View Full Version : WARNING - No failsafe with the GT5

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12-08-2011, 04:51 AM

I thought I would just warn you all as there seems to be no mention of this previously and no answer to several posts I made on this subject..

There appears to be no failsafe built into the GT5 when using spektrum sats..

I noticed this whilst testing on my 450 and tonight just bench tested with a servo in the throttle channel.. I bound several times to make sure..

When I turn off my TX - the throttle simply stays where it is..

When this problem was discovered in the Align 3GX there was a huge uproar and they quickly brought out firmware to fix it.. However, no-one seems to care about it when mentioned in the GT5?

So unless I am wrong - YOU HAVE BEEN WARNED !!!

PS: Does anyone know how to contact the manufacturer to query about this issue?

12-08-2011, 05:14 AM
That's because the 3GX resets itself up for no reason and then that becomes an issue :YeaBaby:
Seriously, if this is verified this is indeed an issue... I run Futaba sbus and I set failsafe in the Tx but I have not tested the effectivity in real life:oops:
Hope they are aware of this as I think they are working on an update.

12-08-2011, 05:23 AM
I would imagine any external RX setup is ok as failsafe will be a function of the RX and not the GT5.. That's why it's just an issue for Satellite only users.. which may be a lot of users!

12-08-2011, 05:27 AM
True, most use Spektrum / JR so you can bet a lot will be running the unit on sats! Hope they fix it before we hear any horror story. I assume binding in the GT5 with throttle at minimum doesn't change a thing?

12-08-2011, 06:06 AM
Nope no luck as that's how I did my testing.

1) Bind with throttle low
2) power all on and raise throttle
3) power off TX - no change in throttle (should move to low position)


12-08-2011, 07:12 AM
That is no big deal, your better off running a AR7100r receiver with the GT5 anyway if your using Spektrum or JR DSM2.
The TotalG has no failsafe and I have not heard any horror story's about that! Your throttle servo could be the cause of your brown out, so what happens then?

12-08-2011, 07:51 AM
I don't get your reasonning, what have I missed?
AR7100R on a trex 450? Won't even fit!
How can it not be an issue? What if the TX shut off or stops transmitting or battery fails? Although these are unlikely event, the heli would be a powered uncontrollable chain saw!
I have seen what kind of damage a 450 can do to a human arm and a car top and it is not pretty AT ALL.
IMO we should do everything possible to prevent that and that's what failsafe does.

12-08-2011, 08:51 AM
Yep - my worry is using it in my 550 with 2 sats..

The last thing i want is to loose radio with throttle 80% or more! God knows what would happen...

One of the points of using sats is so you don't need the wiring clutter of an external rx..
What's the point if fail-safe doesn't work and you have to use an external rx anyway..

also - as Benj mentioned.. receiver + fbl gyro on a 450 is a wiring nightmare. FBL gyro + sat is bliss.. but not worth the risk if no FS !!!

@NitroAl - I see some of your arguement.. but having no FS is just tempting fate and taking more risks. Why not lower the risks immensley simply by adding a FS feature.. after all - the oled display shows loss of signal, so the detection code is already there... a few lines of extra code to set throttle to FS position is virtually nothing in coding effort.. so I don't understand why you wouldn't want it...

12-08-2011, 11:00 AM
It's definitely an issue but check if it holds last position which is the best option as usually it will reset, vbar changed this to hold last position if I remember correctly
To be safe I run 2 sats always so really you should only have an issue if you loose power completely in which case motor will cut anyway on electrics with bec. I agree that tt should respond with a satisfactory answer to this question however

12-08-2011, 11:24 AM
That is no big deal, your better off running a AR7100r receiver with the GT5 anyway if your using Spektrum or JR DSM2.
The TotalG has no failsafe and I have not heard any horror story's about that! Your throttle servo could be the cause of your brown out, so what happens then?

It's a pretty big deal hey. Also, no one flies the TotalG anyway so it's it doesn't really matter.

12-08-2011, 12:34 PM
So my TX would have to fail, how often does that happen?

12-08-2011, 07:58 PM
So my TX would have to fail, how often does that happen?

No - you just need a signal loss through interferance or failure...

How often do you win the lottery - but many still play.. and does happen..

As most of us know with helis - it's not IF it's WHEN...

