I'm trying to find out what happens to cause a wide open throttle I understand batteries could be a cause but is it the batteries in the transmitter or reciever or either that can cause this wide open throttle ? and does it have to be already wide open then batteries die and it stays open or does something make it go wot ? ALso if your reciever is suppose to lock the breaks down if it loses signal will it be able to stop it during wot ?
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Trying to understand a runaway rig
- Thread starter bobbd
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J.LO's SAVAGE X
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- eudora kansas
if you have the 2.4 hpi system. you may not have the fail safe engaged, and also if there is any nick , cut, or frey in antenna, it will cause wide open run away. check antenna carefully, there are instructions, on youtube or your manual on how to set failsafe.
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I thought we went over this in your other thread, the 4 cell battery holder and alkaline batteries just do not have the capacity or voltage for more than a couple minutes of operation under the BEST of conditions..... you went a few tanks of fuel then did not change the batteries and the truck ran away and that is that, the truck needs a return spring and a 5 cell 6 volt hump receiver battery from the factory but that is neither here nor there, you learned a lesson and should take precautions in the future to do all you can to prevent another runaway possibly damaging someones property or god forbid hitting a small kid....
Read the manual for the radio and set the failsafe to help prevent this, but be aware it only works if the system loses signal and does NOTHING to prevent a runaway due to dead receiver batteries or a problem with a servo, I know the learning curve is STEEP, I was a new guy once also and back then we didn't have the internet or forums, we were on our own and had to make do with meager help from a hobby shop or if we were lucky meeting another nitro guy and him helping us learn some of the tricks.....
Read the manual for the radio and set the failsafe to help prevent this, but be aware it only works if the system loses signal and does NOTHING to prevent a runaway due to dead receiver batteries or a problem with a servo, I know the learning curve is STEEP, I was a new guy once also and back then we didn't have the internet or forums, we were on our own and had to make do with meager help from a hobby shop or if we were lucky meeting another nitro guy and him helping us learn some of the tricks.....
There's no need to berate him for trying to understand the situation. He is asking valid questions.
The receiver battery is what could potentially trigger the failsafe. Though, I believe that some transmitters have a similar setup. For it to be stuck WOT, the system would have needed to lose signal or sufficient voltage while in the WOT state. Basically it holds whatever state it was in before failing. The failsafe usually needs some form of programming to function, but the intent for a nitro rig is to engage the brakes when the failsafe activates. This ofcourse also has the side effect of negating the WOT because of how the carb linkages function.
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Some of the old school external fail safes would engage when the receiver voltage went too low as well. None of the built in receiver fail safes I've come across do that. They only engage when there is loss of signal.
Also, every time I had a run away, it was due to water in the servo. Oddly, every single one of them that died due to water always went WOT and stayed there. They would overpower the TRS, so it was useless for my few scenarios. I've stopped using non-waterproof servos for throttle/brake many years ago. Learned my lessen with that.
My guess is that your losing power when your on the gas and the servo just stays where it was.
One other side effect of those 4 cell holders is that they tend to not hold the cells very well, or they hold them too tight. Then when you jump or bang into stuff, the battery slides, which severs power, then the spring that is pushing on the battery isn't strong enough to overcome the grip of the plastic holder, so until you spin the cells by hand, they don't make a good connection again. Or, until you smack into something and the cells move due to the impact or vibration of the engine.
Regardless, using a 4 cell holder isn't a great idea. Just adds more failure points to getting power to the receiver.
Depending on the servo and TRS (throttle return spring), I've had some that weren't strong enough to move the servo fully when power was lost, but usually, they will at least close it some so it's not running WOT when it smacks into a tree.
Also, every time I had a run away, it was due to water in the servo. Oddly, every single one of them that died due to water always went WOT and stayed there. They would overpower the TRS, so it was useless for my few scenarios. I've stopped using non-waterproof servos for throttle/brake many years ago. Learned my lessen with that.
My guess is that your losing power when your on the gas and the servo just stays where it was.
One other side effect of those 4 cell holders is that they tend to not hold the cells very well, or they hold them too tight. Then when you jump or bang into stuff, the battery slides, which severs power, then the spring that is pushing on the battery isn't strong enough to overcome the grip of the plastic holder, so until you spin the cells by hand, they don't make a good connection again. Or, until you smack into something and the cells move due to the impact or vibration of the engine.
Regardless, using a 4 cell holder isn't a great idea. Just adds more failure points to getting power to the receiver.
Depending on the servo and TRS (throttle return spring), I've had some that weren't strong enough to move the servo fully when power was lost, but usually, they will at least close it some so it's not running WOT when it smacks into a tree.
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Forgot to mention, the sliding switches on rc's fail a lot due to the abuse they receive in the elements. So you could be losing power at the switch as well. I burned a lot of time in the past due to a bad switch. Replacing battery packs, resoldering them, replacing receivers, servos... all to end up with a switch that is dodgy. It's good to have a couple spare switches on hand.
That's one of the nice things with running electric. Esc switch working weird? Cut it off and solder the wires together. You get power when you plug the packs in.
That's one of the nice things with running electric. Esc switch working weird? Cut it off and solder the wires together. You get power when you plug the packs in.
