Futaba FSU2 failsafe issues.

[Terry Keeley]

I've always used these and the older FSU1 units between the receiver and throttle servo on my boats. They work properly with 603FS receivers but for some reason they don't work with a 617FS, I turn the transmitter off and nothing happens. I tried a couple different units, none work.

Any ideas?

 

[longballlumber]

Terry if your still using guts from the original Fasst Module (C1) I don't think the 617 is compatible. Only the 603FS and 603FF are compatible.

https://futabausa.com/product-support/receiver-feature-charts/

 

[Daniel's Racing]

He is trying to get a stand alone failsafe that goes between receiver and servo to work.

I am guessing he has the 617 receiver working otherwise just won't work with failsafe in throttle servo wire.

I don't know why just explaining what he is trying to do. If 617 is working otherwise why can't standalone failsafe operate throttle servo.

Why even use 617's when there have been so many of the R603FF and R603FS. If it works with them just use them. Seen hundreds of the R603's being sold cheap in last year.

Remember the past 20 years we tried to get you to use LiFe batteries. Now you use them and love them. Radio is no different. We should start now on the transmitter and you will find out how nice new real transmitters work WITH digital servos and failsafes you set once and they work seamlessly on all channels.

You will be all set by 2041.

Yea yea your NiCd/NiMh batteries were good too the other day. Turn the page. Lol.

 

[Grimracer]

what in the heck does that asterisk mean in the table on the 617.. hum.. I have not noticed that before.. it is curious how you are able to use a 617.. I suspect it has to do with conversion you have on that system.

Did you mean the 614?

 

[Terry Keeley]

I went back through the Futaba transmitters and found the last generation to use what I call "real" trim pots (not the switches) and a knob for mixture was the 7UAP-UAF and the "super series".

Sooo, I grabbed one on Fleebay with a FASST TM7 module and 617FS receiver, was easy to change the sticks to Mode 1 (throttle on the right). It's rock solid and although I don't care for all the "bling" I'm getting used to it.

Problem is the FSU2 failsafe doesn't work. There is a failsafe built into the transmitter module but as I understand it you have to arm it every time you turn it on, also only works on CH3 which is not throttle for me any more. I see there's a "stick mode" for some transmitters but I don't think it applies to this one.

Why wouldn't the FSU work?

 

[Terry Keeley]

Futaba's reply:

These units are long discontinued and i have no information in them any longer.
Tony

 

[Grimracer]

I am not sure even Hobbicos time with Futaba was during this radios time. Gary Preusse has one of these I think.. he might be able to offer up a few notes.

Grim

 

[Grimracer]

https://www.manualslib.com/manual/378336/Futaba-Fp-7uaf.html#manual

 

[P THOMAS]

I used the Dynamite Micro Fail-Safe with my 3 pm fasst radios. I have a couple if you like to try them.

 

[SayMikey]

Terry if Mendota ever races again you need to come and bring that radio. You would win oldest working radio,yes there are a few guys in line for that trophy

 

[Terry Keeley]

That's similar to the Futaba unit I'm trying to use Phil, thanks. Still can't quite figure out why It works fine on the 603FS but not the 617FS.

Thanks Grimdude, I got the manual, no mention of a "stick mode" tho to switch the channels to Mode 1. Saw some posts to hold both Mode Select buttons down and turn it on but that didn't work.

Hey Mikey, even better:

I'll mess around with it some more and report back...

 

[Daniel's Racing]

Terry,
Is the servo free to move when you shut down the power to the transmitter.

Seems like the only time those stand alone fail safes would not work is if the receiver is still sending a valid signal to the servo.

Like if you used it on a channel that had fail safe built in the radio.

There must be some signal leaving the receiver keeping it from sensing loss of signal from transmitter.

I realize now you were not using R603's and the 617 from same transmitter. Didn't think they were same modulation type and cross compatible. Check it with a voltmeter and see if signal has output.

