Remote Throttle Kill?

[rmhoutz]

I'm looking for a cheap way to remotely disengage the ability to press the throttle. (Like they do at all the indoor go kart tracks for the general public.)
I know they make remote kill switches and I may end up going that route but since my Kart is pull start only I'd rather not have to keep starting it while my kids are learning. Anyone know how they do it at the indoor tracks? I can't tell if it's a spark interrupter or a mechanical disconnect but I'm thinking it shouldn't be to hard to rig something up.

Thanks in advance for any help or advice you can provide.
Ryan

 

[Tpdingo]

Most places nowadays are electric and that is just a wireless motor controller.

I'm going to guess you have a decent amount of electrical experience if you want to do this solution. If this kart is for your kids, I'm also going to guess the stock governor is installed(and that it is a Honda clone). Ok, what you can do is use a solenoid attached to the governor arm to pull on the throttle and turn the motor back to idle. Hook up the solenoid up to some wireless device and you can figure out the rest.

 

[itsid]

a remote mechanical disconnect is difficult but possible..
the downside is, a remote mechanical reconnect is MUCH harder.

and electric means you will have to kill the engine.
easiest is to remote trigger the low oil sensor,
(which is essentially the same as flicking the kill switch)

If you don't want to restart the engine every other minute because you had to remote stop your kid...

then trust your kids (most kids are very well able to obay a simply yelled "STOP!" command)

And if you need a backup for that, then we're back at remote cutoff.

There is one other option, but it's NOT emergency friendly I'm afraid.
You could install a servo just above the carb's butterfly,
that -if engaged- lowers a pin that in turn prevents the butterfly from being opened.
The downside is, if the butterfly is already open you need to make sure it doesn't lock it open (or else mayhem )
And if open it can't close it (the servo would need to be stronger than your kids leg.. which is uhm... not going to happen )


Hmm.. maybe if you instead have the servo unhook the throttle cable from the pedal *shrugs*
but I can't see that working reliably from on top of my head *shrugs*

Frankly.. killswitch and restart it'd be IYAM.. simple, reliable fool proof.. yes at the cost of some hassle restarting the engine.

'sid

 

[Tpdingo]

a remote mechanical disconnect is difficult but possible..
the downside is, a remote mechanical reconnect is MUCH harder.

'sid

If he has a welder and a bit of skill, this shouldn't be that hard to fashion up.
The piece at the bottom is a solenoid to push the engine rod up.

 

[rmhoutz]

Hi Guys

Thanks for the information. I'm thinking something like a small electromagnet like this.

Placed in between the throttle linkage rod and the throttle cable.
So as seen here.

Item 106 would have the electromagnet attached to the end and item 38 would have a metal slug attached to it. Since the magnet will be on a rod I'll get a tube for it to slide in when the throttle is pressed and when the magnet is released the metal slug on the throttle cable will be pulled back by the spring on the motor. I agree yelling stop should work but in my experience with kids on powerwheels it doesn't always work. They seem to freeze up and forget I can just take my foot off the gas.

 

[Tpdingo]

The only problem I see with that is the throttle cable I think will need its own return spring as the pedal won't be doing the returning for you and honestly I don't trust the one on the engine.

Also, due note that in the case of any malfunction, your kid will lose ALL throttle. Depending on the situation it could be potentially dangerous.

 

[mckutzy]

Why not something like this connect to low oil relay switch...

https://www.bmikarts.com/Remote-Engine-Shut-off-for-Non-12V-Vehicles_p_1219.html

 

[Tpdingo]

Why not something like this connect to low oil relay switch...

https://www.bmikarts.com/Remote-Engine-Shut-off-for-Non-12V-Vehicles_p_1219.html

Well he did say he didnt want to deal with the motor shutting off everytime he wants them to stop.

 

[rmhoutz]

Hi mckutzy

I agree that would do the job but honestly I have a 27Mhz Transmitter and receiver from my old RC car that has a range of 1/4 mile. I don't likely need that kind of range but I can see needing more than 250'

As far as loss of throttle since I'll be using a 3 channel radio and receiver I can still have a kill switch operated by servo.

I will need to modify where the brake pedal spring is located but that should be easy.
I just thought someone would have a ready made product that didn't totally kill the kart but you still could if need be. It sounds like it doesn't exist at this time.

 

[itsid]

If he has a welder and a bit of skill, this shouldn't be that hard to fashion up.
The piece at the bottom is a solenoid to push the engine rod up.

