NEW POLL - do you use a throttle kill switch?

[David Ashby - Moderator]

Not that I'm disputing the use and safety bias, but I just wondered. 

At the RCM&E fly-in, someone on the flight line asked whether I had a throttle kill switch programmed for my electric-powered model. I had to admit that I didn't and for a moment got the impression I'd be turned away. 

It's something I rarely employ as I'm comfortable with my own safety regime but I wondered if some clubs insist on the measure. I can see the obvious benefit with quadcopters etc. but do you have the feature programmed for every fixed wing (electric) model? 

 

 

Edited By David Ashby - Moderator on 26/10/2019 09:33:07

[sgwlm]

one of the first things i set up, throttle isolate/disable/kill switch, also add some red heatshrink over it so it is easily identified,

it is also something i make sure that anyone i am teaching has set up.

All my planes have throttle arm/disarm safety switch, i never take anything for granted, even as careful as i think i am, 

safety is for everyone and not just the pilot, 

Edited By sgwlm on 26/10/2019 09:37:32

[Keith Berriman]

Definitely when bending down to pick up the model to remove battery and 90% chance catching throttle stick better safe than sorry

[leccyflyer]

I do on some models, but not on all models. It's a useful feature to have but, as you say, your own safety regime is what really matters and to use it every time. Where the throttle kill switch is good is in preventing an inadvertent activation of the throttle stick whilst carrying the model, or bending down to pick it up.

When we put all these labels in our models would be an excellent time to add that feature to the programming for that model. I always used to have an ID label in each model, which has been beneficial on at least one occasion, but have lapsed in recent years. I'm planning to relabel the whole fleet and will add that throttle cut function at the same time.

[Chris Bott - Moderator]

Always. Every model. For the simple reasoning of why wouldn't you? and to keep all my models the same.

Mine are a "sticky throttle cut" which means that when the switch is moved to "enable", nothing happens until/unless throttle stick is fully down. This way, an inadvertent knock of the switch can't accidentally start the motor.

Also, when the motor is enabled there's a clear announcement of the fact.

I still don't rely on it for complete safety. Only a disconnected battery will do for that.

[Jason-I]

I ALWAYS use a kill switch, however, my view is that a kill switch should be made an industry standard. Even basic cheap 4ch radios should have a kill switch fitted. This would only cost pennies extra on the radio.

[Martin Harris - Moderator]

I can only think of a single reason why you wouldn't use one - and in my case I've negated the effect by fitting a locking switch - which is the possibility of disabling the throttle in flight accidentally.

Otherwise it's just such a simple way to prevent needless accidents. It looks like you are wearing a neck strap in your avatar, David - if you use one I would urge you to program a throttle kill switch on your transmitter for every model however thorough your safety regime. I have witnessed too many incidents where neck straps have caught throttles...

[Trevor]

Yep, every time. The Tx won’t fire up unless the throttle is locked off. And by using it on every model it becomes part of the routine to lock the throttle off after flight.

[Capt Kremen]

Strange some folk don't as a matter of course employ a 'Throttle Cut' ?????

It is a feature of most, (if not all), modern radio program set-up menus.

Two seconds to set-up, could save two digits or more from the accidental chop!

[Peter Miller]

My Early Spektrum DX7 does not seem to have one. (one of the first in the country)

My Hitec Aurora has but it took a long time to find and I use it.

[leccyflyer]

Indeed, there are many thousands of radios in use which don;t have the capability to have a throttle cut, so not really all that surprising that it's use isn't completely universal.

[Tim Kearsley]

Absolutely do, on every single model. I use OpenTx on a Taranis now, and have a switch set up such that it will only arm the motor if the switch is in one position AND the throttle stick is at idle. It's so simple to do and offers a decent level of protection that I'm not sure why you wouldn't do it. I also have the radio announce "Throttle armed" and "Throttle disarmed" appropriately. Additionally, at power up of the Tx, it warns if the throttle isn't at idle.

Having said that, it's important to remember that ESCs CAN be faulty and always be aware that once the battery is connected the motor COULD spin!

Tim.

Edit - Just realised after posting that Chris Bott had already very eloquently made all those points!

Edited By Tim Kearsley on 26/10/2019 11:19:39

[Tim Kearsley]

Just one additional point on this - a few years ago the Spektrum Tx I used didn't offer a dedicated throttle cut function, but it wasn't difficult to implement it via a switchable throttle-throttle mix. As always, there's more than one way to skin the cat.

