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Futaba GV-1 Governor 9ZAP / 9ZHP Set Up
Nigel Brackley

Over the past couple of years, Futaba have developed some new items specifically for the helicopter brigade. First the G 501 Piezo Gyro, then came the GV-1 Rotor Governor and recently, the GY 501 AVCS Piezo Gyro with heading lock facility. As I have been using a mixture of these items regularly during the past few years, many people keep asking, how does that work?, what does it do? and can I make it work any easier? Therefore the following article is a beginning in trying to unfold the mysteries of these items, and to show that given the information, they are not as complicated as they first seem.
I have been using Futaba GV-1 governors quite extensively since they were released, both in models for film work and my own. I can honestly say that any new model I build now, automatically gets a governor fitted. This is not because I cannot get them to fly right, far from it, its because I would rather be flying them then playing around with them in the workshop or on the field. Therefore the GV-1 Governor is the first item to be looked into, the unit has been available for a couple of years now and hopefully this will show some methods of how to operate it to its full capability. Although not the only unit on the market and cer-tainly not the first, it is a very easy item to set up following the supplied instruction booklet. It is strange however, that the easiest way of programming the unit is not covered in the booklet, so this will be the con-text of this article.

Do we really need one?
First of all, the governor allows the user to select a rotor speed between 1000 - 2100 rpm, for any given flight condition. We can use a speed of 1250 - 1400 rpm for example as an FAI style hovering speed, then for out and out aerobatics we can run a speed of around 1850 ~ 2100 rpm. It definitely simplifies any throttle set-up, as throttle curves are no longer required, apart from one basic non governed setting. In practice, when we hover or fly around at around 1350 rpm or lower, the rotor speed is very smooth and se-date. As we increase the collective to climb, the engine opens up as required to maintain the rpm under load and the model just goes up with a slightly deeper engine note but no noticeable increase in rotor speed. The same is true of the higher rpm settings, when in aerobatics mode at say 1850 ish, try doing some slow rolls with smooth collective inputs. As the model rolls over, the rpm will be maintained as a constant rather than possible overspeedi!
ng. The other saving grace of this system, is that the torque reaction is virtually zero, with the rotor rpm now being held constant at all of the collective range. At the end of the day, the governor lets you, the flyer, dictate exactly how you want your machine to respond and fly.

What makes this one different?
The processor is housed in a small box, approximately half the size of a standard receiver. On the front face is a Liquid Crystal Display, which projects all of the required information as we set it up. Under-neath the display is an adjuster for the contrast, to allow for bright or dull days and four small push button switches. These allow us to scroll through the menu and adjust, activate or inhibit the internal settings. Any other settings are then adjusted from the transmitter.

The unit operates with a single small magnet, that is to be installed in the underside of the fan as-sembly. A small sensor is mounted on a bracket off of the engine mount. Two brackets are supplied, one for 30 size machines and one for 60 size. The sensor is triggered on every revolution by the magnet and sends a signal to the control amplifier, which then decides what action to take, so as to drive the throttle servo to its desired position to maintain whatever pre-set rpm has been selected. As for accuracy, the system can maintain the rotor speed within 1% of the required rpm ( i.e. 15 rpm @ 1500 rpm ), which is more than good enough, and ideally with a good fast servo on the throttle, any time delay is so small and negligible, it is very easy to live with. A fast servo is not essential but is preferred to help it keep up with the output informa-tion, the quicker the servo reacts to a change in position, the less it will eventually have to move. The biggest advant!
age over its rivals is that it senses at engine speed, not rotor speed, which gives a higher trigger count of feedback to the control amplifier. For example, if we selected a speed of 1650 rpm on the rotor with a gear ratio of 9.3 : 1, the governor processor calculates what the engine should be turning, i.e. 1650rpm x 9.3 = 15345 rpm on the engine. It will then adjust the position of the throttle servo until the engine speed matches what is required. Because of the way this system operates, obtaining the quoted 1% accuracy is much easier, as the rpm tolerance is larger. It is also made easier for us, as we only need to fix one magnet, not three as with some other units, which are then required to be placed accurately at 120 degrees spacing.
As in all cases, it does not matter what type of helicopter you fly or what style of flying you are in to, but to be able get the best possible results, you need to have some understanding of what you want to get out of your equipment first! Obviously the GV-1 unit is intended for Futaba equipment, 9ZAP / 9ZHP or FF8 / FF8 Super. The FF8 Super now contains a Governor set up in the new software. I have no doubt that the unit could be made to work with other brands of R/C, but at present, I have no first-hand knowledge with these other systems.
The following information covers set-ups for the Futaba 9 ZAP / 9ZHP ( both original & WC models). Here we can allocate a switch to turn the governor on and off, which enables the use of normal and idle up throttle curves, but at the same time, by throwing a switch, the governor can be activated in any of the flight conditions. The downside, is that this method requires an additional channel for on / off switch acti-vation. Alternatively, the unit can be activated by using the program mixing function ( PMX ). In this way, each fight condition will have its own mix value, in this case an offset, which will then represent its own rpm setting. As the switching in this method is performed in the mix function, it no longer requires any addi-tional channels. I find this to be the most universal way of operating the governor, and will therefore con-centrate on this method in part 1 of this series. As for part 2, I shall continue with the set-up details for using extern!
al switching and using the ATV values. Then lastly, in part 3 we will look at the different ways to set-up and operate the GY 501 AVCS Piezo Gyro.

