XenX

hey guys.. just wondering about a fail safe for my car.. what i wanna know is, what do they protect against?
my controller has a batt level indicator that turns red if they are getting low.. iv let it go to red b4 and it still functions the car from a fair distance so its a good judge as when to change the batteries.. as far as i am aware they only really protect against the car goin out of range right?
only couple of times my car has "ran away" has once been due to water getting in the receiver and the other time cause of a bit of grit off the road getting caught and jamming the accelerator on.. obviously there would be no protection against this sort of thing.. but as the range on these modern day controllers is so far anyway.. and the batteries in my controller arent gonna just suddenly die without me being warned.. was just wondering.. whats the point?

P.S. I am gonna get one just to make me feel more comfortable.. just interested to know the advantages.. after all its basically my bank balance on wheels goin at 50+mph down the road hehe

P.S.2 incase ur wondering i have now waterproofed(pretty much) my receiver..hehe not gonna let that little mistake happen again

Nitroaddict

a failsafe works if the batteries get low or you get frequency interference. they do not work of the batteries get disconnected from the car or the batteries die completely. they enable the servos to move to a preset position if they above mentioned occurs. they are good to use, but always use a throttle return spring too.

XenX

ahh see now throttle return spring sounds like a better device... can you explain.. hows it fitted wheres it go and whats it do? although the latter is pretty much obvious

FHHuber

Failsafes work on the basis of... set controls to a predetermined configuration if the reciever no longer is getting a signal from the transmitter (or the signal is garbled from interference)

They can NOT protect from low RX battery power. If the RX doesn't have the power to move the servos in response to the TX... it doesn't have the power to move em in response to the failsafe setting.

for a R/C car... all you need is failsafe on throttle to stop the car.

For an R/C aircraft failsafes can greatly minimize the impact when the plane hits. 99% probablility: If you meet the requirement for the failsafe to kick in... you are not going to be landing the arplane under control of the transmitter.

*** you seem to have posted while I was posting ***

A spring return won't work unless it can overpower the servo's idle position-hold power. It MAY work for a dead RX battery or other loss of power to the servo (especially digital servos which have virtually no resistance to movement on loss of power) it will be a HUGE drain if it has to overcome the servo with power applied. (and then you would have a hard time moving the throttle)

XenX

surely if ya get interference though the interference would be on the same channel as the transmitter/receiver are using so how does it determin whats interference?
it looks for twitches or something?
anyway i guess what im asking in general is are they reliable? can i count on it that, if my car goes pelting out of range or if some gimp is using i dunno a toy CB or sommet on a close channel, it will stop the car