Tim.

[Peter Christy]

All of my helicopters have a "throttle hold" function, used whilst carrying the thing out to the flight-line as well as auto-rotations. In addition, I usually program the trainer switch as a throttle kill on the IC powered ones.

On electric models, I always program a "throttle inhibit" switch - one some bigger models, two in series - to prevent accidental knocking of the stick opening the throttle.

Just seems like common sense - especially on electrics!

--

Pete

[Capt Kremen]

My (early) Spektrum DX6i had a throttle cut 'button' on the top right of the Tx case. Not very good as it required depressing to activate but became active once released! This was very easily remedied by installing a 'Maplin', (remember that handy if expensive store!), two-way switch. Voila! Positive On/Off arming of the throttle.

My current Multiplex 'Cockpit' Tx has an ever so nice, if somewhat stern, lady announce 'Check the position of all controls' should I switch on with the throttle stick advanced above zero. There is also the facility to allocate the 'throttle cut' switch itself, to any switch on the Tx.

Safety Is No Accident!

[Bob Cotsford]

I have a standard motor disable set up on a rotary switch on all my models, with verbal warnings when it's disabled or enabled. It's just about impossible to accidentally enable the throttle using a rotary switch.

[Wingman]

Can't see the point in a throttle cut (or inhibit switch) as it's just something else to get wrong - which way is off and on? - but I suppose if it gives you a warm fuzzy feeling then that is OK.

If you just place the throttle stick at half way when connecting the battery then the esc won't activate and the motor won't start until you return the stick to zero and then move it up again - note: that is two movements to activate - difficult to do accidentally!. Works on any transmitter old or new, needs no programming and is highly visible.

[Danny Fenton]

Always use one. Same sticky throttle mix as Chris, so two layers. Even on my indoor models. Somebody saw my X7 tx when it was just out, picked it up to feel the sticks, my indoor scale entry for the nats, shot of the table, ending up head first on the floor.

Why wouldn't you?

[john stones 1 - Moderator]

Yes.

[Brian Spearing]

I use a 3-position switch. Up - motor stopped, Mid - throttle range is from off to fast tickover, Down - full range. Obviously the mid position is for i/c only. The reduced throttle range is handy while carrying an I/c model to the takeoff point.

[John Bisset]

Ah - I said no, since I don't have that on the model. I do have a kill switch on the transmitter, with highlighting and position reminder so really my answer should have been yes. Tsk.

[Gary Manuel]

No - but there's a reason why I don't.

I like to have the same switch allocated for the same function on all my models. I use a sprung 2 position switch on my I/C models which is used to kill the engine when pressed. It either works by just fully closing the throttle or by operating a kill switch when one is fitted to the model. The sprung part of it reduces the risk of me accidentally killing the engine whilst in flight (plus it only works in the flight mode I use for take off's and landing). The same sprung part of it makes it useless as a kill switch for electric though.

I'm planning on switching to a Horus Tx soon, so maybe I'll rethink this as a Horus doesn't have any sprung switches (I don't think), but is does have the flexibility to allow a sticky throttle switch to be programmed.

[PeterF]

I use a Hitec Aurora 9 and the touch screen on it has a throttle lock function so when moving a plane with batteries connected onto or off the runway, I always activate this and it locks the throttle off. It needs a press and hold for a second or two to activate the throttle stick, so it is in my view better than a physical switch as the throttle can not readily be activated should you stumble or fall over.

[Brian Hammond]

My DX6 has a nice young lady to warn me about throttle setting and cut.

[Martin Harris - Moderator]

Posted by leccyflyer on 26/10/2019 11:09:57:

Indeed, there are many thousands of radios in use which don;t have the capability to have a throttle cut, so not really all that surprising that it's use isn't completely universal.

As has been mentioned, very few programmable transmitters are incapable of a throttle to throttle mix controlled by a switch - although a fairly modern Futaba [TF8J iirc...has a horrible touch sensitive rotary programming control?] owned by a clubmate had me scratching my head for quite a while. Anyone developing a similar bald patch is welcome to PM me for the solution...

I would no more think of not implementing a throttle kill/lock [or whatever you wish to call it] on any transmitter that was capable of supporting it than not set a failsafe. If it's possible I'd recommend using or fitting a physically locking switch.

Edited By Martin Harris on 26/10/2019 14:16:21