This is the part of the project I had concerns about. The Ultrix has differential thrust whereas one can vary the thrust between the two motors via the rudder stick. This has proven a very popular feature, so including it in my 2S project was a must.

I modified a Vtail mixer by removing the black JR servo plugs (input end) and soldered 1.00 micro plugs to the existing solder points, and then soldered 1.25 sockets to the male pins to route to the ESCs.

My first try ran all 3 servo wires (red, yellow, black) of the receiver's THROTTLE and RUDDER channels to the mixer and then just the yellow signal wires from mixer to the ESCs. But only one or the other ESC would run, or one ran with the throttle stick at full throttle and the other at zero throttle. Reversing channels in the TX did nothing to fix it.

Then I gave it some thought and guessed that the mixer must need the black ground wire as well as the yellow to complete a signal wire circuit between mixer and ESCs. The signal ground was not needed when the mixer was not in the system and the yellow wire ran directly between the RX and ESCs.

This video shows the SECOND time I tried it. The first try with high hopes but some doubts was successful, so I immediately set up my camera to record this demo to show my friends. That huge wall I ran up against several days ago when my first mixer tests failed and I thought the 2S Ultrix may not get differential thrust after all has been knocked down! UltraUltrix is moving ahead!


Happy Flying!