All of the required settings and adjustments are made, in the governor control amplifier and in the transmitter programming. There are many different ways to accomplish the same results, so to start with lets look at how we want the model to be set-up.............

For an example, lets look at the following as a possible set-up.........

1, Normal Hover - non governed / normal throttle action.
2, 1st Speed - governed hover ( 1400 rpm ).
3, 2nd Speed - governed mid speed ( 1650 rpm ).
4, 3rd Speed - governed high speed ( 1850 rpm ).
5, 3D - non governed V throttle curve.
6, Hold - non governed / normal hold setting.

NOTE If you do not require anyone of the conditions shown in the sample list above, replace it or them, with the next highest condition, i.e. if the 3D condition is not required, replace it with the Hold condition and therfore only 5 conditions will be in use instead of the 6 shown.

First Steps
Before we get stuck into the governor itself, we have some other ground work to complete first. We need to set up a condition which enables us to have the engine under normal control so that we can start it; this condition can also be used for a non governed hovering / flying set-up. The second condition would be used for a governed version of the hovering set up ( IDLE 1 ). The third condition for general, mid speed flying around or mild aerobatics ( IDLE 2 ). The fourth, for all other aerobatics( IDLE 3 ). The fifth would have the governor turned off with a V curve throttle, instead ( 3 D ). The 6th would be for the Throttle Hold.
In the case of the 9ZAP / 9ZHP, the highest condition has authority over its lower ones; therefore, if we select the 3D set up (condition 5 ), it will respond directly over the other conditions with only the HOLD( condition 6 ) having authority over the 3D condition. Alternately, you could activate the mid speed setting ( condition 3 ), where the governor will automatically take over, without having to go through the normal hover ( condition 1 ) or governed hover settings ( condition 2 ). Again, the 3D and HOLD ( conditions 5 & 6 ) would have authority over the previous conditions 1 to 4.

This following set-up example uses the governor as described above for 6 conditions, Normal, Speed 1, Speed 2, Speed 3, V Curve, Hold, all by using the program mix function ( PMX) and the AUX. 1 channel to ac-tivate the governor rpm.

Before any settings can be made for the governor, the transmitter needs to be set up for switch allocation and program mixing for its operation. Therefore the first step is to select the flight conditions that will be required and allocate them to the required switches..............

