Samstag, 4. August 2012

TBS Discovery

Tech Specs:
Naza Flightcontrol with GPS addon (this is a must for FPV!)
Weight: 1,3kg (FPV ready; without battery and GoPro)
Motors: T-Motor MN3110 -15 780KV  (new, installed Mar/14)
Props: Graupner e-Prop 10x5
Battery: 4cell 3300-5000mah high C-Rating!
Battery bay measurements: 3-3,5cm high, max 5cm width, 14-15cm long
Power Consumption: avg. 319mah / minute  (using 3600mah 4cell  I get save 8 mins)

Current Naza Settings (28.2.14):
Basic Gains: P:100 R:100 Y:100 V:100  (since new motors and 10" Props had to move back to 100%)
   Atti Gains: P:100 R:100
Mounting GPS: -10cm,   Current Firmware: 4.02
Radio: FrSky X8R,   Expo and DR for Manual Mode 25% Expo, 70% rate

TBS Store - also links to buildlogs!
FPV-Lab Forums (Trappy writes here!)
Speedstep23s Disco Tipps video
Loosing height on left turn? SOLUTION
Sebastians (Globeflight) intro to the GPS mode
you can also buy DJI stuff at

Build Pics:

Things learned from my build:
Earplug Mod also works great on TBS Disco! Maybe some vibs but they don't get on the 720p60 mode of the gopro. 1080p30 works but has some jello.
GPS is very nice addon - gives you confidence while flying far out!
I already did a RTH test - and learned that TO DISABLE the autolanding you have to switch the mode switch to manual and back to GPS mode!!!!

Dampening of VideoTX is important. I used a foam piece - a simple 3m tape alone wasnt enough.
Unfortunately I burnt one VideoTX and the TBS Core on my build (switched red with black cable...) - so I had to leave this away for now - sorry Trappy!
Important: I had two motors "stuttering" and found a simple cause: I accidentally used 10mm screws to fasten the motors. This didn't "feel" wrong when spinning the motors by hand - but it caused this problem. As soon as I changed back to the original 8mm long screws - it was fine! I ran into the stuttering again by using Roxxy motors. I think the DJI ESCs are quite picky on what motor they support.
Looks like the Naza's barometer is sensitive to sunlight: it causes height drop if you turn into the sunlight. Prevent this by adding some black tape or foam on the left side of the box. See my video

Further tuning:
I ran through 4 types of motors:

First the stock DJI 920kv (150 Watt) Motors: they are not bad - only my sample had two with bad bearings - they turned harder - got hotter - I didn't like that.

Then my old Roxxy 2728/34 (110watt, 750kV): quite efficient with 10x4,5 Props - but this combo has vibrations (at least for me - maybe one can balance this properly and get good results). Power would have been OK. Another Issue: I had them "stutter" on my DJI ESCs - so they are maybe not compatible.

Last but not least RCTimer 2830/14 750kV (185 watt):
These are the selection from TeamWhiteLama - and sold from Trappy (TBS). They are just great, cheap and seem to run very smooth. (I had them for 200 flights and then switched as a precaution against failure to more expensive T-Motors (see above))

Tests on 4cell:
DJI Motors with 8x4,5 DJI Props: 17amps @ hover
Roxxy Motors with 10x4,5 Mikrokopter Props: 15amps @ hover (same battery)

Battery selection? I decided to use the Turnigy 4cell 3600mah 30c
(available in DE warehouse - ordered this tuesday afternoon, got them today!)
All batteries are in good shape and have around 400gr with connector. First one of them was used today. Work well and fit perfect in the bay! Power is more than sufficient for nice ascension! It's definitly worth to use 4Cells on the TBS! 3Cell isn't as stable...
Update: currently a SLS (Stefans Liposhop) 5000mah 4cell fits in perfectly and gives nice flighttime extra (10-12mins).