Mr DJ

Hey Mike,,,

Thank you, Sir...

Mr DJ

Bob_B

My Feedback: (11)

The Jetcat ECU does NOT require the Throttle channel to be reversed, NOT sure about other ECU's!

rhklenke

My Feedback: (24)

I'm sorry, am I missing something or are you really saying that you don't know how to set the throttle failsafe on your 12Z? Have you been flying it on planes without throttle failsafe setup for them?

Bob

jetflyr

My biggest question is this: You do know that the engines have to go to "KILL" after 2 seconds correct?
This has been an AMA rule for several years.....

Greg

ww2birds

My Feedback: (14)

Futaba and JR make a different default choice on how the pulse width varies with stick position. Most RC accessory electronic gear (ECUs, ESCs, etc) are set up assuming the JR default. On a Futaba system you would typically reverse the throttle channel and then set up.

It is not a question of one brand of ECU "requiring" reversing or not, it's an issue with an arbitrary choice that JR and Futaba made differently. It is not a "fault", though clearly it would be easier for all of us if the two mfrs had made the same choice. I don't own a JetCat but if they went the extra mile on their software and allow the "teaching" to work with both JR and Futaba signal conventions, bravo to them! Maybe that's what BE means...after all they are generally acknowledged as having the best ECU software...

To comply with AMA regulations, Greg and Bob are right on the money, it is required that we set up our radios and ECUs (both must be set to work correctly together) so that with 2 seconds of loss of signal (which can be a dead RX, perhaps due to a dead battery ... OR from a failsafe condition), the turbine must shut off.

To set this up correctly is slightly different for JR and Futaba. The JR gang can chime in about the 50 or 75% of throw, multiple bind ritual, I'll cover the Futaba ritual for the 12 and 14 systems, as I practice it. You need to test your own setup by killing the TX and see the turbine shutdown to make sure you are ok ... again this is how I do it, not the "gold standard" .. you have to be confident in your own setup.

1) Set the throttle up for +/- 100 % ATV, and reverse the channel to make it work the same "direction" JR does (per comments above maybe not necessary with JetCat .. but is with Gaspar's FADEC) .. but won't hurt to do this in any case.

2) Teach the ECU your hi/lo throttle and trim settings

3) Go to the ATV screen and set the throttle ATV in the direction of IDLE to -125% (arbitrary, but must be outside the +/-100 range that you just "taught" the ECU .. way "below" stick down/trim down)

4) Go to the FAILSAFE setup screen. Take the stick and trim low, and set the Failsafe at this value (e.g. the button must say "F/S" not "Hold") and push the button to the right to set the failsafe position to this extreme "below idle cutoff" value (the -125%)

5) Go back to ATV and set the throttle back to +/- 100.

Failsafe setup is now Done.

This accomplishes the same thing that the JR ritual does...

BTW, if you want to you can also set up a battery fail safe to do something (typically go to low throttle) when the RX battery goes low .. then "release" it by taking the throttle stick to idle. This is useful on a prop plane where F/S does not have to kill the engine, but not so useful on a turbine. But you can set some other channel to do something on low RX batt and set some other control than throttle to "release" it. I must admit, I have not used this feature with a turbine model .. maybe something to think about. Very useful for prop planes, though.

The idea is this: The way the radio "tells" the ECU that a failsafe condition has happened is to go to a throttle setting outside of the range that was taught. Unless you are using the two-input signal method, this is the only way the ECU can know there is a failsafe! Again, other than the RX throttle signal going away (dead batt, unplugged wire, etc) this is the only way the ECU knows that a failsafe has happened.

Specific behavior on receiving a failsafe is set up in the ECU, and each is a little different. Some let you react to a failsafe by going to a pre-set thrust, but after two seconds, they must shut down to be AMA legal. A lot of guys go to a low/intermediate thrust setting (e.g. 10-20%) and drop the landing gear so they know they have a failsafe .. and if control is back within two seconds, they are back to normal but at least know something happened.

