Electric fail safe?

[Indian_Joker]

I searched the forums real quick and couldn't find much on fail safes. I can't help but to think that the throttle return spring is cutting back on my acceleration. How do I install an electric fail safe so I can take the spring off and not have to worry about a run away? Or is there a better way that wont rob from my acceleration?

 

[beason]

you really need both for the best protection. a failsafe only helps when you loose radio signal. if your battery takes a dump, comes unplugged, or the power switch gets turned off, the failsafe is useless, and you need the spring. if you feel the spring is slowing down the acceleration, you need a stronger servo.

 

[hamz9561]

If you are running the current generation of 2.4 GHz radios, most already have the have the fail safe already built-in. As Beason said, you do indeed need both the spring and a fail safe if your radio doesn't have one.

 

[olds97_lss]

Stronger/smooth servo, softer spring, different linkage setup that will push the carb closed vs relying solely on the TRS (throttle return spring).

This was my linkage on my old revo before:

Just pick up new piece of piano wire at your LHS, but a z-bend in the end and a few collars/springs, then you can adjust the linkage to hold the carb shut and get a more normal TRS than the traxxas one. Theirs is silly stiff.

I used a ball end on mine, but you can use a z-bend. The ball end helps keep slop out. Replacing the bushings in the throttle pivot with bearings also keeps slop out and makes the linkage as smooth as possible. I didn't have a TRS, but I should have. I ran a electronic FS, so I felt pretty good about it, although a softer TRS would help hold the carb shut and shut it completely. Without it and with that linkage, the idle had a tendency to wander a bit. I run both now on my current revo.

This is my current revo:

The TRS is a spring I picked up at a hardware store. It's strong enough to pull the servo back when power isn't applied. Which is all the TRS's are for. They aren't intended to overpower the servo... although, the traxxas one almost does with the weaker servos. On a stronger servo, it just puts more unnecessary load on it causing the servo to die earlier and drain batteries.

 

[Indian_Joker]

Stronger/smooth servo, softer spring, different linkage setup that will push the carb closed vs relying solely on the TRS (throttle return spring).

This was my linkage on my old revo before:

Just pick up new piece of piano wire at your LHS, but a z-bend in the end and a few collars/springs, then you can adjust the linkage to hold the carb shut and get a more normal TRS than the traxxas one. Theirs is silly stiff.

I used a ball end on mine, but you can use a z-bend. The ball end helps keep slop out. Replacing the bushings in the throttle pivot with bearings also keeps slop out and makes the linkage as smooth as possible. I didn't have a TRS, but I should have. I ran a electronic FS, so I felt pretty good about it, although a softer TRS would help hold the carb shut and shut it completely. Without it and with that linkage, the idle had a tendency to wander a bit. I run both now on my current revo.

This is my current revo:

The TRS is a spring I picked up at a hardware store. It's strong enough to pull the servo back when power isn't applied. Which is all the TRS's are for. They aren't intended to overpower the servo... although, the traxxas one almost does with the weaker servos. On a stronger servo, it just puts more unnecessary load on it causing the servo to die earlier and drain batteries.

Looks a whole lot better than the stock setup traxxas has. I was comparing the throttle opening and closing with and without that stock spring while the truck was off and I noticed a big difference in the speed it opened. I'm assuming I can pick all that stuff up at my LHS huh? Thanks for the pics. That helps out a lot.

 

[olds97_lss]

Yep. They usually have the threaded wire all in tubes somewhere. The heavier gauge stuff is better to use as it doesn't bend as easy when under load. If you want to stick with z-bends, I'd suggest getting a z-bend tool as doing them by hand never works out right for me. They look more like this: _/- I can never get the the upright part to be a good 90 with the top/bottom parts.