HEXA H7 - Retractable Legs

[afernan]

I want to show here my new build based in all my previous experiences. I call H7 (my 7th Hexa)

It includes a retractable leg system based in standard servos and some design work. All elememtal parts are 3DPrinted (in standard PLA) using a PRUSA i3.

Using a high stiff frame to minimize vibrations (< 0.5m/s2). This improves A LOT AQ performaces.
Retractable Legs are driven by two (good quality) servos and controlled by a simple Teensy 3.2 code.

Equipment and fw used listed below. Short demo Video here: https://youtu.be/_65N3U7F9sI

Equipment
AQ 6.1 DIMU QUATOS
ESC32 V2 (fw: 2.1.0.6185 )
AQ Fw: v7.1.1858 with WP recording, FolowMe and Tap´n´Go
TMotor 3110/17 + 1240 props.
AUW = 2.2 Kg with 5000mA, 4S

[Astudillo]

Hey this is the machine from the param file Great work Angel!

[Max]

Nice build Angel. I always like the look of your machines, very sturdy looking and everything tucked away neatly. I'm a little concerned about the servo horn/gears on a hard landing though... I destroyed an under-slung camera once because the landing gear couldn't handle the unexpected "landing." Or is there a safety for that?

Anyway, looks great, congrats!

-Max

[afernan]

@Max:
like any other flying machine (big or small) landing is a critical load case. A retractable landing system is always weaker than a fix one, obviously. So double care must be taken when landing and... that´s it!.
But in fact this is not so weak !. I´ve landed (automatic) at more than 1m/s perfectly.
I´ve choose a hi quality servo: Graupner DES 658 full metallic gear, 2x ball bearing in the axis and 6Ncmm torque (45€ each!). I´ve also modified the electronic to get >180º angle.
Main thing is not lo apply any moment to the servo when activated. This is guaranteed by design.

[kinderkram]

Cool machine, Angel!
What is the flight time with a 5000 lipo?

[afernan]

@Norbert:
About 20min.
But I´m changeing to a LIPO 5000mA, 5S battery instead and maybe to 13-4.5 TMotor props. I hope to reach the 30min.

BTW, as you may know i´ve been using LiOn (instead of LiPo) batteries 6000mA, 4S but I´m going back to LiPo standard (30C+) for a number of reasons (too expensive, never got the full 6000mA, max load dropped below 4500mA, etc)

Angel

[afernan]

This is a video demo about WP recording.


@Norbert the system don´t let me do a separated post on "WP recording" so soon wrt this one. Why?

Enjoy
Angel

[kinderkram]

Thx for the video, Angel!

You need to create a Wiki page and submit it to the menu. Just create a page and I will do the rest.
But why not just post on the existing page?

[chschmid]

Hi Angel

What a wonderful machine. Congrats. It flies like a charme.
Did you ever use it with the mission planner and guided mode? I wonder how she would perform.

Cheers
Christof

[afernan]

Hi Christoff: not yet. It´s in my TODO list.
Today I´m testing 5S batteries (with new ESC32 calibrations and motor curves)
Tomorrow, I´ll test the new fw aqv7.1.1871 and just after I´ll test the Mission Planner.

For your information, camera onboard is a Foxeer Legend1 (1080P 60Hz, 100g, 89$). Very good camera!.(http://www.surveilzone.com/Foxeer-Legen ... ens-g-1435). It´s attached directly to the frame without any gimbal/damper.

BTW, I can´t find the xml database for ESC calibrations. I can feed in with new values.
I´ve just tested again the motor curve with 5S (instear 4S) to get AM1, AM2. Theoretically should be quite the same AM1, AM2 values for 4S or 5S; they´re similar, but not the same.
4S was tested with ESC32V3 and
5S with ESC32V2
¿maybe some rmp calcullation discrepancy?