Donnerstag, 3. Oktober 2013

Black Snapper (Globe Flight / RC Upgrade)





Tech Specs
Black Snapper, CFK Aluplatte, Landekufen, GPS Halter klappbar, RC Einbaukit
DJI Naza V2 + DJI Iosd mini
Tmotor MT4006 -13 (92gr, 740KV, Max 24A, 250W)
ESC Maytech 30 Amp
Graupner Prop 12x6 + Distanzhüllen
GF Brushless Gimbal + Alexmos Board (FW 2.2b2)

Weight (Full FPV, Gimbal, Gopro3 but without battery): 1,8kg
Folded Size: Width: 25cm    Length: 44cm     approx 13cm height (if GPS is folded down)

Naza Gains
pitch roll yaw vert
Basic 150 150 120 130 
Atti 150 150
Important: make sure your CoG (Center of Gravity) is correct. This means you have to move batteries really far backwards! If you have an hard to control copter (especially if you "yaw" fast) your CoG maybe wrong. Look this vid to see what I mean! With 2 strings I determined the CoG: PIC
I also had problems with non straight motor alignment: PIC

Flighttime: ~14-15min  with 6600mah 4cell
I use 2x Turnigy Nanotech 35C 4S 3300mah  paralell (6600mah)
Powerconsumption:  ca. 370mah / min   the flying weight is 2,4kg!     avg. 19-21Amp

Motors: great - till now I just knew normal little motors that spin 9x5 props and high rpm...
This works but it isn't efficient. You only get around 10min flighttime max...
These motors here have long cables so that the cabling can run in the carbon tubes. This gives nice installation and less air drag under the props. This reduces vibrations!

GimbalI opted to use the Black Snapper Gimbal which comes as an option here. It is controlled by the Alex Mos board which has a good reputation. Build quality is great, Gopro3 fits in well. Motors are good and what they do looks and works like magic! You get really good cam footage - no matter how the copter rocks in the wind - the gopro is straight! I ordered my alexmos board here: buy Alexmos @Austrian Shop who sells a ready soldered board!

best Alexmos Pid Settings
(Juz70 Settings, same Gimbal Motors, different Quad)
       P   I    D   Power at 12V (fed over Balancer-plug)
Roll.  9  0,12  9   88
Pitch. 5  0,14  5   78
Roll invert, 14 Poles,     Sensordirection: Y, right: X
RC settings, PWM       Pitch: RC_Pitch
Min Angle Max Angle
Pitch -35           75           Speed Mode (LPF 4)      Speed 6

Video Guide to Alexmos - good explanation cleared things up for me!
Approx double the P value of Roll vs Pitch!
I gain defines the "speed" to compensate movements...

iOSD Mini: (Mamo-models.com)
Since I use the Gopro Liveout and my view is always straight I cant judge the position of the copter well in the air. You can tell if you "lean" forward or not... So the iOSD is great because it overlays an "artificial" horizont (a dotted line) that shows the copters angle. It also displays pitch and roll as numbers on top.
Great idea: the iOSD has access to all the sensor and GPS data directly from Naza - and doesnt have it's own sensors! This way you get very accurate data. You even see the num of sat's Naza hast, the Flying mode it's in and of course other OSD data like Speed, distance and height...
Most astounding: the home orientation help is really helpful here - rather than a little 3d arrow you get a fluid square floating over your home position (if you're looking in the right direction, otherwise you get a left or right arrow on the border - just see my video and you'll understand...)

Links and Info:
FPV Community Build log (german)
Official Manual from Globe Flight (German, not finished)
Buy this and all other FPV Stuff here Globe-Flight.de!

Buildpics