Launch controller ideas?

I salvaged two 12 volt batteries from a discarded electric scooter yesterday and was wondering how I can use one of these to power a launch controller.
I also found an old Estes "Electron Beam" controller in my garage and would like to modify it to use with the 12v sealed battery. I've got a small tripod from a telescope and was going to rig up some sort of tilting head like on the "Plumber's Pad" on it to hold a launch rod. Anybody have any suggestions?
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First, verify the 12V battery is any good. If the scooter was discarded, there's a strong chance it had burned out, nearly useless batteries. But if at least one is o.k. (it should be able to light a car headlight bulb for at least a minute without dropping in brightness appreciably) it should easily hold up to a day of launching.
To use the Electron Beam controller, open up the case and shunt (connect) the positive and negative battery contact points with a short length of wire. Use wire with a conductor that is at least as big as the wires coming out of the controller. Use solder, don't just twist them on!
Next, cut ONE wire lead about 4 feet from the controller, peel it away from the other wire, and solder battery clips on to the two fresh ends. These will connect to your 12V battery.
Finally, replace the continuity lightbulb in your controller with an LED/resistor pair. A 470 Ohm resistor paired with a bright green LED capable of handling 30mA ought to be about perfect and bright enough to see in bright sunlight.
Make sure you orient the LED properly so that when the red battery clip is on the positive terminal, and black on the negative, the LED lights. LED's are polarity- sensitive, unlike lightbulbs.
This is just one way, I'm sure there are other equally good methods.
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Eric Rabalais wrote:

Here are some sites with controller schematics, and launch pad ideas:
http://www.commlinx.com.au/models.htm
http://www.nar.org/NARTS/mahler/ultra.html
http://www.uoguelph.ca/~antoon/gadgets/rocket.html
http://launchpad.hofle.com /
There is also some info in the FAQ about using large batteries for launch systems:
http://www.faqs.org/faqs/model-rockets/ignition-tips /
Ken
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On Sat, 10 Jun 2006 07:33:40 -0700, "Eric Rabalais"

Get a 6vdc relay and make a relay launcher using your electron beam controller to power the relay, and the relay to switch the battery current to the igniters.
--
Darren J Longhorn http://www.geocities.com/darrenlonghorn /
NSRG #005 http://www.northstarrocketry.org.uk /
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Check the batteries to see if they are still good. There is really nothing salvagable in an Electron Beam launcher.Find a plan you like, or design your own, and start from scratch. A telescope tripod is probably solid enough for a launch pad. Even a fixed rod will work there, since the tripod probably already has the ability to tilt and pivot.
--
Bob Kaplow NAR # 18L >>> To reply, there's no internet on Mars (yet)! <<<
Kaplow Klips & Baffle: http://nira-rocketry.org/Document/MayJun00.pdf
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As far as the tripod as a launch pad, I made a small adapter from a 2" piece of 1 1/4" diameter aluminum I had laying around. All the tripods I have seen have a 1/4-20 thread to attach to a camera bottom so I drilled a thru hole and tapped one end of the block to 1/4-20. I counterbored and tapped the opposite end with a 3/8-24 to fit the drill chuck threaded end and used a set screw to mate the two pieces. What I had is an adapter that could utilize a tripod as a launch pad and still left it functional as it was intended to be used. I also had a tripod that was not usable as a regular tripod so I just found a place on the head to drill and tap a 3/8-24 hole and used a set screw to mate the drill chuck to it.
If you are using a keyed type chuck I would also suggest using one of those rubber key holders to keep it close at hand and not have to search your field box for it.
--
Best regards,
Mark Daughtry, SR
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Hi Eric,
Here's a controller I designed. Good luck!
http://www.geocities.com/capecanaveral/orbit/2032/launch.html
Dan

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