12V launch system for clusters & Copperheads and such

Hi folks,

I'm gradually working my way up the LPR scale, now entering the "near MPR" zone. I've gotten away with using the standard yellow Estes Electron Beam launch controller, of recent vintage.

In a previous thread, about a year ago, I modified one to be safe for use with Q2G2 ignitors by swapping out the incandescent bulb and replacing it for an LED / resistor combo. While I was at it I upped the wiring gauge and made a clip-whip. But I stuck with the 4 AA batteries. It worked fine for up to 4 Q2G2s...

So now that I've got my first Aerotech D and E SU engines, with ignitors that take more oomph than my AA-based 6V system, I decided to kick it up a notch.

I could have built from scratch but I have a couple extra Electron Beam units laying around so I decided to use one as a hand unit. Added a 12V jump start unit from Walmart, a cigarette lighter adaptor to plug into it, and better wiring.

Presto-change-o. I built it over the weekend and tested it today on a set of 4 Estes ignitors. POP. They all ignited instantaneously. While I like the assurance of the Q2G2s, I'd have no problem using this on an Estes ignitor cluster. It should handle the copperheads fine too.

I'll document what I did in this thread. It's not rocket science (boo, hisss :dark: ) but maybe someone will find it useful if they are considering doing something similar.

Marc

To do the conversion I bought some LED bulbs with built-in resistors that are drop-in replacements for the Estes controller bulb. This allows for a much lower continuity test current, which makes the controller suitable for the Quest Q2G2s.
They were like $0.69 each so I bought a bunch to make it worthwhile with the couple bucks shipping fees:

https://www.pinballlife.com/index.php?p=product&id=1174&parent=192

I also bought an auto battery jump pack from Walmart. I think this is the one; the key thing is that it has a 12V accessory port.

https://www.walmart.com/ip/Schumacher-XP500-Jump-Starter/15140203

Marc_G said:

To do the conversion I bought some LED bulbs with built-in resistors that are drop-in replacements for the Estes controller bulb. This allows for a much lower continuity test current, which makes the controller suitable for the Quest Q2G2s.
They were like $0.69 each so I bought a bunch to make it worthwhile with the couple bucks shipping fees:

https://www.pinballlife.com/index.php?p=product&id=1174&parent=192

I also bought an auto battery jump pack from Walmart. I think this is the one; the key thing is that it has a 12V accessory port.

https://www.walmart.com/ip/Schumacher-XP500-Jump-Starter/15140203

Click to expand...

I've got a battery jump pack almost exactly like that, that supplies power for dozens and dozens of launches at a time (including clusters). Just make sure you plug the charge module into the wall for a couple hours the night before you launch.

I soldered a cigarette-lighter plug into my ancient 1970s-vintage Estes Launch Control System and it works perfectly.

OK, let's get to it.

The first task, after removing the two screws on the back of the controller, was to cut open the glued-shut innards. I just used a sharp mat knife along the edges to score it, then pried with a medium-blade flat screwdriver. It drives me nuts that Estes glues these shut... even to change the light bulb it's a major operation.





I then unscrewed the screw holding the metal tab in the middle, and gently lifted it out. I didn't get a pic of this next step, but I pulled out the bulb which is held in a yellow plastic oddly shaped "not quite a disc" with a hole in the middle that secures the bulb. I then put my superbright LED bulb (with integrated resistor) in its place, and attempted to put it back together. But it didn't work.

The LED bulb is a bit bigger in terms of the space it takes up so it banged up against the clear plastic dome which is also glued in place (grr... ) making it hard to replace these bulbs.

So I cut the dome off!

Next I flipped it back over and removed the thin gauge wiring:



We're going to do better!



I picked this 16 gauge wire up at Walmart in the discount aisle for $2.

Also from Walmart, I got this lighter adaptor plug for a couple bucks. It was in the marine (boat) accessories section:



It has an integrated fuse; more on that later.

To be continued...

I next soldered the cig lighter adaptor leads to the wire. I had done a test to make sure I understood which lead was positive and which was negative, so that I could properly power the LED. Remember, LEDs only work when powered in one polarity. However, I later learned that these bulbs not only have a built in resistor but have circuitry to make sure the LED element gets the right polarity no matter which way you feed it.

So if anyone is following this, don't sweat the polarity if you are using these superbright bulbs from Pinballife.

I put sections of heat shrink tubing on before soldering, made my connections, then shrank the tubing. This tubing shows the individual wire tubing shrunken with the larger diameter tubing waiting in the wings.



For the lead from the power source to the hand controller, I made it about 8 or 10 feet. I then used a crimp connector with a circular end piece that I could screw down with the screw on the metal tab. For the lead that goes to the clips, I also used a crimp connector. The two open wires got soldered together:



At the clip end I made a whip. For convenience I used some of the short wiring that came with the original controller... a short length of narrow gauge wire isn't a problem, given most of the 30 feet to the clips is beefier stuff.

