Tutorial: 12V Electron Beam

With all of the recent questions about 12 volt controllers, I've put together a small tutorial on how to convert
an Estes Electron Beam launch controller to a 12 volt controller. Please wait till I've made the last post,
before commenting, or asking questions. I'd like this to be as easy to follow as possible.

Parts list:
Estes Electron Beam
30 feet or more of at least 16 guage two pair stranded wire (I used a spool of 50 feet)
Battery clips, miniature versions of jumper cable clamps (found at Wal Mart for less than a buck)
A low current, 12 volt lamp or buzzer (I used a Radio Shack buzzer, part# 273-055A)
Two small screws

Step One

First, the case for the controller will need to be taken apart. If you are lucky, you have an older one that was put
together with screws. If so, just remove the battery cover, and the two screws that hold the back panel on. If you
have one of the newer ones that's glued together, it will need to be cut apart. Remove the battery cover, then,
using a sharp Exacto blade, run it around the upper seam of the case a few times, until you have cut it apart.
Be careful not to press too hard, causing the blade to cut something inside the controller. Once you have it apart,
lay the two back panels aside, and place the controller in front of you.

Step Two

Remove the launch leads. This is done by removing one screw, which holds a strip with one lead soldered to it.
The other lead, which is soldered to a battery contact, is easily removed with a pair of needle nose pliers.

Step Three

Remove the lead attached to the brass strip, by heating the solder joint with a soldering iron, and set it aside.
The battery contact will not be needed. Now is also a good time to remove the micro clips from the launch
cables if you plan to reuse them. The rest can be discarded, or tossed in to your parts bin.

Step Four

Next, remove the other screw inside the controller, which holds a silver contact strip, a small spacer, and a
brass contact strip in place. Remove all of the internal parts, and lay them out on the table. At the battery
compartment end, there is another contact strip that can be removed with needle nose pliers, and discarded.
It is not needed.

Step Five

Decide how much cable you want to have for your battery leads, and launch leads. Since I used a full 50 foot
roll, I decided to have 10 feet for battery lead, and 40 feet for launch cable. Where ever you decide, the pair
of wires need to be split (NOT CUT!) approximately the length of the controller. This is also the time to decide
which wires will be positive and negative. My wire had one side that had a wide red strip, which I decided to
use for positive.

Step Six

Cut your positive battery lead close to one end of the split, and solder it to the small brass strip. Be careful, and
solder it in a way that will not interfere with the safety key operation. As you can see in the picture, I drilled a small
hole in the end opposite where the safety key contacts it, and soldered my wire there.

Step Seven

Now it's time to install the buzzer. Or, if you choose, you can just replace the light bulb with a 12 volt bulb of the
same size. But, for demonstration purposes, I chose the buzzer. On the top of the controller case, I trimmed
the raised edge off from around the bulb socket so the buzzer could mount flat. I test fit the buzzer, and marked
where to drill a small hole to feed the wires through the case. Be careful that the wires won't interfere with the
operation of the internal contact strips. I mounted the buzzer by roughing up the bottom of the buzzer's housing,
and the mating surface of the controller, then attached it with some CA. The negative lead for the buzzer will be attached to the long brass contact
strip. To do so, I drilled a small hole at the end where the bulb was, and soldered my negative lead in the hole.

Step Eight

The positive buzzer lead, and positive battery lead will need to be attached to the silver contact strip. For the
buzzer lead, at the end where the bulb use to be, I drilled a small hole, and soldered the lead in the hole. At the
opposite end of this same strip, there is an L bend in the strip. Being careful not to bend the longer flat part of
the strip, bend the smaller part of the L up some. I drilled a small hole in this smaller section, and attached my
positive battery lead at that point.

Step Nine

Getting it all to fit. Using my Exacto knife, I had to cut paths inside the controller for the wires to run. For the battery
leads, I drilled a hole in one corner of the controllers battery door. The opening for the launch cable leads will need
to be enlarged, and some of the internal "walls" will need to be removed. After getting your wiring routes cut out, it's
time to install all of the internal parts. Don't forget the launch button if it fell out! When you are done, your controller,
at this point should look something like mine in the attached picture.

