at the front so that the motors are parallel with each other front to back.

It's only a guess though!

Long arms go on the rear

(27-Oct-2017, 02:05 PM)unseen Wrote: There's a quite detailed thread about this frame over on RCGroups: https://www.rcgroups.com/forums/showthre...Quadcopter

Thank you! Very useful link!

(27-Oct-2017, 03:35 PM)RENOV8R Wrote: Long arms go on the rear

This is true, and short arms go forward. 
Thank you very much guys, you helped me a lot.

If I'd looked harder at your picture, it was obvious that the long ones go at the back as the mounting points are further in towards the middle of the frame.

What are the details of your build? Motors, flight controller, ESCs?

(28-Oct-2017, 01:43 PM)RENOV8R Wrote: What are the details of your build?  Motors, flight controller, ESCs?

GARTT ML 3510 600KV
Readytosky 40А ОРТО
1355 Propeller
6000 mAh 50C 4S
APM 2.8 GPS M8

[quote pid='31133' dateline='1509187645']
If I'd looked harder at your picture, it was obvious that the long ones go at the back as the mounting points are further in towards the middle of the frame.  
[/quote]

Logics!

Nice, that setup should be quite sporty for a 550 size craft. 13 " props might be a tight squeeze though, have you test fitted them yet?

(29-Oct-2017, 10:22 PM)RENOV8R Wrote: Nice, that setup should be quite sporty for a 550 size craft.  13 " props might be a tight squeeze though, have you test fitted them yet?

I have no purpose to make a sports model. I need a long flight and a photo.
The propellers were selected for the characteristics of the engines and the dimensions of the DAYA550 frame.
The use of propellers is very different for this frame, from 10" to 15" inches.

I chose the average knowledge of 13". 

If you want to get a longer and more stable flight, then you have to increase your prop size and decrease your KV value of the motors.
Something like 15" and around 400 kV motors.

(30-Oct-2017, 09:58 AM)Dutch Drone Builder Wrote: If you want to get a longer and more stable flight, then you have to increase your prop size and decrease your KV value of the motors.
Something like 15" and around 400 kV motors.

The gains are a lot smaller than you might think.

Given an AUW of 1900g with 13x4.7 props and 600kv motors on 4S, hover time is around 22 minutes.
Changing to 15x4.7 props and 360kv motors on 5S (with an increase in weight to 2067g) gives 26 minutes.

Hardly worth it for four extra minutes in the sky.

I plan to do otherwise.
I want to buy 10,000 mAh batteries and increase the flight time to 35-40 minutes.

(30-Oct-2017, 12:34 PM)gdbr Wrote: I plan to do otherwise.
I want to buy 10,000 mAh batteries and increase the flight time to 35-40 minutes.

Nice try, but it doesn't work that way!

A ballpark weight for your 6000mA/h 4S battery is 644g. For a 10,000mA/h 4S battery, it's more like 1044g.
That extra weight requires more power to lift. You'll get about 27 minutes instead of 22 minutes.

Really long flight times are difficult.

As a rule of thumb, flight time in minutes can be calculated for any multirotor by the following:

Flight time = PD / (1000 * R / gW) * 60

Where:
    PD is the power density of your battery expressed in Watt hours per Kg.
    R is the ratio of the craft's all up weight to the battery weight
    gW is the efficiency of your motor/propeller combination in grammes per Watt at 50% throttle

As an example, let's take the DJI Phantom 2:

The battery is a 5200mA/h 3S which weighs 370g (5.2 Ah) The all up weight is 1250g. The published efficiency of the Phantom's motors and propellers at 50% throttle is 11g per Watt.

PD = 5.2 * 11.1V / 0.37 = 156 Wh/Kg
R = 1250g / 370g = 3.4
gW = 11 g/W

156 / (1000 * 3.4 / 11) * 60 = 30 minutes

Which is pretty much what the Phantom 2 delivers in real life.

More flight time comes from less weight, a higher battery power density and greater propulsion efficiency.