I like that idea (I watch Martin's MMX as well )
But I do see an issue with that.. sawtooth connectors tend to lock up under tension,
and worse the solenoid would have to move with the throttle cable in order to not lose it's leverage advantage.
if it's allowed to move it might tip over and instead of disconencting the tooth, it pulls the throttle open
So it had to be fixed to one of the teeth

but it gave me another very similar idea...

one of those quick release carbiners (a small keychain might do the trick)

Hard mounted to it's outside plate a servo or solenoid to open it
Somewhere inbetween the throttle cable.
(cut; one end tied in a loop to grab to, the other end tied to the carabiner)

A quality quick release holds a lot of weight while being easy to open even under high tension.
(well that might rule out a $1.30 keychain... but if you find one from Kong [hill climbing gear] you might have a viable solution)

And an old (broken?) rc car can donate it's remote and servo as well as the battery holder (so essentially most parts are free )

'sid

 

[Tpdingo]

I like that idea (I watch Martin's MMX as well )
But I do see an issue with that.. sawtooth connectors tend to lock up under tension,
and worse the solenoid would have to move with the throttle cable in order to not lose it's leverage advantage.
if it's allowed to move it might tip over and instead of disconencting the tooth, it pulls the throttle open
So it had to be fixed to one of the teeth

but it gave me another very similar idea...

one of those quick release carbiners (a small keychain might do the trick)
View attachment 101770
Hard mounted to it's outside plate a servo or solenoid to open it
Somewhere inbetween the throttle cable.
(cut; one end tied in a loop to grab to, the other end tied to the carabiner)

A quality quick release holds a lot of weight while being easy to open even under high tension.
(well that might rule out a $1.30 keychain... but if you find one from Kong [hill climbing gear] you might have a viable solution)

And an old (broken?) rc car can donate it's remote and servo as well as the battery holder (so essentially most parts are free )

'sid

I love Martin's MMX machine videos.

Definitely see where improvement can be made and the off the shelf quick release is probably the best idea. I think he could teach his kid how to put the throttle cable back in, as the release time needs to be quick, but not the reconnect, nor does it have to be done by a motor or solenoid.

I'm always in for a good old fashioned how the f**k do I make this work session.

 

[65ShelbyClone]

Well he did say he didnt want to deal with the motor shutting off everytime he wants them to stop.

It doesn't have to be used on the ignition. All the controller box does is open and close a circuit. Depending on what kind of switching circuitry it has inside, it may be able to control a relay or other small load directly.

 

[rmhoutz]

My Solution To Remote Throttle Disconnect

I'm always in for a good old fashioned how the f**k do I make this work session.

Sorry gentleman I know it's been a while since I posted this free shipping from China is not the fastest thing but hey it's free.

Anyway I just wanted to share what I did on this. My kids haven't had a chance to test it since the weather has gotten bad but everything seems to work when I test.

As mentioned in my earlier post I was thinking about using a electromagnet controlled by a micro switch that's controlled by a servo/receiver that was upgraded on my RC car.
Here are the pictures. (Admittedly I couldn't have done this without the machine shop or the 3d printer at work.)

 

[Tpdingo]

Great work....now if you could power the circuit off the engine that would be beautiful because now your kart has a "battery life". I'm assuming you made it so that the kart is failsafe and disconnects the throttle when it looses power?

 

[rmhoutz]

Hi Tpdingo

Yea it would be great if I could power or at least charge the unit off the motor but the electromagnet is failsafe by design since it requires power to keep the magnet attached to the slug pulling the throttle cable. The receiver and servo I'll need to watch, but the stock power supply was 4AA batteries. I'm using 2 18650 lipo so I'm thinking it will last as long or longer than the original batteries did and they would last quite a while and they were powering 3 servos.

 

[thatcrazydad]

What about a remote actuator flap in the airbox? It wouldn't be instant response, but it may also not totally shut the engine down either.

 

[Joe-405]

Electric linear motor that returns throttle back to idle when switched on remotely.

 

[rmhoutz]

Hi thatcrazydad and Joe-405

I like the ideas but I'd need to see the implementation cause I'm having trouble picturing it.

A few things I'm discovering during the development of this is,
1. It's hopefully a short temporary need.
2. Because it's temporary I don't want to make it too difficult to
remove.
3. It's best if it can be quickly bypassed for when I'm driving so I don't
have to turn anything on and use the batteries.

The solution I'm using for problem 3 is I've run a 2nd throttle cable that I keep disconnected when I'm not driving. Since the Predator engine has at least 2 throttle cable mounting options I keep both connected to the engine and just connect the bypass cable up to the throttle linkage rod when needed.

Thanks again for all the ideas and tips.