Radio controlled detination: working with servos

CookFX Productions

CookFX Productions

Well-known member
I've been putting togeather a radio controlled valve for a a project does anyone know how to work with servos? What I'm trying to do is take the servo out of a radio controlled car, and hook a selenoid valve into the servo so that when you move the controller it opens the valve. This in idea should work but I'm not to clear on where the valve wire should be hooked up, what needs to be done to the servo besides removing the gears and the housing. Anyone tried something like this? Any help, websites, ideas, skematics, whatever you have would be great.

Sinister
 
First, you must consider safety and inadvertent firing - You don't say what is in the pipe that this thing will be attached to, but I'm guessing you don't want to let it out before it's cue?

If so, don't use RC vehicle gear. Imagine what would happen if some kid started playing with an RC car on the same channel near you - if the device was intended to explode, you could potentially kill someone.

I would suggest using some kind of coded controller system, such as that made by Quasar (http://www.quasaruk.co.uk/acatalog/Remote_Control_Systems.html)
This uses a secure coded protocol (similar to a car alarm) so that the receiver will not fire unless it receives the correct code.

This, coupled to a Solenoid valve will run happily on a small 12v battery pack, and be extremely reliable.
It's also cheaper than hobby RC gear.

I use one of these devices to remotely fire cameras.

Hope this helps
 
Though I do like what you showed me, I Agree with Knox, nothing wrong with version 2.1. Its a matter of hooking a reducer up to the servo I found and the signal is fine. Yes other things can interfear. But Building from scratch is always fun. I may look into what you suggested if I can find it in the U.S. But I spent All Day and was able to wire it correctly to fire two valves from one controller, and now its just a few steps from wearing it.
 
I think your missing the point. If what you are activating could hurt someone you are taking a HUGE risk with someone's health using a non encrypted system. In many parts of the world you could end up in jail if someone gets hurt. If it's spurting blood or something no big deal, if it's some kind of compressed gas probably a fairly big deal if it's explosive it's criminal negligence.
 
How come I have to tell you? Can't I finish it and post the first trial runs, so you all can see what needs to be amped up. Yes its blood. And It's quite close to being done. I need to figure out if im using a bladder system, or a resvaur squirting set up. I've done both in past with other versions, but the bladders pose big problems always. And where can you get this quaser remote system in the U.S.A anyone seen it around. It would cut done on the space. And its allready in a box, though i am building out out of plexy.
 
You don't have to tell anyone. However you chose to post a question. A lot of people get hurt and maimed every year by folks doing things that they didn't think through. That is why you got a lot of questions about what you were doing, we don't want you killing anyone. To turn on a blood FX I don't think your going to have to worry too much about maiming anyone by stray radio signals. Have fun.
 
I think Noiz2 was trying to make the point that detonating something with remote control is prone to interference from outside signals and therefore could go off at any time in the face of anyone who is not expecting it. Cell phones can interfere and they are ubiquitous.
 
THe only thing ive been worried about this is cell phones setting this thing off, if i run into something like this to much i might look into something like the Quasar like Ben S suggested early in the post. I just figure that the possible locations im going to be shooting are going to be good enough for just an RC servo right now. All next to nothing spent on it.
 
If anyone is interested in the Quasar system, and can't get hold of it, I would be prepared to ship one out from the UK.

They operate on 433MHz, so you would need to check this is a license free band in your area first.
They currently cost £39 for a 3 channel version, and slightly less for 1 or 2 channels.

PM me if you're interested.
 
Totally missing the point. You can't run pyro on RF without coded transmitter and receivers.

Non-squib blood packs are a different matter depending on how they fire. Are you saying you don't intend to rig anything that fires explosively or by highly compressed gases (e.g., debris mortars)?

e
 
overlandfilms said:
Totally missing the point. You can't run pyro on RF without coded transmitter and receivers.
Click to expand...

My point entirely...
I would use either the 2 or 3 Quasar system, and wire the Rx in such a way as to make accidental firing impossible.
To make it fire, you would need to press 2 buttons simultaneously.

The Quasar system is extremely secure, as each transmitter has a unique number - the Rx has to learn a Tx's number before it will respond.

This is accomplished by a jumper on the Rx's circuit board which has to be shorted out to put it into learn mode.

Hope this clears things up a bit.
 
I see your point, but you replace the switchs on the RC controller with toggle, and add a relay to the board you get a clean fire, or clean enough for the time being and for what I'm doing. And 120 PSI is enough to explode a bladder. or flush blood out of a holding area.
 
hmm...
Good luck.
I wouldn't trust anything vunerable to outside signals,
my only experience with remote control aside from phones has been with RC planes and even there you can easily run into signal problems.

I know early cellphones used two radio bands one for the speaker and the other for the mic, but I think they've switched from analog to digital signals, I don't know how they would play into what you're trying to build.

When I drive past blast sites (tons of them along 44), they always have signs a few miles before hand to turn off all cell phones so maybe there is still some concern there.

Maybe if you had a manually toggled safety switch to even turn on the reciever, and then used/required two seperate frequencies to fire...

or used something that is off the usual frequency band?

The quasar system sounds interesting but I know nothing about it so I can't give any input about it.

But I'd be pretty careful about signal interference, the more variables that can go wrong usually increases the likihood something will go wrong.

It might not be a bad idea to talk to a pyrotechnician about it, or maybe someone from a model rocket or aircraft club.
 
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