cryptochronic

So i went to my LHS and tried picking up a throttle return spring.. they said they dont carry them and they all just use a spring from a pen. I was able to rig up a pretty solid return spring in my opinion but im just not sure about how strong it has to be.. with the car off i pull the servo arm to wide open and it is not strong enough to pull it back closed. Is it supposed to be strong enough to pull thru the servo with no power or is it strictly in the event of linkage breaking

twomanytoys

It needs to be strong enough to close the throttle even with the servo. If you want something to prevent run aways then get a fail safe.

cryptochronic

i do have a failsafe (OFNA Mini, and Venom Smarttemp), i want a secondary measure. Thanks for info tho ill try to do sometin ill post some pics tomorow

breezerboat

I think the fail safe is only for if the controler goes out or you go out of range. The return spring is for if the batteries die in the car itself, which would be needed to make the fail safe work. So, the return spring would kick in if the car electronics stopped working. I'm correct right????

mazdaprotege4

My Feedback: (32)

I am pretty sure that a fail safe usually has a low voltage function that returns the servo to neutral if the voltage drops below a certain point.

yoster

Fail safes are an absolute waste of money. Run-aways hardly EVER happen from radio frequency issues. In fact in my 8 years of nitro, I've had a couple run aways, none of which were prevented by a fail safe. It is, absolutely in every case, the cause of not having a throttle return spring. What usually happens is some crazy landing, wreck, etc somehow manages to distrupt battery power to the receiver. When that happens, your fail-safe instantly becomes useless; it's all up to the throttle return spring at that point!

For a quick and cheap solution: http://www3.towerhobbies.com/cgi-bin...?&I=LXDTA1&P=7

dacaur

right. throttle returns spring will only help when the servo is unpowerd, like if your battery pack comes unplugged or something. An electronic failsafe only helps when you for whatever reason lose radio contact, and even then it will only work if its set up right...

As for the original question, yes the throttle return spring should be able to close the throttle from any position (not just WOT) with the radio off....

cryptochronic

Well i was able to rig up a semi descent return spring i think.. It does close it from wide open when i turn the car off holding full throttle. Not so sure in the design or strength but it works heh, heres some pics and a movie

you can see the 2 springs one by the carb and the 2nd one by the servo.. only works with these 2 in tandem

cryptochronic

heres a quick movie, what do you guys think?

dacaur

That looks pretty good.... did you have to stretch out the spings to make them work or did they come like that? if thats how they came you are fine, but if you streched the links apart (so that they dont return to how they were when you got them), that isnt a good idea.

cryptochronic

the one spring attached from the chassy to the carb i had to stretch a little bit because at first i was trying to make that one spring work alone so i put some tension on it before i screwed it down, is that bad? is it you think that they will lose there springiness? both the springs were from a clicky pen so i had to alter them a bit and dont mind replacing them.

dacaur

Yea, i would look for a spring with no space between the coils at rest (so its fully compressed at rest, then it gets space between the coils as you stretch it.

looking at your car, I would find one that you can attach to the throttle arm on the carb, wrap around the engine head, and attach to the shock tower.....

cryptochronic

ok, yea my main problem was theres really no place to attach the spring with it bending around something. I wasnt aware it would be okay to wrap around the head to shock tower, ill try lookin for a spring that would work.. thx