  • First, activate the conditions CSL Sw A Normal Hover no governor
    Sw A Idle 1 Hover with governor ( 1st Speed )
    Sw C Idle 2 2nd speed
    Sw C Idle 3 3rd speed
    Sw H 3D V-curve
    Sw B Hold
  • Select an auxiliary channel for governor switching, i.e. AUX 1, set control to NULL in FNC.
  • Speed switching ( Norm) 1, Select Normal Hover condition.
  • Select PMX ( program mixing )
  • Select MIX 1
  • Select ACTive.
  • Select Type of mix - OFS
  • Select switch - Sw A - ON
  • Select channel to be mixed - AUX. 1
  • Select NEXT ( next page)
  • Set value : -100
  • Speed switching ( 1st Speed)
  • Select Idle 1 condition.
  • Select PMX ( program mixing )
  • Select MIX 1
  • Select ACTive.
  • Select Type of mix - OFS
  • Select switch - Sw A - ON
  • Select channel to be mixed - AUX. 1
  • Select NEXT ( next page)
  • Set value : -100 ( initial value )
  • Speed switching ( 2nd Speed) 1, Select Idle 2 condition.
  • Select PMX ( program mixing )
  • Select MIX 1
  • Select ACTive.
  • Select Type of mix - OFS
  • Select switch - Sw C - ON
  • Select channel to be mixed - AUX. 1
  • Select NEXT ( next page)
  • Set value : -100 ( initial value )
  • Speed switching ( 3rd Speed) 1, Select Idle 3 condition.
  • Select PMX ( program mixing )
  • Select MIX 1
  • Select ACTive.
  • Select Type of mix - OFS
  • Select switch - Sw C - ON
  • Select channel to be mixed - AUX. 1
  • Select NEXT ( next page)
  • Set value : +100
  • 3D switching ( V-Curve) 1, Select 3D condition.
  • Select PMX ( program mixing )
  • Select MIX 1
  • Select ACTive.
  • Select Type of mix - OFS
  • Select switch - Sw H - ON
  • Select channel to be mixed - AUX. 1
  • Select NEXT ( next page)
  • Set value : - 100
  • The V-Curve can be set in the throttle curve at a later stage.
  • Speed switching ( Hold) 1, Select Hold condition.
  • Select PMX ( program mixing )
  • Select MIX 1
  • Select ACTive.
  • Select Type of mix - OFS
  • Select switch - Sw B - ON
  • Select channel to be mixed - AUX. 1
  • Select NEXT ( next page)
  • Set value : - 100

Now that you have the conditions and mixing set-up, connect the governor to the receiver as shown below.

  • Receiver Connections Gov. Throttle into CHANNEL 3
  • Gov. RPM into AUX. 1
  • Gov. On/Off - NOT USED.
  • Connect, sensor & throttle servo ( without connecting throttle linkage)
  • Switch on system.
  • Before procceding any further, now is a good time to check the basic data, i.e. sensor feed back and gear ratio.
  • Scroll through governor data pad to : SENsor - check for a reading of 60 or more ( 97 maximum ).
  • Scroll through governor data pad to : GRt - set to gear ratio of ENGINE : ROTOR ( 3:1 ~ 15:1 )

At this point you may have to REVerse the action of AUX. 1 for ROTOR SPEED 1 to be in the same switch postion as IDLE 1

  • The throttle travel needs to be adjusted for full stroke, with values as close to 100% - 100% ( i.e. linear ), not forgetting to ACTivate the ENGINE CUT at the same time.
    No throttle curves are required, any the 3D V-Curve will be set later on.
  • Scroll through governor data pad to : ROTOR SPEED 1 ~ press - data key until display shows - RSL-OFF ( Tx. program mix value of -100% )
  • Select IDLE 3 switch on Tx. Adjust HIGHEST required speed with + / - data key for 1850 ( Tx. program mix value of + 100% ) RPM range 0 ~ 2100rpm is available between values of -100% ~ +100%
  • Select IDLE 1 switch on Tx. Adjust value in Tx. program mix ( +51 ), to obtain 1st required rpm speed setting ( i.e. 1400 ).
  • Select IDLE 2 switch on Tx. Adjust value in Tx. program mix ( + 78 ), to obtain 2nd required rpm speed setting ( i.e. 1650)
  • Select 3D switch on Tx. Display should read RSL- OFF( Tx. program mix value of 100%)
  • Select HOLD switch on Tx. Display should read RSL- OFF( Tx. program mix value of 100%)
  • Scroll through governor data pad to : StSw
  • Select THROTTLE CURVE in Tx. Adjust curve in NORMAL to required set up.
  • Select IDLE 1 switch on Tx. Lower Tx. throttle to lowest position.
  • Select LOW on Tx. screen.
  • Adjust value ( 60% ) until governor display changes to ON.
  • Select IDLE 2 switch on Tx. Lower Tx. throttle to lowest position.
  • Select LOW on Tx. screen.
  • Adjust value ( 60% ) until governor display changes to ON
  • Select IDLE 3 switch on Tx. Lower Tx. throttle to lowest position.
  • Select LOW on Tx. screen.
  • Adjust value ( 60% ) until governor display changes to ON

Note : In the event of a sensor or magnet failure, the low throttle value will act as a
mild IDLE UP feature, as it has raised the bottom point of the throttle curve.

