Throttle Cut?

[ICM]

I have an Apprentice S 15e and set it up on my Spektrum DX9 with SAFE modes on the 3 position B switch. I didn't bother with Dual Rates or Expo as I was advised it wasn't necessary on the Apprentice. I set up Throttle Cut on the 2 position H switch and the default is -130. Is this correct.? There is nothing in the manual about setting up Throttle Cut.

[xviper]

It is a safety feature that everyone needs to learn to set for any new model. It's covered in the manual for the transmitter. It's rarely covered in any manual for any given plane. Throttle cut on most Spektrum Tx that allow that feature, once selected and activated will always default to -130. This is the guarantee that whether you fly electric or liquid fuel, throwing that switch will ensure the motor stops. Don't mess with it in case you think it should read -100. Most servo travel is defaulted to -100 to +100, with the exception of flaps where it may require travel adjust or sub-trim to level them out. Also, some people will elect to adjust end point for "gear" or max throttle to make sure the retracts will see a defined end point or to make sure that max throttle is indeed achieved. On the most part, it's not wise to mess with those either.
In order for it to all work as it should, throttle trim on the transmitter should generally be lowered to the bottom, then throttle calibration be done. (This does not apply if you are dealing with a "fuel plane", since those need to "idle". Throttle cut will lower the throttle to below idle to shut the engine off.) Now the ESC knows where min. throttle and max throttle should be. Throttle cut ensures that you have less than "min." throttle for safety.
Additionally, don't confuse what it says in the "monitor" as compared to what it might say in (as an example) the flap system page, which is in terms of %. Same goes for rates and expo. These are also in different types of units.

[AirHead]

Throttle Cut Is A Must! A few times in past years, I had planes go "ape" on me. Luckily, there were no injuries. There could have been! When you think that a powerful brushless spinning a glass nylon prop, could easily slice your hands off, I decided to use this feature and now it's automatic! When I bring a plane in, I automatically shut out the throttle. I don't know why that isn't emphasized enough....

[boomer108]

I agree, I practice the same thing all the time every time.

[rifleman_btx]

Yes totally agree, a very valuable safety feature that everyone should use, one accidental slip is all it takes and you will wish you had it.

[fhhuber]

Just get into certain habits. (make a checklist if you need it)

All switches assigned the same way for all airplanes. If SW-A is gear, its always gear. If up/away from you is gear down, its always gear down.

Before turning on the TX, put the throttle down and put all the switches in the same position.

And now you don't need a throttle cut switch.

If you become dependent on a throttle cut switch, but don't set the habit of setting switches, then you might as well not have the switch... because you won't have the habit of pre-setting it to cut.
If you are in the habit of setting the stick and switches, the throttle will be in the right place.

That switch is only as good as your habit for setting it...
If you tend to randomly bump stuff on the TX, then the switch isn't going to help either because it will be in the list of stuff you randomly bump.

For me, its all switches up/away, throttle down, then power switch on. BEFORE putting the battery in the model.

[AirHead]

Even before I turn on the Radio, I check for throttle stick down and I check all switches; but that Throttle Cut switch stays on until I'm ready for action. If the radio slips; someone bumps it or some curious person decides to throttle up!....There will be blood! Just don't want to see it....

[rifleman_btx]

As I said first time you screw the pooch, you will have a mess you dont want

[OV10]

That big stick on the left side of a mode-2 Tx is the most common to inadvertently get "bumped" which begins the blood letting :Scared:
A throttle cut switch is truly a safety measure against the unprotected "bump"
The concern of bumping the Throttle Cut switch as mention by fhhuber is a true concern but easily remedied with any Tx that has a Rotary Knob.
I changed the Throttle Cut over to the rotary last year after I inadvertently fat fingered the TC toggle switch during take off.
There is no accidental turn on/off anymore. Requires a concerted effort to rotate that knob 270 deg to engage/disengage the throttle cut.
Almost a true fail safe throttle cut switch.
Wanna keep you fingers or your birds.........seriously consider using the rotary knob as your throttle cut. ;)

[rifleman_btx]

I might do that too, very cool idea!

[Grossman56]

I agree, a throttle cut is a must! Once on the ground and taxied off the runway, the last thing I do is hit the throttle cut and touch the throttle forward, just to make sure its actually engaged. Then I'll get in there and unplug the battery after placing the radio on the ground beside the airplane. With most of my planes, the battery can be plugged or unplugged while working behind the airplane. Ones like the Tigercat that I feel I have to work in front of the props, the radio is behind the plane and the throttle cut and throttle position are double checked before energizing the airplane. That way, I can see anyone approaching the radio and make sure they see it.
Our last fly in, one fellow had to be taken over to Emergency with a hacked up leg, all because he didn't ensure that the throttle cut was engaged. Not nice!!

Grossman56

[AirHead]

I haven't used the rotary switch on the DX9 yet. It does seem like an even safer idea because it's not a toggle and that's what this is all about...toggle switches being switched accidentally. I use the big switch on the upper right side. It beeps loud when you turn it on in the up position, so you know the throttle is locked. Rotary is a good idea though. Whatever switch you use for throttle cut, apply it to ALL the stored models!

