which failsafe

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stiggysawdust said:
An unpowered servo needs very little pressure to return it to neutral.
therefore a biro spring is perfect. If you have not tried it then you just do not understand how it works.
It is the easiest and cheapest and most reliable method of stopping a runaway in the case of a broken battery or power lead.
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I would again disagree. My JR8711 is one tough servo to turn dead. Also again, if anything were to go wrong with the servo and it froze open I want to hit the off button or turn my radio off and know it will stop. i think we all know what your talking about and most of us tried it when there was no alternative but, technology has advanced and I will put my $2000 and up investment on the new technology on this one...:)
 
Bigger the Better said:
I would again disagree. My JR8711 is one tough servo to turn dead. Also again, if anything were to go wrong with the servo and it froze open I want to hit the off button or turn my radio off and know it will stop. i think we all know what your talking about and most of us tried it when there was no alternative but, technology has advanced and I will put my $2000 and up investment on the new technology on this one...:)
Click to expand...

totaly agree mate :cool2: for £35 in the uk i'd rather know i can switch off than rely on a small spring :no::no:
 
Time to put an end to the error

I think it is time for a reality check Stiggy... Do you honestly believe that a biro spring will return the throttle servo on a fifth scale car? Instead of just repeating your claim, how's about you (or your misguided cklub) actually hook up a spring balance and measure actually how powerful a spring you would need? I think you will be surprised at the answer. Now imagine applying that load against the servo all the time it is running! Nope, it doesn't make sense.....

stiggysawdust said:
An unpowered servo needs very little pressure to return it to neutral.
therefore a biro spring is perfect. If you have not tried it then you just do not understand how it works.
It is the easiest and cheapest and most reliable method of stopping a runaway in the case of a broken battery or power lead.
Click to expand...
 
If you bothered to read the post properly you will see a photo of my cars throttle return which works perfectly.
As far as I am concerned you can use what you like. You all seem to prefer your own advice.
 
Gents, put the buns down and step away from the Biro spring :hammer:

Stiggy, yes it will return throttle to neutral on some lower and mid torque servos (which I assume is what you have), but won't cover all eventualities for the reasons BtB states. We therefore can not recommend it to the masses because there is a better way which covers every eventuality. Also most 1/5 scales have ultra high torque servos which are difficult to back drive because of their basic design (high gear rato) and unsuitable for your mod.

The only way to be truely safe is to kill the engine. Even if you no longer have brakes, at least it won't go any faster. You can't easily do this remotely on a nitro, but is a doddle on a gasser with a £30 pico switch. You'd be daft not to.

In my personal opinion, no track should permit a gasser to run on it without a remote engine kill function which is demonstrated to work at every meeting. (People have a habit of acidentaly setting built-in failsafes to the wrong place when re-binding a 2.4ghz radio, which you won't know about unless it is tested every time). Nitro is a different matter and to some extent you have to accept a compromise with thease.

15kg + 40mph + marshal = broken bones (if you are lucky)

Don't forget the civil damages for reckless endangerment in a public place (for the three sports I do, I have a total of £18m public liability insurance, all of which have a clause requiring me to take all possible precautions to prevent incidents otherwise they will reclaim the damages from me personally).

:scared: Food for thourght :scared:

:offtopic: Anyway, like the man before said, killer bees are good, and the one off ebay seems to do the trick too :D
 
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The last big nitro race I was in I had qualified 4th in the a main. it was a big achievement for me against some stiff competition. I had a standard return spring that really was there just to show tech inspection. I had a futaba 9402 coreless servo. the spring wouldn't close the servo unless the linkage somehow popped off the carb. 2 of us at the same table had to use elastic bands as they were doing a serious inspection after the race. I can't tell you how many people it happened to but I know the bottom 3 finishers had to drop out because of burned out servos, myself included. to use a spring strong enough to close certain servos, it is a huge amount of strain on the servo to open them multiple times in a long race.
 
stiggysawdust said:
If you bothered to read the post properly you will see a photo of my cars throttle return which works perfectly.
As far as I am concerned you can use what you like. You all seem to prefer your own advice.
Click to expand...
Your car would fail tech inspection at any race meeting where I was a scrutineer. Your "solution" is dangerous, ineffective and likely to damage a servo if a strong enough spring is used. You seem determined that everone else except you is wrong. Just maybe you are wrong, but too stubborn to admit it.
 
stiggysawdust said:
An unpowered servo needs very little pressure to return it to neutral.
therefore a biro spring is perfect. If you have not tried it then you just do not understand how it works.
It is the easiest and cheapest and most reliable method of stopping a runaway in the case of a broken battery or power lead.
Click to expand...

Yes, but an unpowered servo is not the same as what a servo does during a radio glitch. During a glitch the rx can actually be telling the servo to apply full throttle. The throttle isn't just sitting there unpowered. The servo can actually be actively pushing the throttle open because the rx is glitching and sending a signal to the servo to apply full throttle. A return spring won't help during this instance.
 
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