As you can see I used the original microclips, two similar microclips from radioshack (also smooth tipped), and one set of big honking aligator clips.

I don't use whips that often (prefer to twist-tie Quest ignitor leads together) but I find it useful to have multiple sets in case one clip breaks off while on the range, or in some cases the leads may be too short to all twist together conveniently. OR I might use Estes ignitors in some clusters, and a whip would be handy.




That's pretty much the build; later I'll show the test...

So then it was time to test it.

I decided to try it on a set of four Estes ignitors. If it could fire them all effectively simultaneously, I figure it could work for any purposes I'd likely use it for any time soon.

So I set up a set of 4 ignitors:



Then figured I could get better video if I set a black background:



Continuity light!



Next, I set my camera to movie mode and recorded the proceedings. Note that the cigarette lighter adaptor has a power light on it. The instant I fired the ignitors, the light went out. Blown fuse in the adaptor!

Nonetheless, all four ignitors fired to some extent. Here's the video:

[YOUTUBE]9TyqV8RukGs[/YOUTUBE]

As you can see from the video, one of them fired much less than the others.

Note that I have a whole separate thread on picking the right fuse for this system. The silly thing is I forgot to put in a correct fuse before this test even after exploring the issue in that thread.

Marc

I inspected the four ignitors. One of them barely lit at all, though close inspection of the video and the ignitor shows it did fire to some extent.

Not finding a 20 A slow-blow fuse, I used next a 20 A fast acting fuse. Note the original fuse was either a 0.5 A or 5 A fuse; it's hard to tell from it because I can't really read the rating well.

I put the 20 Amp fuse in, and with the same ignitors from the previous test still hooked up, hit the button. All four ignitors fired some more, instantaneously to my eye. I didn't have the camera running. I didn't realize that the pyrogen once partially lit wouldn't run to completion, as shown by the fact that they apparently self-extinguished after the first abortive test.

I held the button down in this second test for several seconds; the 20A fuse held fine. The bridge wires in the ignitors had all burned out by then; no contact light.

Finally, I decided to try again, now that I had a good fuse situation, with four fresh ignitors. This is where it gets really stupid.

So there I am, camera rolling, and I'm fumbling one-handedly with the launch controller trying to hold down the continuity safety key and prepare to press the launch button. As I started counting down, just before getting to "4" I accidentally hit the fire button MOMENTARILY. It's kinda hair-trigger compared to my other controller.

So, all four ignitors partially fire again. Here's the video:

[YOUTUBE]kr-JYpMDoUw[/YOUTUBE]

You'll see all four ignitors pop heartily at the same time then sputter out at different rates. Again, it was only the most momentary contact on the switch.

Without the camera running, I hit the fire button again, and all four instantaneously fired again until they burned out.

I'm considering the tests successful despite my fumbling attempts.

This thing will launch any reasonable cluster on Estes ignitors and with Quest ignitors I could go crazy. I assume it will also be fine for Copperheads and the like.

Can't wait to test it on the range...

Cool thread, thanks.

Hi Marc,

I am based in the UK and am just about to move up to firing a Viper IV with 4 estes D-3 motors, after only ever firing single motor rockets in the past.
We can not easyily obtain any ignitors apart from the Estes here in the UK.
I am on a bit of a buget so what create a firing system with the lowest possible cost.
Can you please confirm if a standard motorbike 12v gel battery would do the job wired in to an old estes yellow firing system?
Can I ask what the purpose of using the led bulb was and what impact changing the cigar socket fuse had

Appreciate you help resouces in the UK are limited

Kind Regards
Darren

I can't claim to be an expert, but I think it would work fine.

You would probably do well to replace at least the bulk of the wiring from the really thin stuff Estes provides, with whatever you can find off the scrap heap or local discount shop.

Also I'd have some concerns about the bulb blowing prematurely due to higher voltage.

But a 12V gel cell would be expected to work fine (comments from others reviewing this, please!).

The LED bulb with built-in resistor served two purposes: reduction in current used for continuity test, which allows the system to be used with Quest Q2G2 ignitors (they fire using much lower current than Estes ignitors, to the point where the regular Estes system even with 4AA batteries will cause them to ignite). Basically, the LED draws less current through the system than a regular incandescent bulb. Secondly, the bulb supplied in the Estes system is optimized for 6V and may burn out earlier if you switch to 12V.

The cigar socket fuse simply prevents me from drawing outrageous current through the system in the event of a hard short circuit. I swapped to a higher than supplied fuse to prevent premature burnout in typical use.

Marc