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Failsafe and kill switch for noobs

messyhead

Well-known member
#1
There's a good thread at the link below about failsafe, and the need for them.

https://forum.flitetest.com/index.php?threads/neanderthals-and-failsafe.63075/

But up until I read that thread, I'd never heard of either failsafe settings or setting a kill switch. In the videos and things I'd read when I started in this hobby about a year ago, I never came across the subject. Now maybe that was me not watching or reading the right things, or that I wasn't in a club where someone would have brought it up (another reason to join a club), but either way I never had them set when I was flying. In hindsight I realise how unsafe this was, especially as I fly with my son.

So I wanted to start this thread so experienced flyers could share their failsafe and kill switch settings for the transmitters and setup that they use, and hopefully anyone else that is new to the hobby, or hasn't set them up yet, can learn about this subject and what to do.

Hopefully it can be made a sticky so it's easily found.
 

messyhead

Well-known member
#2
Tx: Flysky FS-i6X
RX: ia6B and ia10B

Failsafe:

I set it to cut the throttle to 0, and do a left turn with some elevator. The idea being that it would spiral down where it is instead of flying straight or nose diving. This hasn't been flight tested, to this could change in future. But I thought this would be a good start.

IMG_20200502_175732.jpg

Kill switch:

The Tx I use needs to have all switches in the off (up) position, and the throttle down before it will switch on. But if I were to use the Throttle hold set to 0% and assigned to a switch, then by default the kill switch would be off.

So instead I saw a useful tip to use the Idle mode instead, and set this to a switch. The switch needs to be On (down) in order for the throttle to work, which is the opposite of the default up position when the Tx is powered on.

IMG_20200502_154217.jpg

I then set the Normal Throttle curve to 0%

IMG_20200502_154235.jpg

And the Idle up Throttle curve to the default settings

IMG_20200502_154244.jpg
 
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Hai-Lee

Old and Bold RC PILOT
#3
I have many tips for the setting of failsafe and will start off with a general warning for those who are using DSM2/X radios.

1. Unlike the Menu driven failsafe of many other systems Spektrum uses the control stick and switch positions on the Tx itself at the time of binding as the failsafe settings.
2. The type of failsafe that you can set is totally due to the capabilities of the Rx that you are using and so you need to read and follow the instructions or manual that comes with your receiver.
3. There is no possible way of disabling failsafe though you MAY be able to choose between failsafe and Smart Safe.
4. The failsafe type selection is done by the way the bind plug is used.

It is recommended to check the failsafe operation before each flight as some combinations of transmitter and non-genuine Spektrum receiver can forget their failsafe settings or even corrupt them and assume high throttle setting somewhat randomly!

Have fun!
 

cranialrectosis

Well-Known Member
Mentor
#4
Please test failsafe after any major crash or after you alter the programming such as on a flight controller.

Please Please Please get VIDEO any time you are nuts enough to test failsafe or do a calibration with the props on. ;)
 

Hai-Lee

Old and Bold RC PILOT
#6
It is wise to restrain the model if doing the tests with a prop fitted, For this purpose I carry a dogs leash and a small tent peg, especially if helping others with unreliable failsafe settings.

I actually test my failsafe operation settings by powering the Rx up first and listening to the tones sequences it emits. The ESC will enter program mode if the failsafe setting is dangerous, (not for minimum throttle), and without the Tx signal the model will never start the motor. Refer to the operation of Smart Safe as explained by Spektrum.

Have fun!
 

messyhead

Well-known member
#7
Please test failsafe after any major crash or after you alter the programming such as on a flight controller.

Please Please Please get VIDEO any time you are nuts enough to test failsafe or do a calibration with the props on. ;)
I might 'retire' a model by testing failsafe, just to see how it handles with my settings. One of them is a bit beaten up and needing rebuilt anyway.
 

Hai-Lee

Old and Bold RC PILOT
#8
There are other things you can use failsafe for other than crashing your model to avoid a fly-away.
1. You can taxi the model out to the end of the runway while holding the range test button and thereby avoid the requirement to walk a distance from the model and verify that the transmitter is working properly.
2. You can use a "Bomb Drop" mechanism to drop a ballistic parachute and then watch the model float gently (?) to the ground.
3. You can change the operating mode of the flight stabiliser so that the plane flies itself gently and slowly to the ground, (minimum possible speed).
4. If using a flight controller you can activate the "return to home" feature rather than crashing the model.
5. You can have the model disconnect the receiver you are using and select a different receiver. This is great for testing the range of suspect or repaired radio equipment or even a straight line flight for maximum range testing or long distance attempt.
6. A lost model is a sad event but you can use failsafe to activate an alarm and a flashing beacon so that makes it easier to relocate the downed model.
7. If used on a 3 channel model with large dihedral or polyhedral the model can be set to circle so that you can walk towards it and thereby reduce the distance to the model and regain control for a safe landing.

What you use and why is entirely up to you but cutting the throttle is a must if you are to reduce the risk to others and avoid possible litigation.

Have fun!
 

