Throttle return spring part two video

[McKrackin]

One of the members here is totally convinced it won't work so I made a video.
He then said it only worked because the heli wasn't running.lol....

I made a vid for you guys with the heli running.
It took a few tries to get it to close to an idle and not kill the engine completely.
If I want to kill it,I can just tighten the spring.
I used an adjustable linkage and hooked it to the shortest possible hole in the throttle arm so it has minimal tension.
It takes next to no tension to close the throttle....Yes,even running

[ame]http://www.youtube.com/watch?v=3UecUL_WA0Y[/ame]

Please post your experience with this.

[McKrackin]

Sorry for the big lag with dead air the first time I turned it off and back on.
I was waiting for the FBL to initialize.
I guess it takes a long time or maybe won't initialize running,sitting on concrete with no blades.Too many vibrations.lol...

[McKrackin]

[UPGl2AYDD]

Dude, that is awesome. To hell with the haters.

I gotta find a spring I got laying around to use for this exact purpose. Will be a fun "filler" project since I'm waiting on freakin parts.. Sigh..

[Lota Fun R]

That is a good test. "one test is worth a thousand opinions".

You have to agree that this needed a proper test and further testing is now needed. What if anything will change over time. Premature carb wear or servo wear or failure.


Definitely report back after some run time.

Having it adjusted the way you do is probably best to minimize the tension.

Me personally I would/will set it to shut off the engine but only enough spring to do that.


Good going.

[McKrackin]

Are you thinking the spring will wear out?

WTF?

I have a 1942 model tractor that still has the original factory springs on the carb.
As a matter of fact,that's where I borrowed this spring from.

There's the test and proof.
Any further stupid/useless tests will have to be done by someone else.
That's all I have to say about it.

[Wizzard]

No reason it wouldn't work, nitro car & truck guys have been using springs on throttle return for years.

Very sweet mod though

[Blink 182]

Cool, I personally wouldnt do this just because its not worth the trouble to me.

:

[TheBum]

You'd definitely have to go to a high-torque servo. The lightweight servos some people use on throttle wouldn't cut it.

[McKrackin]

A sub micro servo off a Trex 250 would be fine.

You have to try it to understand it.
The spring is not applying any torque at all on the servo.
Maybe a third of an ounce,tops.
I can move the throttle by hand with the spring on or off and I can't tell a difference.

The cyclic and tail servos are under a constant load that makes this spring nothing in comparison.

[McKrackin]

The stall speed of my servo is 10 kg/cm or 138.9 oz/inches.

That means the servo will stall when ten kilograms is hanging off the servo horn one centimeter from the servo pinion.That's 22 pounds by the way.

As luck would have it,my spring is 1/2 a cm from the pinion so the stall is around 40 pounds of pressure.

The spring offers less than an ounce of resistance.

Do the math

EDIT: These are torque measurements btw.
Don't be trying to lift 40 pounds with your servo.lol...

[Prontow]

The Anti-Chicken Dance spring!

[jamming]

gonna give it a try on one of my 700's I am also glad your first name isint Phil !

[invertsick]

Traxxas have done this on their tmaxx and revo trucks for years now.

they just use a regular analog 5 kg torque servo on their throtle.

but im sure with higher torque and digital servos this will work better.

i wonder why no one did this before

[Down Low]

As I said in the other thread, I am amazed a throttle return device is not mandatory at AMA/MAAC sanctioned feilds and events. Extremely cheap, simple and effective insurance.

DL

[ping]

I don't really see the need for something like this. In a radio lockout your throttle servo should return to it's failsafe. In a crash you should be hitting throttle hold as soon as possible. In the event of total RX power loss this would protect your heli, but that type of failure is very rare.

[flyinghigh450]

Originally Posted by ping

I don't really see the need for something like this. In a radio lockout your throttle servo should return to it's failsafe. In a crash you should be hitting throttle hold as soon as possible. In the event of total RX power loss this would protect your heli, but that type of failure is very rare.

If the link pop's off during a crash or battery eject's,you have no failsafe.

[Down Low]

You don"t see the point in a bit of extra safety? Guys, seriously, It's not the helicopters I'm worried about. They are nothing more than expensive big boy toys. Toys that are 100% replacable. Also. Murphy's law... If it can happen...It will. Eventually.

Simple redundency.

DL

[McKrackin]

Originally Posted by ping

I don't really see the need for something like this. In a radio lockout your throttle servo should return to it's failsafe. In a crash you should be hitting throttle hold as soon as possible. In the event of total RX power loss this would protect your heli, but that type of failure is very rare.

It happens more than you think.
Look at all the chicken dance videos.

Do you seriously think all those guys(even the pros)forgot to hit throttle hold?

When a heli hits on its left side,the linkage pops off pretty often.
Servos strip in a crash sometimes.
Batteries are ejected in crashes on impact.

The longer the dance,the more damage is done.

[McKrackin]

Dang...two posts while I typed one.lol...