  • Select 3D switch on Tx. Adjust V-Curve throttle to your own desired settings.
  • Scroll through governor data pad to: SWCd - to check switch conditions.
  • Turn all switches to OFF position on Tx.
  • Normal Hover - display should show OFF
  • Select 1st Speed - display should show ON
  • Select 2nd Speed - display should show ON
  • Select 3rd Speed - display should show ON
  • Select 3D - display should show OFF
  • Select HOLD - display should show OFF
  • Scroll through governor data pad to : LMT - throttle range limits
  • Flashing IDLE - position throttle stick to LOW , press +/- key Flashing HIGH - position throttle stick to HIGH , press +/- key
  • Flashing STOP - position throttle stick to LOW inc. ENGINE CUT switch to ON , press +/- key.
  • At this point you can also activate the GvOf position if required. This allows the governor to be disengaged when the throttle stick is moved past a pre-set position, and allow the throttle to open to its corresponding stick position. As soon as the throttle stick is moved back below the pre-set point, the governor will automatically re-engage again. This action will not occur on pre set speeds of less than 1600 rpm ( therefore, if the rpm selected on IDLE 1 is higher than 1599 rpm, the selected speed range will not be disengaged).
  • Scroll through governor keypad to : GOV OFF Initially set to INHibit
  • Press - KEY to obtain stick switching position
  • Throttle stick range equate to 0% ~ 100%

Example: Setting the value at 97% would mean that by leaning on the stick at full collective, the governor would be disengaged, no longer maintaining any pre set RPM and the throttle travelling to MAXIMUM.

  • At this point, I would also suggest that when test flying / setting up is finished and throttle stroke and trim settings are finalised, it would be wise to repeat stage 27 ( throttle LMT settings ), as this
    will re-establish the relationship of the throttle stick range.
  • Failsafe Settings.

If you are using the governor with a PPM receiver, then the battery failsafe B/FS will ensure that if the receiver battery were to fail, then the governor would switch off and shut the engine down to a
pre-set position.

  • Scroll through governor keypad to : B/FS - initially set to INHibit
  • To select ACTive press + / - key.
  • To select the fail safe position press + key again.
  • Now set throttle stick to desired position & press + / - key.
  • The throttle position is then memorised.

If you are using a PCM receiver, in addition to the above on board battery failsafe, it would be wise to activate the failsafe function in the transmitter. Select AUX. 1 to failsafe operation with all of the condition switches in the off or normal position. This will enable the governor to be de-activated in the case of any problems and will return control to the throttle stick ( NORMAL HOVER ).

Additional Features
Remaining functions of the governor display include the ability to change the display from showing rotor rpm or engine rpm . This way, by viewing this function, you can check on the maximum engine or rotor speeds reached during flight. This must be done before switching off the radio system, once switched off, any cur-rent value will be reset.
Another major feature is the ability to add a fuel mixture servo into the mixture output from the governor control amplifier. This has been designed to be used with the OS 60D Auto Mix Carb, which is available from OS for the 61 SX / RX WC engine. This unit is without any manual needle valve at all, the fuel calibra-tion being taken care of by a programmable 9 point curve. When correctly setup, this then allows the extact amount of metered fuel to be available for each position on the 9 point needle curve as the throttle opens and closes. The system does work well, but takes quite a bit of time to perfect. As a side note, the fuel mixture function can now be found as a standard feature on the WC model of the 9ZAP / 9ZHP and the FF8 Super transmitters.

Featured Link!
RC Helicopter Web
A site by John Vugts, very comprehensive, well done site. Lots of good information on getting start...

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