why don't they fix this?

[xfusion]

This is a question that has been on my mind for a while now. When you turn off the transmitter while the reciever is still on, why does it automatically put throttle to full? I'm sure that most of us have either started our trucks with the controller off, or accidentally turned off the controller with the reciever still on. Why don't they make the reciever turn off power when no signal is detected, hell it knows when the controller is off, can't it just idle or set everything to Home instead?

[RC10tee3]

my Mtroniks esc shuts off everything when theres no radio signal

[fz1]

Place a fail safe on the car. You should be running one anyway just to protect your car and others from a runaway. it would move your servo to brake if your signal was lost.
Cheap insurance and it takes care of your problem.

[B4 Stealth]

yeah all the ESC's have built in failsafes.

[Neon_Dave]

^^^ I'll have to disagree. Not all ESC's have a built in failsafe - or at least not quite a failsafe - what some of them have is that they kill the throttle, but also lock the steering servo either left/right - causing the car to roll into something from whatever speed you lost signal at. Better than a runaway, but still dangerous.

-Dave

[z-man280]

guys, i think he is referring to nitro's....

I agree, there should be a "FULL KILL" when no signal is received, not just a failsafe to return things, but a full shut down,...but it would require choking fuel or cooling the glowplug instantly. Even with failsafes, nothing beats a good return spring..

[xfusion]

Ye sorry I was referring to Nitros primarily. A full kill would be awesome, but you don't have to shut the engine off, just return the throttle position to idle, and set the steering to Home or 0*. This would not help you in case your battery dies, but this could be solved by a simple onboard temporary battery that stores just about 5 seconds of charge. So, if the battery dies, it'll activate, return everything to Idle and steering to center and shuts off.

[InspGadgt]

Your reciever picks up stray signals on the same or nearby frequencies. The only way to have it shut down is to use a coded signal that the reciever identifies as the signal directed toward it. You will find this in PCM and DSM radio systems in their built in fail safes as they do use a coded signal. So other then going to PCM or DSM there is no way to fix this within the radio.

As for ESCs...I haven't heard of any that have a built in failsafe...typically that is in the reciever or an external failsafe.

[JDT]

Just about two weeks ago a local basher buddy of mine was bragging up his m11 with spektrum as being foolproof and within 30 minutes it had a run away and ended up in a hog confinement pond, he spent 30 minutes at the car wash and that poor savage still smells like something died in it, needless to say he lost the receiver and receiver pack and had to send his newly modded engine back for rebuild(another $170), last weekend he showed up with a return spring. 99 cents sure could have saved him some time and money, let alone his truck has to live in the garage now as it stinks to bad to take inside, he is convinced the foams got nasty so he will actually need new tires also to try and get rid of the stink. Alot of guys have big money in there trucks it only makes sense to protect it with a failsafe or a return spring or even both IMO. Of course we can now call his truck the SS as in sh__ty savage lol.

[terrible-t]

I'm no expert on this. But, agree on Gadgets saying, there are no Failsafes on any RX. When you turn off your TX, its turning off a circuit that involves the RX. Shutting down the RX. Your RX probably has a capacitor that discharge internally. So its discharges through your throttle servo. A phenominum in electronics. Electricity searches for the least resistance, through the servo. It probably change if you turn off the RX first... No expert but my opinion....

[Ball Racing]

If you get a erratic signal, a throttle return spring does not bring it to idle,
you know that same servo gives it the GAS,
Run a spektrum system and you have that fail safe you want.
You can start your car in the pits with the transmitter off, if you want.
Have some people experienced a glitch with spektrum? yes the other 90% haven't.
When a wack signal intefernce tells servo's to move, springs are just there for the ride.(but i do run one on all my vehicles)

[Demon-TC3]

Ok first of all yes SOME esc have a failsafe encorporated (Mainly the Mtroniks Vipers do).
But the reason you will find that your servo goes to full throttle when you turn off the TX is because of the transmittion is ended, even at neutral your transmittor is telling your car to be in neutral, its still giving a signal though. so as soon as you turn off the TX one of a few things can happen:
Either the neutral signal is cut and you get a random signal as the very last transmition, this is not a complete signal so you get a random input, in your case full throttle...
OR that your receiver looks for absolutely any signal it can find (which is why at the racetrack youll find you get allot more interfiarance if your TX is off)
but its not always a radio signal, an electric motor spinning creates allot of interfiarance and ANY current carrying wire creates interfiarance (negligable ammounts though)...also i think that perhaps a running engine would also? (not too sure)

Now as far as i remember thats why it happens, i may be wrong (an old plane buddy told me about the first thing) but it may explain a thing or two...

[cenracer1]

terrible-t... You are right in some part but I just picked up a hpi baja 5b and there is a built in failsafe in the rx... yes that right the rx... I tested it several times yesterday and it works well.. just to confirm, I opened the radio box and the brake adjustment screw is on the rx... quite cool.. I didn't have to buy a sep one... But on the other hand... for about $1000 dollars it should be there... Just to be safe, I replaced the stock rx pack with ib4200's from promatch racing and put a volt meter and will put a return spring on it... 22 pounds and 40 mph is a lethal comb... 99 cents for a spring to save 1000 no brainer

[InspGadgt]

No system is ever fool proof...but there are things you can do to reduce the chances of problems. First off a fail safe and a throttle return spring protect your car from 2 completely different possible failures and as such neither one alone is sufficient. A fail safe will protect you from radio interferrence and loss of signal, but it will not protect you from a loss of power to the reciever. Conversely a throttle return spring will protect you from a loss of power to the reciever, but it will not protect you from a radio interferrence or loss of signal. So really you need both. However a note on the throttle return spring...it has to be strong enough to pull back the servo when there is no power applied...so standard servos will take a much stronger spring then a coreless or coreless digital servo for it to work. This will cause extra strain on the servo and eventually cause servo failure. A coreless or digal servo typically requires very little effort to turn the servo horn without power so a light spring can be used to cause less wear and tear on the servo. I highly reccomend that anyone running nitro vehicles at least spend the money on a good coreless or digital servo for the throttle servo. It may cost you more initially...but in the long run it will save you money.