bluefluffybunny1

I think that this has been covered before but how do people generally fit throttle return springs to 1/8th buggies.?

I previously used a spring from a Savage 21 on my GS Storm (one end to the carb slide and the other to a tie around the exhaust but this is a little untidy.

It would be good if somebody would market a neat and effective solution but I don't think anyone does.

In case anybody is unsure why a throttle return spring is a good idea it returns the throttle if your throttle linkage comes undone or you lose battery power (which means that a fail safe will not work) and so stops you buggy crashing out of control and wrecking your engine.

Any ideas?

drf

Usually you attach one end on the carb linkage and the other on one of the engine holding screws. If you linkage comes undone the spring will save the day but if your battery goes dead or disconnected it wont. The spring wont be strong enough to return the servo back and you cant use a very stong spring that would do it as your servo wont last long.
It is really so simple that there isnt really any point for a company to market something like that.

bluefluffybunny1

If the return spring is the right type, tension and is set up right it will return the throttle if receiver power is lost. I have a Schumacher XTR which comes with one and that is exactly how it works. The problem is that the spring needs to be exactly right so that it will return an unpowered servo but doesn't restrict the servo too much.

Therefore the spring needs to be in line with the direction of movement of the carb slide and there is really nowhere obvious to connect it to on a 1/8th buggy and the spring needs to be right.

I have heard it said that o-rings work very well but need to be replaced frequently as fuel attacks them.

Any ideas?

Thanks

dbow

My Feedback: (1)

You can use just about anything as a throttle return. I have seen people use rubber bands and just about any spring of the right size can do the job.

Associated does sell a smaller throttle return spring, Tower carries it.

The best option is to run PCM or another type failsafe.


Dbow

bluefluffybunny1

The problem is that fail safes only work if there is power so if you lose a battery connection or yuor switch fails then you car crashes into a stream and the engine gets stuck at full throttle and destroys itself (it will never fail at idle...).

I want to make a neat and reliable throttle return for my MBX5 and don't want to make a bodge job!

Any ideas where to mount the spring, The fuel tank and engine mounts are at an angle so require a stronger spring to return the throttle which in turn means that the load on the servo is increased.

Has anyone found a good method?

dbow

My Feedback: (1)

I am unsure what failsafe you are looking at bunny but your statement in general is untrue.

The Futaba 3PJS has frequency lock out as well as a battery failsafe while in PCM mode.
I have been running it for years and never had a problem.
To my knowledge there are several failsafe systems out there that not only do the lock but also the battery failsafe.


Dbow

bluefluffybunny1

dbow, many failsafes will shut down the throttle if voltage drops due to low battery but they cannot do anything if power is lost (for example you lose a battery pack connection or the receiver switch fails). Try unplugging your receiver battery pack with the controller held with throttle open and you will see what I mean.

You are lucky that you have not had this problem. My GS Storm has decided to desert me on several occassions and luckily the bodge return spring that I had meant that it only hit things at low speeds.

maUru

i use a fuel line as a throttle return, it compresses enough to open full throttle - but automatically pushes back when power is lost

bluefluffybunny1

Fuel line over the linkage I assume. I understand what you are saying. Does it really manage to close the throttle? Also, do you get any problems with hysteresis in the throttle (for example when you return to idle does the throttle stay open a little until you close it with the brake?

fastfred

My Feedback: (4)

Bunny,

Can you post pics of your throttle return setup?

I'm in the process of getting a used storm setup, and am almost ready to run it. I've got a Dynamite Failsafe set up, but want to be sure about this you know.

Matt

bluefluffybunny1

I don't have any pictures but basically I got a throttle return spring for a Savage 21 and connected one end to the throttle linkage connector on the carb and the other around a tie round the exhaust. It worked but a bit messy. I'm sure there must be a better way but...