Pirx Seven

The Pirx Seven 7-inch FPV frame

Ladies and gentlemen, I give you Pirx Seven! The 7-inch FPV frame designed in-house to give me, and you obviously, a versatile platform for long-range, cinematic takes and freestyle!

Pirx Seven - 7-inch FPV drone frame

Let's begin with the question: why did I have to design my own frame? There are plenty of good frames out there! True, there are good 7-inch FPV frames, but all of them have some problems: props in the view, very little space inside, thin arms, asymmetrical arms, no place for a huge battery, limited accessories and dozens of other minor things.

Pirx Seven overcomes some of them (creates a few others as well, but let's not shout about it) and truth to be told, it's the best 7-inch frame I own. After all, I designed it to solve problems I was having :)

>> Get it from Armattan Productions <<

Features:

Pirx Seven - 7-inch FPV drone frame

Important notes

Does it fly?

Yeap! Take a look at fly videos:

More about the frame

>> Get it from Armattan Productions <<

Additional, 3D Printed, parts

Armattan Productions does not offer 3D printing service, you will have to print some extra elements:

Note that only an FPV Micro Camera adapter is required. All the rest are optional!

Or you can download all STL files from here: http://bit.ly/2SPdpxW

Reference setup

Settings & Tuning

Pirx Seven reference setup is based on INAV 2.3 as it provides full GPS long-range support as well as very good acro / freestyle flight performance. Below are key settings like mixer, PIDs, filtering and rates that you can copy-paste into INAV CLI instead of manually tuning the drone. Please remember, that if your setup is much different from the reference, you might have to adjust it accordingly.

Mixer

Pirx Seven is an asymmetric frame in a dead cat configuration. It will fly just fine with standard quadcopter mixer, but informing flight controller about the actual motor positions can improve flight performance.

mmix 0  1.000 -0.900  0.800 -1.000
mmix 1  1.000 -1.000 -0.800  1.000
mmix 2  1.000  0.900  0.800  1.000
mmix 3  1.000  1.000 -0.800 -1.000
        

Filters

feature DYNAMIC_FILTERS

set looptime = 500
set gyro_hardware_lpf = 256HZ
set gyro_lpf_hz = 85
set gyro_lpf_type = PT1
set gyro_stage2_lowpass_hz = 150
set dterm_lpf_hz = 90
set use_dterm_fir_filter = OFF
        

PID tuning

set mc_airmode_type = THROTTLE_THRESHOLD

set mc_p_pitch = 45
set mc_i_pitch = 58
set mc_d_pitch = 32
set mc_p_roll = 40
set mc_i_roll = 45
set mc_d_roll = 27
set mc_p_yaw = 75
set mc_i_yaw = 75

set dterm_setpoint_weight =  0.850
set pidsum_limit_yaw = 400
set mc_iterm_relax = RPY
set d_boost_factor =  1.500
set d_boost_max_at_acceleration =  3500.000
set d_boost_gyro_delta_lpf_hz = 50
set antigravity_gain =  2.000
set antigravity_accelerator =  5.000
set rc_yaw_expo = 70
set roll_rate = 75
set pitch_rate = 75
set yaw_rate = 70
        

Other

set min_check = 1050
set max_angle_inclination_rll = 500
set max_angle_inclination_pit = 500
        

>> Get it from Armattan Productions <<