I built my custom 12v launch controller + clip whip (PICS!) =)

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Well-Known Member
Apr 12, 2004
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First up, here is my power source, a 12v lead acid battery in my RC car starter box:


Parts used for the build, all from Radio Shack except the speaker wire which came from Wal Mart:


The controller box after I drilled it out:


Buttons mounted:


Front of the controller. Pressing the black button arms the controller which lights the blue light and activates the buzzer. Pressing the red button launches:


Wiring detail:


Light and sound check:

Here is my igniter test. Three Estes igniters. And to make it more interesting, I strapped each one to a Morning Glory sparkler:


Here is my 3 ended clip whip:


Preparing the test outside:


All three Estes igniters lit without a problem. Unfortunately, only one Morning Glory lit. You have to hold a lighter on these things for a long time just to get one to light so I was not too surprised:


Full setup:


Now I need a good cluster rocket to really test with... :)
Originally posted by grimlock3000
Now I need a good cluster rocket to really test with... :)

I think the Deuce's Wild more than qualifies!

Nice launch controller. I like your buttons better.

Looking good! Has it got a saftey key though?
Nice controller Bushrat. I wish I saw that before I built mine, you have some good ideas in there.

IU would not find a momentary release saftey key so I built the controller without one. Right now I just have two momentary switches, both need to be held down to work. I am going to put a key in-line with the 12v leads right next to the battery once I find one.
It need not be a "key" as such, many people (including myself) have used a jack plugs as a safety key but your double switch system at the moment isn't really suitable and doesn't comply with any safety codes.

Jack plugs are very simple and commonly available, as all you need do is solder the two contacts in the plug togethor so when it's removed the ciruit the circuit is broken.

If you do find a key make sure it can only be removed from the "off" state, if you can remove the key and leave the cicuit armed it doesn't fit the criteria.

"If you do find a key make sure it can only be removed from the "off" state, if you can remove the key and leave the cicuit armed it doesn't fit the criteria."

That was my plan. Do I need the saftey on the controller itself, or can I put the safety on the battery box? If I put jack plugs on the wires going to the battery box does that count
The key needs to be where you can arm it immediatley before launch so the hand controller is best. There was a "lively" discussion on this sort of thing a week or so ago, I'd suggest reading it as it gave a good definition of what's acceptable for safety interlocks.


As for just using the jack on your battery box, not sure whether that would constitue as just "disconecting the battery" that was shunned in the above thread.

Guys, any views?

Also just to clarifly jack plugs I was refering to these things which Yanks seem to call phone plugs.
"My launch system will have a safety interlock in series with the launch switch, and will use a launch switch that returns to the "off" position when released. "

That is how I ended up with the dual momentary buttons. I was thinking when I let one button go, since it broke the circuit it was OK. I missed the "interlock" part. Now I feel kinda of silly with two momentary buttons :( No biggie, I am going to research a bit and wire up some additional stuff if needed.
Don't feel silly, a lot of controllers use the dual button set up. The Estes Command Control is one such animal. All you need to add, would be a 1/8, or 1/4 mono headphone jack, using the plug as the key. Just solder the leads together inside of the male plug, and that's it. For keeping up with the "key", I tie about a foot and a half of orange plastic streamer to the inside of the plug, slide it through the protective jacket, then screw the jacket on.
I wired some other stuff wrong too, my continuity check works even with the clips not attached. I made the whole setup more complicated than it needs to be. Glad I am testing all this out around the house before trying in the field. Off to Radio Shack again. :)

Thanks for all the help!!!
I used the same blue lamps on mine. Hard to see sometimes in daylight. Cupping the hand over it works though.

The rule of thumb on continuity lights is wire in in parallel with the launch button (or NO contacts on the relay). Seems kind of non-intuitive, but it is what closes the circuit to test continuity. The button (or NO Contacts) then short across it when the button is pressed to deliver full current to the igniter for the whoosh part of your day.