14 replies to this topic

[toyboy]

Hi there,
I help to run an airsoft site (airsoft is somewhat similar to paintball, I believe it was explained in a previous thread), and pyrotechnics play a major part in the airsofting experience.
Currently, I am using a simple wired remote detonator to fire the pyros. It is just a control box, with switches that send a 9v signal down whatever length of wire to a relay, which switches a lead acid battery which is short-circuited with a thin piece of copper wire, wrapped around the base of the fuse on a crowscarer.

I have had no problems with this setup, it fires every time, and the copper wire used to light the fuse is very cheap ('borrowed' from a small motor actually) and very easy to prepare.

However, I am finding it rather tedious having to reel out huge lengths of wire each time it's used, and I'm unable to plant multiple explosives in different positions, due to having a limited amount of wire to use, as the site is fairly large, so to have the pyros positioned where I would like them would require several hundred metres of wire.

Anyway, apologies for the lengthy introduction. What I want is a multiple channel RF remote detonator, and several receiver boxes that I can plug into the relays, to fire the crowscarers with my current setup. (i.e. Lead acid battery, copper wire)
Cost is an issue here. While I do not have a specific budget, I would like the cheapest reliable solution. A fairly small remote control would also be preferable, rather than a large box, as I would like to be able to keep the detonator on my person.

Sorry for the long read!

Many thanks,
Graham

[Rogue]

I think the primary concern, as always, would be safety. With a wired system you know who is holding the control. With a basic RF circuit, there is always a risk of interference that could either (i) prevent the signal triggering the remote unit or, more worryingly (ii) trigger the remote unit without you intending it.

There are RF circuits that should help reduce some of the concerns through pairing. I would imagine that you could start from some RF encoder/decoder pairs such as the RF600, from Maplins or Rapid Electronics. Beyond my current skill to say how you would build up a suitable circuit from here, but maybe a starting point for research?

Would it be feasable to lay out wiring to some key junction points on a permanent basis? Then the devices could be connected to these as required, limiting your setting up to a few meters of wiring per device each time? May end up a bit safer and more reliable as well.

[karlfoxman]

I dont know why you cant use a relay with small high capacity batteries for each pyro device. Then you only need very thin wire like bell wire to trigger each relay with 6 or 12v.

[Big B]

This is perfect for you my friend :

http://cgi.ebay.com/...9QQcmdZViewItem

The distance is approximately 500m!
This guy can encode/decode the remote to fit the receiver.
Here is a link to his ebay store:

http://stores.ebay.com/e-MadeinCHN

Personaly I have this:

http://cgi.ebay.com/...I...p;rd=1&rd=1

[BrightStar]

Can I just add that with proximate pyro on a film set, stage or battle ground sim it is essential that you have line of site to the effect when firing. You might well have a 500m radio remote to trigger a maroon when the game is won, but you MUST be able to see that it is clear before you do so...

Non-pyros can be remarkably dim - I once had an actress (who I had thoroughly briefed) kick a stage flash pot because it 'hadn't gone off', oblivious to the fact that her position (almost on top of it) had prevented me firing...

Edited by BrightStar, 24 January 2007 - 03:10 PM.

[madtrickdotcom]

Bright spark remote detonation systems are meant for visco fuse, they ignite remotely and you can set off up to 6 at one time.
brightspark.co.uk
they only cost £20! I have one myself, and they are very safe.

[paul]

So, I asked the chinese electronics guy a few questions regarding the circuits he offers @ ebay. (Big B mentions his shop a few posts above!)

I got a link to his circuits where you can find pdf´s about them: http://www.e-madeinchn.com/

I guess the most secure option for using these circuits is the following: http://www.e-madeinchn.com/RM4SGR.pdf
It uses code hopping and thus is far more secure than a fixed code system.

There is a discussion about these items, as well. Have a look here

I´m going to buy the unit mentioned above and add a few security aspects.

First: A key switch to activate the firing outputs
Second: A turn-on delay which activates the reciever about 30sec. after applying voltage to the circuits. This is enough time to get away.
Third: Low current diodes to test the e-matches
Fifth: I will use thyristors instead of (shock sensitive!) relays.
So noting will happen if someone bumps into the firing box or if the firing box drops to the floor or something.

What do you think about that idea?!

Edit @ madtrickdotcom: But surely you won´t re-buy the ignitors for 10GBP/5pcs., will you?!

Edited by paul, 11 April 2007 - 05:35 PM.

[Caramanos2000]

I made something according to ideas from this thread. Here it is:

It has 2 9v batteries in series. I tried it with 100' of wire and it still worked so, Im good to go. I use some nichrome or a strand of steel wool, obviously better in the price aspect. To try it out I rigged up a 3/4" Bp Salute:



And fired it:
http://s104.photobuc...nt=PICT2375.flv

Edited by Caramanos2000, 05 May 2007 - 09:16 PM.

[dr thrust]

hi how long do the batts last? ive been useing car batts and iam cheesed off with the weight! ive now got a small lead acid batt like one from maplin check out ther oneline store,drool,drool,but they have a limited shelf life and youve got to remember to charge them!,i would like something small that i could toss away, replace come bonfire night last year my batt died! i am trying camera flashes but no luck. any chance of a batt life "test" you know 10/20 fireings them by by thanks.if it works i will build one myself

[Caramanos2000]

I have used it over 40 times remember it only takes an instant of power to light the wool.

[dr thrust]

thanks just got six 9v batts for two pounds! from the" local pound shop"cant decide which is more fun ,series or parallel,hmm sizzle sizzle

[cooperman435]

thanks just got six 9v batts for two pounds! from the" local pound shop"cant decide which is more fun ,series or parallel,hmm sizzle sizzle

Depends what you want? higher voltage or higher amps per hour.

series will up the voltage whereas parallel will up the amps available

personally I like to make sure everything works first time so I have 2 banks of batterys delivering 36v each connected in parallel to juice up the current.

[dr thrust]

got any nice pics! thanks,chris

[cooperman435]

got any nice pics! thanks,Chris

Theres loads on my web page of the firing box and its add ons (linked to my signature)

[johndee]

That's a very nice looking firing box, I liked the recycled no parking sign.