 

[Terry Keeley]

More from Futaba and my reply (seems I got someone now that actually gives a $hit):

Terry,
The 617FS receiver is a air protocol. It has a built in Fail-safe on channel 3. The 603FS is ground FASST C1 protocol. If you meant the 614FS it is ground FASST C2 protocol. The manual mentions not using the FSU2 with HRS systems.

https://futabausa.com/wp-content/uploads/2018/09/R617FS.pdf

Receiver Comparison Charts - FutabaUSA

http://manuals.hobbico.com/fut/fsu2-manual.pdf



Thanks again for the updated information. I'm using the 617FS with an old 7UAF transmitter and TM-7 module, the transmitter is in PPM mode therefore is shouldn't be an HRS issue should it?

I found the FS on channel 3 works, the problem is I converted the sticks to Mode 1 (throttle on RHS) and that is channel 2. Do you know if there is a "stick mode" on the 7UAF (not Super series) to change the channels to Mode 1?

I still can't get my head around why the FSU2 works fine with my 603FS receivers and TM-3 module and not the 617FS with TM-7...

 

[Daniel's Racing]

There has to be some Pulse Width Modulated voltage on the signal wire coming out of the receiver even after it looses signal from the transmitter.

Is the servo free when you kill the transmitter ?

 

[Terry Keeley]

Terry,
Is the servo free to move when you shut down the power to the transmitter.

Seems like the only time those stand alone fail safes would not work is if the receiver is still sending a valid signal to the servo.

Like if you used it on a channel that had fail safe build in the radio.

There must be some signal leaving the receiver keeping it from sensing loss of signal from transmitter.

I realize now you were not using R603's and the 617 from same transmitter. Didn't think they were same modulation type and cross compatible. Check it with a voltmeter and see if signal has output.

The servos are held in their neutral positions when I turn off the Tx, that might be a function of the "hold" setting tho.

I just confirmed the FS function works without having to set it each time you turn on the tx, woohoo. I think now all I need to do its switch the wires on the pots from CH 2 to 3 in the transmitter.

 

[Daniel's Racing]

The servos are held in their neutral positions when I turn off the Tx, that might be a function of the "hold" setting tho.

I just confirmed the FS function works without having to set it each time you turn on the tx, woohoo. I think now all I need to do its switch the wires on the pots from CH 2 to 3 in the transmitter.

Well there is your answer. If servo is locked it is receiving a signal.

The same signal that is keeping the stand alone inline failsafe from sensing loss of transmitter signal because it is still sending valid signal to hold servo.

When the receiver is capable of creating a servo signal on it's own without reception from the transmitter it can't work.

Servo is receiving a valid signal from receiver so failsafe doesn't know where it is coming from.

Swapping to a channel that doesn't do that is the answer as you know now. Hopefully swapping transmitter pot wires goes easily. If wires reach move/swap the pots themselves maybe if they are identical.

 

[Terry Keeley]

I think it's the "hold" function that's blocking the FSU from working, I can't figure out how to turn it off unfortunately.

Pg 10: http://manuals.hobbico.com/fut/7uaf-7uap-manual.pdf

 

[Daniel's Racing]

I think it's the "hold" function that's blocking the FSU from working, I can't figure out how to turn it off unfortunately.

Pg 10: http://manuals.hobbico.com/fut/7uaf-7uap-manual.pdf

Do you have the hold and F/S option for each channel like shown. Maybe hold will be eliminated by setting it to F/S since it doesn't work in PPM or does that not even show unless you are in PCM mode ? There should be some way there to stop the hold and not have that ON. I didn't definitely figure how from those instructions but you would think it would be possible.

You say it isn't doing it on all channels. That may be telling you since every channel is set the same way you probably can in fact turn it off or all the channels would be doing it the same.

Play in those settings and I believe you may figure out how to shut it down for any channel.

 

[Tom Foley]

Man you would love the old 3 PK ! Way back when I went to the 3 PB which is 75 Mghz PCM 1024 and then to the 3 PK and had no problem adapting to the wheel radios and I'm old lol !

 

[Daniel's Racing]

Man you would love the old 3 PK ! Way back when I went to the 3 PB which is 75 Mghz PCM 1024 and then to the 3 PK and had no problem adapting to the wheel radios and I'm old lol !

Work on him Tom !!! LiFe batteries took close to 20 years to convert Terry into those. A radio may take a little longer.

Maybe we can put a stick gimbal in place of the wheel for him. He likes radio mods.