Launch Leads or whatever
The Thrifty Rocketeer continues...
As we approach Spring launch season in the mid-west, many of us are finishing up our winter build projects. Some are painting, and others are beginning to refurbish their launch equipment. Usually, this refurbishing includes replacing wooden clothes pins, replacing charred alligator clips, burned up blast leads, and occasionally, launch controller repairs
The typical rocketry club has an equipment manager who looks over these things and assures that they are replaced by the first launch of the season. For winter launch clubs, this might occur in the fall as the fields are winterized by the farmer/landlord.
The rest of us either have an old Estes launch controller, or have our own launch set.
But it occurs to me that as club membership changes and shifts, there's a need for many club members to be familiar with the equipment or at least how to set up and break down launch equipment. The temptation to launch alone might also prompt a rocketeer to set up his own gear... or at least, have a small set prepared in case something changes or is needed upon short notice.
Many of us have seen plans or photos of small launch pads built from either PVC pipe or from an old camera tripod. Just add a blast shield and a 3 ft launch rod and you're good to go for lower power launches.
But how many of us have thought about the power?
When I started launching, I carried a 6 volt battery and about 12 feet of twisted pair bell hook-up wire to start. ( I know NAR Safety guidelines recommend 15 feet, but as I was alone, and dipping my toe into the water, I cobbled something together.)
Today, I cobbled something larger together.
It occurred to me that I always drive my car to the launch site, and it sets behind the launch line as a supply vehicle in waiting. I know there's a 12 volt battery just setting there.
Now some guys are clever enough to build their own launch controller, complete with safety interlocks, keys, indicator lights, etc. However, for a solo single launch, that's probably overkill.
I have been impressed with how simply rocketeers have solved the problem of wires running out to the launch pad. Most rocket clubs have multiple extension cords that are normally used to carry 110 volt AC around the house or shop. But in our case, it just needs to be more than 15 feet.
So, I've invested in a 25 ft orange power cord, but I have nothing to plug it into. Until now.
I was musing over this dilemma when it occurred to me: I don't need to build my own. All I really need was a male and female socket on either end that runs to pigtails.
And then it hit me. What I was describing was a short 3 ft office extension cord. The kind that college kids throw out every year, or whenever they break their floor fan, or buy a new computer monitor, etc. In the case of a 3 ft office extension cord, all I would need would be to cut it in half. One half goes to the launch pad... the other half leads to the car battery.
Now, truth be told, if you use a power cord for a computer monitor these days, the female socket is shaped just a bit differently than your standard female power socket...and you're likely to have to wire one, or look very carefully through the trash/junk piles to find one.
I went to AutoZone and picked up a pair of battery alligator clips (big enough to grip a battery terminal) and a package of small alligator clips that will grip an igniter wire. I wired the small clips on the opposite end of the male power plug. I soldered the large clamp alligators to the opposite end of the female power plug.
When I lay it all out, I have a total of about 28 feet of insulated wire that will run from a car battery under my hood out to a single launch pad.
Can you spot the error in my thinking yet?
When connecting all this together, from battery out to the pad, I have LIVE 12 volts DC between the two small alligator clips. This is not good. This is why safety practice has you control the launch signal through a wired keyed launch controller box. The last thing you want is to be hanging onto those launch clips as you connect them live to your rocket and have it ignite with you sanding next to it.
For this reason, I have chosen a heavy duty female socket on the leads coming from my car, and leave the extension cord unplugged. For testing purposes, my control is going to be my two hands on either side of the junction, making momentary contact and then pulling them apart as the rocket lifts off the rod. At least, that's the theory.
In the meantime, I'm looking for simple plans for a controller to build...or for a used, damaged controller box that has at least one circuit working. Please let me know if you have any leads.
Until then, keep your glue capped, and your leads separated.
As we approach Spring launch season in the mid-west, many of us are finishing up our winter build projects. Some are painting, and others are beginning to refurbish their launch equipment. Usually, this refurbishing includes replacing wooden clothes pins, replacing charred alligator clips, burned up blast leads, and occasionally, launch controller repairs
The typical rocketry club has an equipment manager who looks over these things and assures that they are replaced by the first launch of the season. For winter launch clubs, this might occur in the fall as the fields are winterized by the farmer/landlord.
The rest of us either have an old Estes launch controller, or have our own launch set.
But it occurs to me that as club membership changes and shifts, there's a need for many club members to be familiar with the equipment or at least how to set up and break down launch equipment. The temptation to launch alone might also prompt a rocketeer to set up his own gear... or at least, have a small set prepared in case something changes or is needed upon short notice.
Many of us have seen plans or photos of small launch pads built from either PVC pipe or from an old camera tripod. Just add a blast shield and a 3 ft launch rod and you're good to go for lower power launches.
But how many of us have thought about the power?
When I started launching, I carried a 6 volt battery and about 12 feet of twisted pair bell hook-up wire to start. ( I know NAR Safety guidelines recommend 15 feet, but as I was alone, and dipping my toe into the water, I cobbled something together.)
Today, I cobbled something larger together.
It occurred to me that I always drive my car to the launch site, and it sets behind the launch line as a supply vehicle in waiting. I know there's a 12 volt battery just setting there.
Now some guys are clever enough to build their own launch controller, complete with safety interlocks, keys, indicator lights, etc. However, for a solo single launch, that's probably overkill.
I have been impressed with how simply rocketeers have solved the problem of wires running out to the launch pad. Most rocket clubs have multiple extension cords that are normally used to carry 110 volt AC around the house or shop. But in our case, it just needs to be more than 15 feet.
So, I've invested in a 25 ft orange power cord, but I have nothing to plug it into. Until now.
I was musing over this dilemma when it occurred to me: I don't need to build my own. All I really need was a male and female socket on either end that runs to pigtails.
And then it hit me. What I was describing was a short 3 ft office extension cord. The kind that college kids throw out every year, or whenever they break their floor fan, or buy a new computer monitor, etc. In the case of a 3 ft office extension cord, all I would need would be to cut it in half. One half goes to the launch pad... the other half leads to the car battery.
Now, truth be told, if you use a power cord for a computer monitor these days, the female socket is shaped just a bit differently than your standard female power socket...and you're likely to have to wire one, or look very carefully through the trash/junk piles to find one.
I went to AutoZone and picked up a pair of battery alligator clips (big enough to grip a battery terminal) and a package of small alligator clips that will grip an igniter wire. I wired the small clips on the opposite end of the male power plug. I soldered the large clamp alligators to the opposite end of the female power plug.
When I lay it all out, I have a total of about 28 feet of insulated wire that will run from a car battery under my hood out to a single launch pad.
Can you spot the error in my thinking yet?
When connecting all this together, from battery out to the pad, I have LIVE 12 volts DC between the two small alligator clips. This is not good. This is why safety practice has you control the launch signal through a wired keyed launch controller box. The last thing you want is to be hanging onto those launch clips as you connect them live to your rocket and have it ignite with you sanding next to it.
For this reason, I have chosen a heavy duty female socket on the leads coming from my car, and leave the extension cord unplugged. For testing purposes, my control is going to be my two hands on either side of the junction, making momentary contact and then pulling them apart as the rocket lifts off the rod. At least, that's the theory.
In the meantime, I'm looking for simple plans for a controller to build...or for a used, damaged controller box that has at least one circuit working. Please let me know if you have any leads.
Until then, keep your glue capped, and your leads separated.
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