Setting up the Governor on mini VBar

Notes from setting up the mini VBar governor on a flybarless T-Rex 450 RC helicopter


Setting up the mini VBar governor for the first time can be a little confusing. Here are some notes from my setup experience with a flybarless T-Rex 450 electric helicopter.

 

mini VBar with two phase sensor plugs

mini VBar with with two phase sensor plugs. + and - power plug into RX C. The sensor wire goes to the top pin of RX A.

 

Helicopter Setup:

Heli: Align T-Rex 450 Pro

ESC: BL35X (Align Stock)

Motor: BL430SP (Align stock)

Phase sensor: Hyperion RDU Phase Tachometer HP-EM2-TACHBL from allerc.com

Pinion: 13-tooth

Head: Align FBL

 

VBar Setup:

Gov I tab:

Preset channel from receiver: 1

Output socket on VBar: RX B

Gov II tab:

Max Headspeed: 3000

Gear ratio: 11.538 (150/13)

Sensor configuration: 3 (That is six "poles"--the six magnets around the inside of the motor's "can," not to be confused with the nine stator windings--divided by 2)

(The next two settings are probably very transmitter-dependent and included just for reference.)

Motor off: -92% <-- the level at which the motor *just* starts when you turn off Throttle Hold with the throttle in IU.

Motor on: 81% <-- there's a clearly audible change at 80%. At 81% it's going all out (seems low though...)

 

Autorotation bailout: I haven't enabled this yet, but I've been experimenting with it. The electric governor setup pages at www.vstabi.info/en say that if you set Throttle Hold to anywhere from -90 to 0, the auto bailout feature will be enabled. Setting my DX6i Throttle Hold to 16% (which gives -73% in VBar's "Output socket on VBar") appears to be the threshold of consitently "arming" autorotation bailout. Setting the DX6i Throttle Hold to 20% throttle arms Autorotation Bailout reliably which I can tell because the governor ramps up to full speed in 2 seconds instead of 10).

 

Main menu:

Gain: 30%

 

Transmitter setup:

Calculate how much the headspeed changes for your Max Headspeed setting with this calculator, or just just divide the max headspeed value by 50 to get the change increment for each 1% throttle change:

3000 RPM Max Headspeed / 50 = 60 RPM headspeed change for each 1% throttle change.

IU Throttle: 97% <-- This gives a "requested RPM" of 2820 RPM.

Normal Throttle: 92% <--This gives 2520 RPM.

 

Transmitter throttle % and resulting headspeed with VBar gov "Max headspeed" set to 3000

% Throttle   RPM
100.0   3000
99.0   2940
98.0   2880
97.0   2820
96.0   2760
95.0   2700
94.0   2640
93.0   2580
92.0   2520
91.0   2460
90.0   2400

 

Requested headspeed goes all the way to 0 at 50% throttle. (Note, however, that efficiency is best when a motor is running close to its maximum speed.)

0% to 50% throttle: 0 RPM

 

Align BL 35X ESC programming:

Brake: Disabled

Timing: Mid-timing

Battery protection: High cutoff

Aircraft: Airplane

Throttle response speed: High

Voltage: 6 v

 

Notes:

  • The throttle is LIVE as soon as you select "Electric."
  • The setup was behaving so strangely that I went back and read the instructions. You have to hit Reset after you select "Electric." You really do!
  • At one point in the setup you control the throttle with the collective stick. Make sure your pitch is set linearly from 0 to 100 or you will get weird results.

 



                                                                                                          
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