Egg-O-Naut C

[rocketman1555]

yeah, ur right andrewwski, i forgot that there's usually snow around regionals, i've been in TX a little to long, so considering that, 10 minutes does seem better, i think they're just basing it off the bottle rocket rules, hopefully they'll change it later

[andrewwski]

Has anyone ever purchased/made a launcher before? I'm finding some online that I think will work (like these), but I've never tried them.

http://sciencekit.com/ig0024115/p/IG0024115/
http://store.ramfast.net/sc-17000.html

I'm also finding plans to make them...using a sleeve to hold ty-raps as a clamp over the flange seems popular...but by the time I get all the materials it may be more worth it to just buy one.

I'll probably set up a little base out of plywood. I'm thinking of attaching the launcher to the base, which then can be staked or weighted to the ground. I'd also have room for a car battery or maybe an alarm system backup battery if that's too big to power a 12v air compressor. My compressor's gauge is shot though, so either I'd have to some how piggyback another gauge on or get a new compressor. I think using a separate gauge would be more accurate than the ones that are on air compressors.

I'm hoping to get this event pretty much done before the cold.

[sachleen]

building your own launcher shouldn't be too difficult. you could just have a piece of wood to 'trap' the bottle at that ledge thingy below the cap and then yank that out and it would shoot up. I don't see the need to buy one.

[fleet130]

This might help: Building The Basic Bottle Rocket Launch Pad


Edit: Changed URL

[andrewwski]

Hmm...that's a pretty basic design that looks like it should do the job. I was looking at other plans like this, which are more fancy and complicated, but by the time I bought all the pipe fittings and everything I'd probably have already spent $30.

http://ourworld.compuserve.com/homepage ... cutube.htm

http://www.smoke.com.au/~ic/cable-tie.html

Plus, since this is from SOInc, it's probably similar to the ones that will be used during competition, which is a good thing.

Everything looks like basic supplies...no reason why I couldn't replace the countertop stuff with 1/2" particleboard or something.

[fleet130]

Many of these launchers have been built using common 2x6s and 2x4s. If you use something like particleboard, make sure it is made with waterproof glue, otherwise if will fall apart after a while. If you use plywood, it should be exterior grade. One drawback is that the electrical box can interfere with fin placement.

These launchers are fine for practice, but they're too slow to be used at many tournaments. Also, they don't have the bells and whistles you'll find on launchers used at most tournaments.

A few years back there was some consideration of standardizing launchers used at tournaments, but bottle rockets, in one form or another, has been around for quite a number of years. Most tournaments already have a launcher and some are quite expensive. Even if the rules were changed to standardize launchers, many tournaments would not follow them. Try to find out the specifications necessary to allow your rocket to fit on the launcher that will be used at your tournament.

[sachleen]

the launchers the teacher at my school has are fairly quick to setup, takes about a minute, probably less. i just hope the launcher at comp is simple and not something where you touch the wrong part and it blows up your rocket. lol

[andrewwski]

I've been thinking of ways to change the design from the SO site to eliminate issues with the fins.

I think replacing the metal box with a piece of sheet metal on the bottom would work. Then, two eye bolts could be screwed into the plywood (or whatever) to hold the clamp down. Therefore, there is no interference from the sides of the box.

I also found this one.

http://water-rockets.com/article.pl?117 ... pFlwHA9VhA

I really like it. It allows for you to fill the rocket after it has been attached, which gives you a lot more accuracy when filling the rocket, and keeps you dry. Unfortunately, I won't have a spigot anywhere near where I'm going to launch it, but I could probably rig something up to just drain from a 1 gallon jug or something.

Plus, unlike a lot of other launcher's I've found on the internet, it only uses common parts that I could find at a local hardware store. Sure, it takes a bit of plumbing, but it will be worth it.

The only issue is that you must cut off the little ring from the cap. But I don't think that's going to present any issue with another launcher either, so it should be fine for competition.

[sachleen]

wow, using those zip ties is a good idea. still think it's more complicated than it needs to be.

[andrewwski]

It might be, but it seems like it offers a bit more functionality.

By using copper plumbing a very accurate air pressure gauge could be put in. Or even better, a pressure regulator. You could just set it to 60 psi, and pump, without worrying about bleeding off extra air. Then theoretically you could even use a drum that holds compressed air instead of a compressor.

Only modification I'd want to make to that is find some way to add a quick disconnect valve instead of clamping the hose from the compressor on.