Andrew

G'day Mate
#9
......
It is recommended to check the failsafe operation before each flight as some combinations of transmitter and non-genuine Spektrum receiver can forget their failsafe settings or even corrupt them and assume high throttle setting somewhat randomly!

Have fun!
What model of Tx and Rx have you seen this happen to (forget their failsafe settings or even corrupt them and assume high throttle setting somewhat randomly)???.

I've been using Spektrum for over 10 years now and I have never has this happen to me or see this happen to other people.

I've seen new members turn up with their model and the failsafe is at a random position because they have NO idea that a there is a failsafe feature.

There is a scenario when using glow/gas engines, sometimes when setting up the throttle servo you may have to reverse the channel so the throttle push rod is working in the right direction.
NOW this is where people get a false failsafe position setting, the failsafe doe's NOT follow the now reversed throttle setting, people that have had this happen swear black and blue they had the throttle at low when binding and then a few days later when doing the throttle servo linkage DID have to reverse the throttle channel for the right direction, you MUST always reset the failsafe after reversing the throttle channel !!!
I believe Spektrum should make this more clear in the instructions (won't make a difference if you don't read the manual)
 

Hai-Lee

Old and Bold RC PILOT
#10
What model of Tx and Rx have you seen this happen to (forget their failsafe settings or even corrupt them and assume high throttle setting somewhat randomly)???.

I've been using Spektrum for over 10 years now and I have never has this happen to me or see this happen to other people.

I've seen new members turn up with their model and the failsafe is at a random position because they have NO idea that a there is a failsafe feature.

There is a scenario when using glow/gas engines, sometimes when setting up the throttle servo you may have to reverse the channel so the throttle push rod is working in the right direction.
NOW this is where people get a false failsafe position setting, the failsafe doe's NOT follow the now reversed throttle setting, people that have had this happen swear black and blue they had the throttle at low when binding and then a few days later when doing the throttle servo linkage DID have to reverse the throttle channel for the right direction, you MUST always reset the failsafe after reversing the throttle channel !!!
I believe Spektrum should make this more clear in the instructions (won't make a difference if you don't read the manual)
Sadly the incorrectly set failsafe occurs at the local club mostly amongst those using Spektrum and a variety of Orange receivers. I do not think that the Tx or Rx are to blame but it is their lack of understanding which failsafe is supported and the procedure to set it up.

I raised the matter directly with Horizon Hobby support and got an answer that was not topical and actually against what the manual indicates. The answer I received was that if the receiver is powered up first you will/may need to rebind the receiver! The Spektrum manuals state clearly that powering up the receiver first is safe and that the receiver will work fine. Mind you if the transmitter GUI is stored in the same memory as the failsafe settings and it is possible to corrupt the memory in connecting the battery this might explain a lot.

I find that Spektrum radios are OK but the crazy myths and legends circulating about them are ridiculous and some even come from Horizon Hobby support staff themselves!

I hope that the support line person actually knows little about the radio operation and the engineers are contactable via a different means if at all.

Still trying!

have fun!
 

Hai-Lee

Old and Bold RC PILOT
#14
Sadly I have worked as an engineer for a communications manufacturer in the past and I was required to be partisan in my recommendations so I do not take recommendations from an engineer working for the product manufacturer!
I do however converse with engineers when I have a issue or wish to know a feature of an equipment as they normally have intimate knowledge of the chipset and firmware used.
With all the info I make my own decisions and recommendations!

Its just me!

have fun!
 

Andrew

G'day Mate
#15
Sadly I have worked as an engineer for a communications manufacturer in the past and I was required to be partisan in my recommendations so I do not take recommendations from an engineer working for the product manufacturer!
I do however converse with engineers when I have a issue or wish to know a feature of an equipment as they normally have intimate knowledge of the chipset and firmware used.
With all the info I make my own decisions and recommendations!

Its just me!

have fun!
I'm not sure what you mean about recommendations, just if you had questions, anything technical that you need a answer to like, firmware, failsafe settings, mixing, battery settings, telemetry, antana placements.
Andy Kunz is the software developer for Spektrum, if you need advice get it straight from the horses mouth, the person that wrote the code or he is sitting at work right next to the person who did.
 

Bricks

Well-known member
#16
With the Spektrum DX series transmitters if you reverse the throttle servo in the transmitter on a gasser or glow it tells you right on the screen the receiver needs to be rebound and will not let you go any farther. Rebinding resets failsafe to the right position throttle off.
 

Andrew

G'day Mate
#17
With the Spektrum DX series transmitters if you reverse the throttle servo in the transmitter on a gasser or glow it tells you right on the screen the receiver needs to be rebound and will not let you go any farther. Rebinding resets failsafe to the right position throttle off.
It's good to hear that they have changed that, my DSM2 Dx6i and Gen 1 Dx8 don't do that, the only warning it says is,

CAUTION
Confirm
Throttle Reverse
Are you sure?
NO YES

That's the only caution I get when throttle reversing, it's been many many years since did a firmware update on the Dx8, it's about time I do it.