The Simplest Tripod
OK, here's a simple question.... What's the fewest number of legs a tripod can have?
Stumped at how obviously simple the question is?
Think again...
Let's ask it another way: What's the simplest launch tripod a rocketeer can make?
Not so easy, eh?
Let me assure you that people have been trying to re-invent the wheel on this one since Verne put the first match to a motor. (I know, it didn't really happen.... but they keep trying...)
Or put another way, to build a better mouse-trap. One that is simple, efficient, low-cost, and collapsible.
OK, so you can't have it all, but you can experiment.
I recently heard that the cheapest rocket launching rod was a coat hanger that had been straightened out and just stuck in the ground. That's it. Nothing more, period.
Now, not only do I not think that you can straighten a wire coat hanger out enough to get rid of the kinks where it was bent... but I think the risk of damage from rocket blast escaping onto the ground is something that Smokey Bear will want to discuss with you up close and personal, y'know??!!
I've also seen a number of various tripods made out of PVC pipe, of differing designs. One has four legs and looks like a saw horse or street traffic barricade. One is a series of legs that unscrew, and then reassemble to make a long straight pipe to store the launch rod inside. But neither of these is particularly cheap once you factor in the screw type connectors.
Speaking of cheap: I was recently told that the cheapest tripod is the one that you get from Goodwill. That is, those cheap, flimsy aluminum tripods that were sold during the boom in home video cameras from a couple of decades ago are now flooding the resale market. You can pick up a camera tripod with collapsible legs and clamping screw head for a couple of dollars. You might have to work to attach a metal launch rod to it and a blast shield, but it's one of the better sources I have heard of for a cheap launch tripod.
No, the most simple launch platform that I have heard of so far has just 7 parts... if you count the metal launch rod, a blast shield and a clothespin. The major component is a 3 foot or six foot long 1/2" PVC water pipe from your hardware store.
Cut it into three equal length "legs", (see what I did there...avoided telling you how long each of your legs should be for stability....) and then purchase ONE PVC connector.... a 1/2-in dia Side Outlet Elbow PVC Fitting [NOT A T-fitting!] That is, you're buying a single connector that would go into the corner of a box. Except for the length of pipe, this is the most expensive component, so get it right.
When you insert each of the "legs" into this connector, you can stand your new tripod on the legs and the connector forms the apex. Only problem is that you must drill a hole in the tip top of the connector to grip your metal launch rod, so choose your drill bit carefully. (You might also want to wait on this for a moment.***)
If you're really not confident in this PVC tripod, you could remove the connector, up-end it, and pour some quick cure epoxy into the bowl of the connector, and wait for it to cure. You don't want it to be so much that it fills the entire connector....you want to be able to get your "legs" in and out for collapsing. (But I suppose one leg could be permanently glued in place if you like. That'll make one less piece to worry about loosing.)
After you've poured your epoxy into the connector and let it harden, THEN drill your launch rod hole from the apex down into the epoxy. That should hold the launch rod at the vertical angle.
What? You say you want to be able to tip or angle the launch rod depending on the wind of the day? No problem: Just put a book or a large rock under just one of the tripod legs to lean the tripod slightly to one side. it's a temporary fix to a simple problem. You only need to spin the tripod so that the tilt is into the wind.
The blast shield is a simple ceramic pot OR terracotta pot dish for about a buck from Dollar General, or Family Dollar or whatever your cheap Dollar store is called. While you're there, buy a pack of cheap wooden clothes pins to clip onto the launch rod. These clothes pins burn through so fast, you'll want a whole package of them. They are used to keep the rocket lifted up off a metal blast shield when the rocket is in position on the rod.
By far, this is the simplest and easiest launch tripod that I have ever heard of. And the fact that you can remove the legs for storage and break it all down for transport or replacement is a plus. Just make sure that you have a blast shield in place so that the PVC doesn't melt or discolor, and you're good.
Of course, if this is too primitive for you, you're welcome to buy a launch set from Estes, or a clamping jaw vice from Lowe's and go nuts. But we said simple and cheap at the beginning.
And this has been the Thrify Rocketeer blog....
Remember to cap your glue and save your scrap balsa!
For those who have paid attention, it was specified in the copy that the pipe and connector be 1/2" PVC....however the photos show 3/4" PVC. It's been my experience that the 3/4" version is stronger, though it may take a little bit more epoxy to fill the well inside the junction. The 3/4" connector pictured cost $2 new. Some of the other pipe were recycled used, and a few legs look new. Use what you can.... -The Thrifty Rocketeer...
ReplyDeleteThe stand for an artificial Christmas tree can the starting point of a simple and cheap launch system.
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