Thursday, December 28, 2017

Zeta FX-79 Buffalo Build - Wiring plan

Zeta FX-79 Buffalo Build - Wiring plan


The stock configurations for the FX-79 seem to recommend running with 3s lipos, so that's what I'm planning to do.  I'll be using two 5000 mah batteries in parallel.    My Flight Controller is rated up to 5s, as far as I can tell on the forums, so I have the option of upgrading later if I wish.

The Omnibus F4 Pro V2 comes with an onboard 3 amp BEC.  However, as I read the forums, I understand that it can get rather warm.  As a precaution, I'm planning to run very little through the onboard BEC.

Power Plan

  • Direct from batteries
    • Flight controller - rated to 5s (I think).
    • Runcam and VTX (through a filter).  Both are rated up to 6s.
    • ESC (via the Flight Controller for current measuring)
  • BEC on Flight Controller
    • GPS
    • Uart inverter
  • External BEC
    • Servos
    • Receiver
  • External BEC (auxiliary port)
    • Lights or special effects
I roughed out a wire plan on my office whiteboard.



About Club24A


There are known problems with this board with regards to reporting accurate current if VCC is jumpered into the Camera or VTX pins.  It's known as "Club24A" in the forums.  I'm avoiding that problem entirely by not using the onboard jumper to apply power to the RAM pins.  I'm actually hijacking the RAM pins for another purpose (RSSI).  I'm providing the power to the camera and VTX via the wiring harness, apart from the Omnibus board, so I do not expect any of the Club24A issues.

Riser pins


Since I'm providing power to most of the external devices via the external BEC rather than through the FC, it's led to a rather convoluted wiring harness.  While the FC provides 3 pins in most places, for powered servo cables, I'm generally using just the signal wire, and drawing power from my external BEC.  I decided to solder wires directly onto the Flight Controller and terminate with female servo connectors.  This makes the flight controller a bit of a hassle to wire up, but with care, it should be alright. 

I'm planning to use extension cables everywhere, so that the FC can be removed for calibration or reprogramming if necessary.  Also, being the most convoluted part of the build, it should be fairly easy to transplant, if the plane crashes badly enough that I need to replace the foam.

Here's the flight controller wiring, about 3/4 done.  I'll update this picture when it's complete.  Note the heavy cables which lead to the batteries and ESC.  The servo cables patch into other cables to provide power.



Monday, December 25, 2017

Zeta FX-79 Buffalo Build - Preliminaries

Zeta FX-79 Buffalo Build



My wife bought me a Zeta FX-79 Buffalo flying wing for Christmas.  I'll be chronicling the build in this blog post.  My motivation for this plane was to have an FPV platform to use for balloon "Search and Rescue" operations.  I'd like to have an FPV camera, and a higher resolution camera for post-flight analysis.  I'd also like to be able to fly my Kenwood TH-D72A radio as an airborne APRS digipeater platform.  Since my trackers are very low power (10mw or so), the hope is that an airborne digipeater might be helpful in recovery operations.

I purchased the fittings from a variety of sources.  The Bill of Materials follows. 


I'll be doing the build with the Omnibus F4 Pro V2 flight controller, which includes an OSD and can relay Smartport Telemetry back to my Tanaris Plus transmitter.

In future posts, I'll document the build process and initial flights.