Step Ten

At this point, if you are using a new version of the Electron Beam, you are probably wondering, how to reassemble
it. If you look inside the controller, there are two internal screw holes. Now look at the inside of the back of the case
and there are two circles marking where the screw holes use to be! Just drill in the center of the two circles, get a
couple of small screws, and reassemble the controller. You see, Estes didn't change their design on the plastic,
just their method of attaching the two halves together. Next, after feeding your battery leads through the hole in
the battery compartment cover, snap it back in place. You should now have something similar to the pic below.

Step Eleven

The final step. At the free end of your battery leads, attach the battery clips (red for positive). I soldered my leads
to the clips. On the free end of your launch cables, attach your micro clips. Now it's time to bundle up your wires,
and take it out for a test. For my test, I shorted my micro clips together, hooked my battery leads up, and inserted
the safety key. Nice loud buzz, Good! Then I grabbed an igniter, and hooked it up at the clips. Inserted the safety
key, got the buzz for continuity, pushed the launch button, and lit the igniter. Done!

I hope this little tutorial has helped. If it only helps one rocketeer get that cluster up vertical on all motors, it was time
well spent. And, I've got a cheap, reliable 12 volt controller to show for it!

The thread is now ready for any questions or coments.

Detailed instructions, good pictures, and easy to follow. I predict a lot of newbies will be following links to this tread. Where can I get an alligator clip / magnifying / third hand thingamajig?

Great Tutorial

Nice write up with pics. It would be cool if someone could start a FAQ thread with links to threads like this.

Excellent write up! Great pictures! This should be an article in Sport Rocketry or at least posted to InfoCentral at Rocketry On Line. Have you thought about sending it to either of these?

Bruce S. Levison, NAR #69055

Very nice! I wish that I had something this simple when I made my 12V controller.
Thanks, Joe

David,

great post ,easy to follow and good photos

Thanks all for the compliments! As I said, with so many recent posts about 12 volt launchers, and, cluster newbies, I thought it would help. Like I said, if it saves only one cluster flight from the dreaded "only one motor lit lawn dart", it was well worth my time.

Jeremy, for the third hand, I bought it many years ago at one of those traveling tool sales, Chuck Homier, or Cummins. It wasn't that expensive, maybe 5-10 dollars at the most, but it was money very well spent. As a matter of fact, I'm heading to one of the Cummins sales here in a bit.

Bruce, the thought of submitting it to Sprocketry never entered my mind. Great idea though! I might just have to go fly my newly completed Estes Thunderstar with it, grab a pic, and submit that too

For the buzzer I used, I'm sure a smaller one, that would look better could be found. I used this one because it's the only 12 volt buzzer the local Radio Shack had in stock.

To anyone considering the project, and wondering about the time needed. It should only take an hour, two at the most. It took me over half a day, due to my 20+ year old soldering iron finally giving up on me. By the time we went to town for a new one, ate lunch, went shopping for clothes, went to the movies, went to supper, went...................you get the idea

Originally posted by teflonrocketry1
Excellent write up! Great pictures! This should be an article in Sport Rocketry or at least posted to InfoCentral at Rocketry On Line. Have you thought about sending it to either of these?

Click to expand...

This looks like a good article for Essence's Model Rocket Reviews.

David that was almost exactly how I modded my E Beam to 12V! I wish you would have posted this a month or so ago! Great job buddy!

I had an extra e-beam laying around so I put one of these together this weekend. The only change is that I plan on staying with the light rather than the buzzer if I can find the correct bulb(Rat Shack didn't have one). It was extremely simple to do and I had no problems at all with the construction. If reading the tutorial leaves things a bit gray in your head it will all make sense once you disassemble the E-beam. Thank You for this tutorial it really made this easy.

I do have a question though. I was talking to a friend who studied as an engineer a few years back(he's is not an engineer by trade and is admittedly rusty). He expressed concern that hooking this up to a car battery would push some serious amps through the circuit and fuse the launch button causing a total meltdown. He recommended a current limiter be installed in the circuit. I'm definitely no electrical engineer so I don't know if this is a concern. Can anybody shed some light on this for me? I want to use this with my Scout Den but don't want a kid to hold the button down and ending up with a handfull of melted plastic.

