Launch Pad Leads

 The Thrifty Rocketeer blog continues...

It wasn't all that long ago that I posted about alligator clips and launch pad leads.  But I'm going to do it again.

Cause something minor has come up.

Before we start our spring launch season each year, we inspect our equipment and make repairs, improvement, corrections... to our gear.  This may mean new launch rods, or a new extension cord, or maybe clean and re-solder the alligator clips.

Now, it wasn't all that long ago that I was under the impression that there was only one size of alligator clip.  I was wrong.  There is a micro-size that I understand goes by the name "test clips" and is typically the size that you find attached to the end of the Estes-style launch controller leads.  Sometimes these clips have flattened ends, like a duck bill, to press flat against each other.   Sometimes the clips have small teeth to bite onto the ignitor wires.

More frequently, the next larger size is a more traditional alligator clip, with sharp teeth that bite and hang on. (If I keep this progression going, we'll eventually come to the monster 12 volt battery clamps of jumper cables, but I'll stop now.)

The point is that all clips become corroded and discolored.  Whether this is from the exhaust of a model rocket motor or perhaps just environmental humidity while stored over the winter makes no difference.  The corrosion needs to be cleaned off.

Typically, I'll use a spinning wire wheel or spinning grill-cleaner to scrub away that corrosion. It's never heavy, and the metal clips come up shining with just a few minutes sanding or scrubbing.

But sometimes, the clip has come off, or the wire has broken, or perhaps the flux that was used to solder it onto the end of the wire has continued to weaken the wire until it breaks.   That clip needs to be replaced or re-installed.

Usually this is not very involved, and just takes a few minutes.  But once in a while, the launch pad leads are so weak or worn that it might make more sense to replace the whole lead. Usually, this is just a lamp cord with male power plug on it.  Some call this "zip-cord" and plug.  But the point is that it's not a very expensive cord. 

Recently, I came across a three element power cord for an unused computer, and realized that it too could be made to serve, with fresh alligator clips installed.  The extension cords that we run from the launch controller to the launch pad is nothing special, just a bright orange power cord that runs  50 feet long.  But the point is that it also has a ground wire and so can accept a three prong male power plug as easily as a two prong lamp cord.

I realized that it was move-out week in our college town and a lot of the college kids just dump whatever they have acquired or been hanging onto...whether its a toaster that doesn't work any more, or a fan with broken blades, or a shattered floor lamp... all have power cords that can be salvaged.  To heck with the appliance... that's going out in the trash for the city to collect anyway.  So if the item doesn't work or has been abandoned, the cord can be salvaged with just a pair of side cutters. 

I made mention of this in our club newsletter and almost immediately got a response from a rocketry "Elmer" who confirmed that he had a lot of two-element power cords from long-gone laptops that could be donated.  So, there's another opportunity for power cords.  I thanked him for his offer and will probably take him up on it, should the number of lead cables fall due to attrition soon. 

So there you have it... a couple of sources for igniter lead cables... from an old lamp cord to modular computer cords.  You just have to keep your eyes open and score them before the garage truck/recycle-mobile comes around.

But the real challenge will be finding the right alligator clips in bulk...cause there's a million different styles by different manufacturers...and they list them all on electronic parts websites!

This has been the Thrifty Rocketeer saying, "Keep those clips shiny!"