Also, on a small model where only one sat is usally used, you only need a faulty sat connection to have the model launch unpredicably..

some things that could happen:

1) loose signal whilst in a trajectory to earth (most favourable) - heli crashes into the ground virtually full steam.. great :(

2) loose signal whilst in a nice even trajectory or fff.. model could travel as far as 500m into anything.. 500m is often much futher from the public than most fly.. even thou you thought you were far enough away, your model could end up crashing into a crowd or car on the highway..

3) loose signal generally that results in an uncontolled model flying into unrecoverable bushland, forrest, ocean, suburbia, etc...lost forever because of a simple lack of failsafe..

12-08-2011, 10:36 PM
Yes , i see ,. I thought of a way to do a tidy mounting of a VBAr on my 6HV , so i'm starting to tip to the other side now.
i notice the failsafe on the Vbar was not straight forward either , a few tricks there, but a least they had support. Wonder if there are similar tricks with this. With the VBar & 2 sats , DX6i , trick is to flip on the throttle hold while binding.

12-10-2011, 11:08 PM
Jockstrap... I tried GT5 on my 550 with 2 sats.. confirming that it would bind fine but no failsafe present. Also the feature that allows the satellite light to flash to indicate brown-out does not work. This is a pretty shoddy implementation of the JR/ Spektrum satellites and I've now moved this unit to a larger heli that will support full receivers. Hopefully Thunder Tiger are working on resolving this issue as it's both dangerous and disappointing.

12-11-2011, 07:46 AM
Thanks for the confirmation Cleggy.. However I didn't now about the brownout indicator issue.. :(

I hope they fix this soon - I'm sure it's a simple fix for them too.. :arggg:

12-19-2011, 11:35 AM
well just yesterday I had both my sats fail on my tdr and it went into hold, this was on vbar and heli went in so I guess there's a first for everything. Just before this happened I logged a 242 kmh flight, imagine if I had this happen with no hold function! We trust these systems till things go wrong! I'm seriously considering going back to fullsize rx, sats led were solid, luckily I had the vbar log file to tell the story

12-19-2011, 12:23 PM
bugger! maybe i'll wait for the ar7200bx.!

12-19-2011, 10:30 PM
I"M gonna do some tests it seems these systems don't know when a sat has failed but when it wants to switch between sats it can't , so apparently led can be solid but sat may not work , this is here say though as I have to check it out, will post my findings here.
Beast x is an option but I'm vbar fan so id rather change to futaba
Interesting as yesterday we wanted to bind ace on my friend machine and it would bind but not initialise till we traced it to a bad sat, so maybe ace is onto something here, the same sat did "work" on vbar before, to be on the safe side pull one sat at a time and see if system initialises

12-19-2011, 11:49 PM
After reading this thread,I decided to run a separate rx,better safe than sorry,no biggie,I was coming from a old vbar,so I still lost one component.

12-21-2011, 10:38 PM
I see with a little search there isn't a big problem with Vbar/sats, there IS a problem with wire fatigue/breakage where the cable exits the sat.

12-22-2011, 04:23 PM
problem is vbar will initialise with one bad sat whereas ace will seemingly not a huge plus in aces favour, I'd much rather have an early warning system than a failsafe,
I'm gonna run some tests on both units soon regarding these issues as right now there is some speculation but for now I'd rather fly my ace with sats than my vbars, theyre going futaba now

12-22-2011, 10:35 PM

From cleggies post, so more confusion? i'm waiting to place my money :roll:

So besides faulty sat wires and Tx failure ,what else could kill signal ? What causes 'interference'?
I see the GT5 availability is pushed off till Jan. now , if its delayed some more i'll get the new bX & solve my questions.

12-23-2011, 03:36 AM
I see the GT5 availability is pushed off till Jan. now , if its delayed some more i'll get the new bX & solve my questions.

hugh? Where are you trying to get one from - I have 2 of them already and have had one for nearly 2 months aready ????

My 2nd one I even purchased 2nd hand - lol


12-23-2011, 01:59 PM
Well did some more tests if you cut signal wire on sats both vbar and ace will still show solid led's so no good, the ace did however pick up a problem with a sat which vbar didnt, dunno what it was but it would not initialse whereas vbar did,
NEw b/x spektrum is probably the way to go. only sats is an absolute no go for me

12-23-2011, 02:45 PM
You guys are just paranoid. Just look after the leads and fly the snot outa that thing!