Thanks!

I have several launches on mine...no problems at all.

You mentioned melted contacts sticking together and then mentioned a kid holding the button down. Those are different things, but they could result in the same problem.

The odds of the contacts welding shut (in the "LAUNCH" position as if you were still pushing the button, but you actually let go) are very slim. I've never seen it in decades of rocket launching with dozens of Estes controllers that were built for 12 volts as well as converted. The biggest problem is when folks wrap the wires around and around the hand held unit for storage. The wires act like a Boa Constrictor and push the launch button down and it takes a permanent set (thin metal strip inside gets bent). This will produce results just like your doomsday scenario: perfectly safe until you insert the safety key, at which point the rocket will launch.

I always test a controller at the beginning of the day to make sure the button is not stuck or the metal strip bent closing the firing circuit.

All things considered, and I've converted MANY controllers, I'm waiting to see what the new Quest controller looks like. If it takes me 2 hours to convert a controller, I could simply work 2 hours of overtime and buy 4 brand new controllers built for massive power delivery.

If you don't have a job or overtime, then convert away. That's why I still save every power cord from every lamp or other device I discard - I use them to repair or extend launch controllers as needed or when I feel like a fun project. "Fun" = more fun than painting the fence or doing plumbing repairs or other drudgery.

By the way, as far as melting the wires and needing a current limiter: The only way to melt the wires (and it can be done) is to use a car battery and short the micro clips against each other or through the deflector plate to each other AND to continuously hold the launch button even afte nothing happens and you see the wire insulation starting to smoke and melt.

If using a car battery, the motor should ignite INSTANTLY, so mashing the button down for several seconds is a bad idea. Even with clusters, if your power system is "good" for cluster, they should all ignite virtually instantly. If you fly clusters and you need to hold the button down and wait as one after another motor ignites slowly, it is "bad".

Originally posted by Rat
I had an extra e-beam laying around so I put one of these together this weekend. The only change is that I plan on staying with the light rather than the buzzer if I can find the correct bulb(Rat Shack didn't have one). It was extremely simple to do and I had no problems at all with the construction. If reading the tutorial leaves things a bit gray in your head it will all make sense once you disassemble the E-beam. Thank You for this tutorial it really made this easy.

I do have a question though. I was talking to a friend who studied as an engineer a few years back(he's is not an engineer by trade and is admittedly rusty). He expressed concern that hooking this up to a car battery would push some serious amps through the circuit and fuse the launch button causing a total meltdown. He recommended a current limiter be installed in the circuit. I'm definitely no electrical engineer so I don't know if this is a concern. Can anybody shed some light on this for me? I want to use this with my Scout Den but don't want a kid to hold the button down and ending up with a handful of melted plastic.

Thanks!

Click to expand...

One source of 12V bulbs, that is much more reliable than Radio Shack, is Sears, in the tool area. Most any good home improvement store, or tool store should have 12V bulbs. Just ask an employee where replacement bulbs for rechargeable flashlights are (like the ones that come in cordless tool kits).


And, as Fred stated, in many years, and many controllers, I've never seen an Estes controller suffer welded contacts. I have seen wires burned in half though.

Thanks guys. Definitely a load off my mind regarding the wiring. Now where is that rechargable flashlight?

Originally posted by Rat
...concern that hooking this up to a car battery would push some serious amps through the circuit and fuse the launch button causing a total meltdown...
...I want to use this with my Scout Den but don't want a kid to hold the button down and ending up with a handfull of melted plastic...

Click to expand...

We had our launch last Sunday and the controller worked great! I have no continuity check light yet but that really wasn't an issue. I did have both sets of clips short out while trying to launch a 2 rocket salvo though. The funny part is both rockets now have a bit of fire damage because the kid held the button down and the igniters got red hot before I knew what happened. A couple of new igniters and off they went.

Definitely a recommended mod!

Thanks for the help.