To be Joe Nall-legal with a non-turbine, you only have to go to idle, not shutoff, so you can just set your TX throttle to the idle setting and push the F/S setting button there. For the turbine, you have to force the TX to output a signal outside the teaching range.

You will see threads where people have mysterious turbine shutdowns if they have some setup that takes the throttle setting outside the taught range .. above or below the range!. I believe this is common with JR setups when you don't do the second post-F/S rebinding.

Anyway, it is a little alarming if people are flying turbines without a correct F/S setup .. and I guess without ever testing it .. I sure hope not! I would suggest that it's well worth it to start up the turbine take it to 1/4 throttle or so, be ready with a blower just in case there is any issue getting a cooldown cycle initiated, and shut off the TX. The RX should go into failsafe. If the radio was left at default (hold, or go to IDLE), having never set up failsafe, the turbine will either hold its speed or go to idle, but would not shut down.

A correct F/S setup will shut it down and most ECUs will report Failsafe as the reason for shutdown. Then and only then are you good to go, and AMA legal (and common-sense compliant!)

Dave McQueeney

Mr DJ

Dave

Thank you, Sir...

Mr DJ

BaldEagel

Interesting, I had to reverse mine to get the fail safe in the ECU to work, due to the pulse width being set up for JR gear which is the reverse of Futaba.

Mike

Bob_B

My Feedback: (11)

Mike,
What turbine are you referring too?
Bob

BaldEagel

I have two JetCat's which both required the throttle to be reversed before I could get the fail safe to work correctly, this is using a 12FG Futaba Tx.

Mike

Bob_B

My Feedback: (11)

Hmmmm. I hear what you are saying. I helped my friend setup his Titan with a 12FGA.
I know that I have to reverse the Throttle for ESC's to respond correctly but I thought I read in the JetCat manual were it was not necessary as the ECU would learn the pulse. Reversing the direction is simple enough or there is the option to reverse the function in the Hardware menu too!

BaldEagel

As far as I know its something to do with single channel operation where the ECU is expecting to see the trim at one end of the throttle movement and not the other to allow a normal shut down, or indeed a fail safe at that end of the throttle responce.

Mike

sarahblack

cool

davidgeorge212

Are the futaba 12fg radios compatible with the 6ch Futaba 606fs receivers? If so how do you get it to work?

BaldEagel

The 12FG is compatible with the 606, but only with the TM14 Module in 7 channel mode, you change the mode in "Linkage Menu" under "Frequency" change from FASST Multi too FASST 7 channel.

Hope that helps.
Mike

davidgeorge212

Ok, I dont think I have the tm 14 module. I just have the one that came with 12channel transmitter

BaldEagel

Did your 12FG come with the 6014 Rx and does it operate all the 12 + 2 channels on it, if it does its the TM14.

Mike

davidgeorge212

Oh ok, I am away at college and I dont have the transmitter with me so I cant check it for sure but I know it came with that receiver.

GrayUK

That will be fine.

Paul

DougV

Hi Paul,

Have you seen this new Futaba S-Bus setup? http://www.rcmarket.org/s-bus-pg-32.html

Doug.

powerjets

My Feedback: (1)

Be very CAREFUL..., I dont think 606 works correctly with 12G.
Check Futaba website on compatability !!

DougV

The R606FS will work fine with any of the Futaba (air) radios, the issue was with the TM-7 and TM-8 modules only.

Doug.

GrayUK

That is true, no problem with the 12FG.

Paul

GrayUK

Interesting.

A bit much for me but i can see how it could be used on larger models.

Paul

ela

Hallo. Anyone knows if the range on the 12FG fasst decreases slightly as the voltage gets nearer the alarm limit? Got my first failsafe condition today in a CARF Hawk. Not to be repeated to often i hope. All went well.

BaldEagel

I have had the Tx battery alarm on my 12FG activate on a couple of occastions without any misshap or loss of control, I would look at the battery being low at the other end i.e. the servo rx battery.

Mike