My SB Launch controller

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Well-Known Member
Jan 7, 2004
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I built my own launching system in the past fall. I wanted a rack for several models because I got tired of the ol' Estes stands. I built this controller with two plugs. The first connects to 25' of wire leading to a 5 rod (3/16" and 1/8") PVC rack and the second plug connects to a 50' cable for a single Mid Power rod or High Power rail. The stands are not shown.

The launcher fits well in the hand. Power comes from an external supply. High Amp or low amp as needed. 12V system. Continuity Indication is from a 12V lamp with a Green cover, ( Works with Davyfire N28B's). Start button and Test button must both be pressed to 'launch' and bypass the 12V lamp. Power switch with a key includes a low voltage LED to indicate power on. (RED LIGHT).

Switches enable any combination of 1 to 5 rods having power on START so drag races are possible. A 6th switch enables the 2nd pad power.

All parts from Radio Shack except the plugs which are automotive trailer connectors for 12V supply. So far I'm very happy with it. More pics to follow. This first pic shows the power lea connected to a pair of lantern batteries. Any 12V supply works.

Can you post a schematic diagram and more details regarding your controller. Looks like a nice compact multipad controller. With the 12v it should be able to launch multi engine clusters. Is it setup as a relay controller with power source closer to launch pad?
Here is a scan of a schematic. All connections are soldered and then insulated with liquid electrical tape. The project box had holes and blocks cut out for the switches, lamps and wire outlets using a drill and dremel tool.

The intent was for model rockets. Light gauge wire was used (14 - 16 Gauge). For the 25 foot model pad line I have lit clusters of 3 2-amp igniters on a clip-whip by connecting to a car battery. The line can push that load without problem, a four motor cluster would work as well. Anything over 4 and I would be looking for a flash pan ignition.

I have lit 3 Estes ignitors in a drag race. All 3 lit at the same moment. I've not yet tried all 5 or even 4 for that matter. I use a high amp battery on drag race starts.

On the 50 foot pad 2 line I would adapt it to include a pad relay if I were using it for clusters of high amp igniters (greater than 2 Estes or 4 amps total) but anything going to that pad is using low current igniters that my regular set-up would light anyway. If I did simply add a relay the continuity test would not work and I would probably build an audio continuity indicator at the pad.

If I need a HP pad for something where I want to be more than 50 feet away the relay and power at the pad is a must and is beyond the scope of this controller.
Here is a picture of my stands used with the controller.

1. 5 rod model stand. PVC construction. 1.25" parts. disassembles for storage. Rods are stored inside the main tube. Will accept 1/8" or 3/16" rods in any position.

NB - I'm looking for a good method of securing the rods in position. Right now they just friction fit into blind holes inside the pipe. They do come loose and with use will wear to the point it won't hold at all.

2. 1 1/4" rod stand. PVC construction. This also disassembles for storage. The rod is stored in the tube of the other stand. Actually it sticks out the end of the pvc tube when stored.

3. HP Rail. 10 feet tall. Breaks down into 2 5 foot sections and the folding steel stand. Rail is similar to 1515 Aluminum and uses the large size buttons (1500 series)
I made a change to my multipad launch controller this week. Until now I was using a couple lantern batteries or a booster pack for cars as my power source for my controller. I was getting tired of packing the power source separately so I started looking for alternate power sources that I could attach within or onto my controller.

Last weeks Canadian Tire sale flyer had a 12V cordless drill for just $17. I bought it and proceeded to unassemble it. I removed the switch, chuck, motor and then I cut the whole top part right off with the dremmel. I was left with the handle and battery attachment. I sanded the top of the handle flat and smooth and then glued the handle to the bottom side of my launch controller after I soldered my original battery connect to the new battery clips in the handle.

The drill came with 10 1.2V NiCd cells, each with 1300mah of power so I should get quite a few launches from this battery pack. The drill also came with a really compact charger that I keep in the range box with the controller. I tested it on a single estes igniter and it was good. Latter on I will test it on multiple igniters. I expect it will light at least 4 without a problem but I'll post again if it does not.

I knew a Jobmate would be good for something. (You probably have to be Canadian to get that). Now what to do with a nice little 12V motor, the chuck, and that case looks usefull too...
Holy back bacon, eh?
Or something like that.
That there is kind of ugly in a stinky wet beaver kinda way.
But if it works.
Cool with the handle though.
Looks great! How did you connect the wires to the trailer plug connectors? I can only find 4-wire connectors locally. Thanks.

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