First flight with my DJI F550 and Aeroxcraft landing gear with my new Sony Nex5n

Bella7821

Member
Here's quick test video of my DJI F550 with the awesome Aeroxcraft landing gear and my new Sony Nex5n mounted to it.
I don't even have a gimbal and this thing is pretty solid and vibration free.
I'm very impressed with the hexacopter and Aeroxcraft's landing gear.
With this much weight (just about 6 pounds) the motors did get pretty hot (140 degrees)
I think I'll need better motors if I keep this much weight, especially if I ever add a gimbal.

http://youtu.be/zGxWzg2BCEA
 

Dewster

Member
Nice video! I have a Sony Nex 5n too. I bought it for my hexa, but I think that the weight is just too much for my setup. I'm using Avroto 2814/11s and DJI 30a esc. I think the total weight of my craft, landing gear, battery (6000 mah just over 1 pound) and motors are just too much. What's the rating on your esc? I think 40amp would be a better setup to keep things cool. The Aerocraft landing gear looks pretty hot! That's the only thing missing on the F550: a good landing gear/gimble option.
 



Bella7821

Member
Was using NAZA, now I have a WKM that came in tonight. But playing with the Z axis, CG was 2.5mm under the bottom plate
 

How did you calculate?

How did you calculate the Z axis CG? I do understand that you are using a landing gear that is attached to the bottom board and a 6000 mAh 4S Lipo?
 

Bella7821

Member
I have a 4500 4s battery, not 6k.
It took me a week to understand the Z axis, I just couldn't wrap my head around it and a bunch of people from RC Groups helped me to understand. I'll try to explain and if you don't get it call me and I'll explain over the phone.
You hang the copter on a string (tie the string to the motor, the arm, or whatever. just try to get close to the end.
It doesn't matter which arm and at different tie points it will hang differently but that doesn't matter, the Z axis will always be the same. (But whenever you change something that adds/ lessens weight you have to re-do it.
While you're hanging it or holding it, have someone take a photo (try to get it in the position in my photo).
Then upload your photo to Microsoft Paint and draw a line from the string STRAIGHT down ad another through the center of the copter (if your copter is balanced) and where those 2 points meet will be the Z axis.
Read the manual to get a positive or negative number.
Here are my readings now.
The IMU Z axis is -1cm and the GPS is -5cm, my Z axis was 1cm below the bottom plate.
Now without the landing gear my Z axis was 3cm for the IMU and -1cm on the GPS.
My GPS X axis is 7cm (and I get full GPS lock in less than a minute mounted on the top plate.


newCGwithgear.jpg


CG.jpg


IMAG2813.jpg
 
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Now, THAT is an explaination... :).. Thank you very much, especially for the pics. I'll re-check my values with this guide.
 

btw. did you experience any electro-magnetic interferences with the compass? (e.g. gearing/yaws). I've noticed that you don't use a pole for the gps module at all.
 

vinnygogo

Member
that method only works when the photo is taken perfectly level and straight( wich, for instance, your last pic is not;)) you can do it way easyer. just point the nose up(like on the pictures) and try to balance it on you fingers somewhere on the landing gear/copter. at some point, it wel stay level en not fall forward or back. that is you z point;)
 

Kilby

Active Member
btw. did you experience any electro-magnetic interferences with the compass? (e.g. gearing/yaws). I've noticed that you don't use a pole for the gps module at all.

I was just about to ask the same question. I've built a very simular craft and I would love to get away from having a tall GPS mount sticking off the top.

7234573294_657b865dde_z.jpg
 


Bella7821

Member
This is the 2nd F550 and this one is brand new and I've only hovered in the backyard with not a very clear view of the sky.
I also hovered before I attached the landing gear and the battery was mounted on top so it was close to the GPS and it still got a full lock in less than a minute.
I tested it out on the pole, then said "what the heck, I'll see how the signal is with the GPS just sitting on the top plate and it worked perfect so I left it like that. I'd hate to lose it in a crash so the lower the better for me.

Since it works perfect in my tiny backyard with a horrible view of the sky, I'm assuming it's going to work even better in an open area.
Maybe I just got lucky and got a really good GPS.

GPSlocation.jpg
 

I was just about to ask the same question. I've built a very simular craft and I would love to get away from having a tall GPS mount sticking off the top.

Wow, that's a damn long pole ;-) Did you ever try a shorter one? Seems to be ultra long.
 

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