[xviper]

Using the rotary for throttle cut may not be such a good idea. Safer? Maybe (but I highly doubt it), but NOT faster. Sure, you can easily brush up against the big switch on the top right of the TX, but remember, it's already a "failsafe" (or redundancy) for when you accidentally brush up against the throttle stick (but then, you should be able to hear it click or feel it). When you find yourself in a situation where you need to shut that throttle down in a hurry, you need that failsafe to be fast. It's there to prevent a moment of bad luck. No matter how much more you want to do, you will never safeguard against really, really bad luck or utter stupidity. It's sort of like having a key AND a kill switch on a motorcycle. Do you really want more? Do you really need more? For all the "Murphy's" out there, it will never be enough.
Also remember: ………………… With throttle stick at the bottom and all throttle trim set as low as it will go (what it should be for electric), the monitor indicates -128. When you throw the throttle cut, it goes to -130. On Spektrum (at least my DX8 G2), you cannot assign throttle cut to the rotary. But let's say you could, the rotary goes from +100 to -100. You'd have to make sure you reprogram the end points on the rotary or you could find yourself in a world of hurt or having a throttle cut that won't do what you hoped it would do. Nevertheless, I think Spektrum made it NOT possible to use the rotary for TC for a reason. Throttle Cut needs to be a switch.

[OV10]

Using the rotary for throttle cut may not be such a good idea. Safer? Maybe (but I highly doubt it), but NOT faster. Sure, you can easily brush up against the big switch on the top right of the TX, but remember, it's already a "failsafe" (or redundancy) for when you accidentally brush up against the throttle stick (but then, you should be able to hear it click or feel it). When you find yourself in a situation where you need to shut that throttle down in a hurry, you need that failsafe to be fast. It's there to prevent a moment of bad luck. No matter how much more you want to do, you will never safeguard against really, really bad luck or utter stupidity. It's sort of like having a key AND a kill switch on a motorcycle. Do you really want more? Do you really need more? For all the "Murphy's" out there, it will never be enough.
Also remember: ………………… With throttle stick at the bottom and all throttle trim set as low as it will go (what it should be for electric), the monitor indicates -128. When you throw the throttle cut, it goes to -130. On Spektrum (at least my DX8 G2), you cannot assign throttle cut to the rotary. But let's say you could, the rotary goes from +100 to -100. You'd have to make sure you reprogram the end points on the rotary or you could find yourself in a world of hurt or having a throttle cut that won't do what you hoped it would do. Nevertheless, I think Spektrum made it NOT possible to use the rotary for TC for a reason. Throttle Cut needs to be a switch.

It IS possible XV, have it in play for better than a year on the DX9.
For me the rotary TC switch is not about speed to engage but about taking away the more highly susceptible ability to inadvertently toggle a 2-pole lever which is just as easy as inadvertently nudging the throttle stick.
It's the BEST insurance I believe to avoiding an accident.(at least for me);)

[xviper]

Well, I can't do it on my DX8 G2. I guess if it works for you, that's good. For me, I don't see it for the reasons I've already touched upon.

[TiredIronGRB]

Just get into certain habits. (make a checklist if you need it)

All switches assigned the same way for all airplanes. If SW-A is gear, its always gear. If up/away from you is gear down, its always gear down.

Before turning on the TX, put the throttle down and put all the switches in the same position.

And now you don't need a throttle cut switch.

If you become dependent on a throttle cut switch, but don't set the habit of setting switches, then you might as well not have the switch... because you won't have the habit of pre-setting it to cut.
If you are in the habit of setting the stick and switches, the throttle will be in the right place.

That switch is only as good as your habit for setting it...
If you tend to randomly bump stuff on the TX, then the switch isn't going to help either because it will be in the list of stuff you randomly bump.

For me, its all switches up/away, throttle down, then power switch on. BEFORE putting the battery in the model.

This is the system I use as well, to me a throttle cut is a false sense of security, the only step I would add is I connect the battery when I'm ready to taxi and never leave a hot radio/plane unattended. No matter what system you use the main thing id to not get complacent.

[BRGT350]

I have started to add the throttle cut to my planes, last night actually, and mostly for the hand launched birds that I carry out to the flight line and toss in the air. On the larger ones that I can install the battery and taxi out for take-off, it isn't really needed. The battery is only plugged in when it is ready to taxi and then I pull the battery when I taxi off the runway before carrying it back. I have the throttle cut switch right above the throttle (switch C I think) that way I can flip the switch using my left hand while the plane is being held in my right.

[boomer108]

Well from reading everyone's different methods, I would say whatever works for you and keeps you safe is what its all about.

[ICM]

As the OP, my initial question was whether the default throttle cut value of -130 on my DX9 was correct for my Apprentice. I got an email answer from Horizon Tech that the default value was correct for the Apprentice and any other SAFE or SAFE Select plane. I seems which switch to use and even if throttle cut is really needed is a matter of opinion.

[rifleman_btx]

Lol yes indeedLOL