cheap as free bottle thingy
Posted: Wed Mar 05, 2008 8:52 pm
if your bored and are looking for something cheap too do with decent ballistic results, then here's a thread for you
this system came to me when I was building a water (bottle) rocket launcher in my tech class (the rocket itself was the project but being smart and knowing how to built pneumatics and o-ring seals resulted in me helping to build the launcher that otherwise would have been impossible or extremely crappy) so anyways the idea came to me that an extremely cheap and easy launcher could be possible by cutting the threads on the bottle cap and adding a second loose sleeve to hold them together so when pulled back the bottle would be released from the grip of the threads the idea became the secondary launcher complete with a spring loaded rod to to push the cap out of the sleeve with ease
its easy to make and you should be able to get everything free except the 1" pvc which you should just have as a spudgunner
heres a cheaper version I made at home it uses water bottles instead of fizzy drink bottles, just because I have more of them ,and my handheld pump doesn't produce much presure, also I can stick them in my backpack so i can shoot my water bottles if I want to whenever.
I added the screws just to help me pull the sleeve off
note the slots cut in the sides
the one I made is diffrent then one you will have for a soda bottle this I added and additional o-ring in the cap since cheap water bottles don't have fancy sealing faces like soda bottles
so you should understand how to make a cheap little launcher, first heat up and warp the 1" pvc so it fits around the cap of the bottle you'll be using its the only way I know to get a sleeve for bottle caps, then cut the edges of the cap 16 or more symmetrical cuts cut as close as you can to the plastic sealing face just don't cut it quick and you gets nice results with a band saw but you don't have to, razors and hacksaws work, if your using a soda bottle cap look for areas where there are three lines of threads running parallel I highly recommend grinding down the lowest of the three threads I have had bottles where the threads crack during the launch because those areas release too slow, grinding down the deepest part of the thread has fixed this for me, if you're using water bottles like me for some reason then not that you will need to add a sealing face for the bottle to press against but there is no problem with the threads. Now you add a schrader, you should know that you can usually get free rubber schraders from the guy that does your tires or your parents tires they are usually willing to give you a cheap schrader, you know how to do this drill a centered hole and push it in. now to launch just hold the outer sleeve and push the cap/schrader with both thumbs
if you do it right you get a very powerful launcher with better performance that a more fancy launcher with garden hose quick connects or o rings, nice bang and speed with air alone, of course you can fill it 1/3 with water for better trajectory performance but then you'll get wet of course
this system came to me when I was building a water (bottle) rocket launcher in my tech class (the rocket itself was the project but being smart and knowing how to built pneumatics and o-ring seals resulted in me helping to build the launcher that otherwise would have been impossible or extremely crappy) so anyways the idea came to me that an extremely cheap and easy launcher could be possible by cutting the threads on the bottle cap and adding a second loose sleeve to hold them together so when pulled back the bottle would be released from the grip of the threads the idea became the secondary launcher complete with a spring loaded rod to to push the cap out of the sleeve with ease
its easy to make and you should be able to get everything free except the 1" pvc which you should just have as a spudgunner
heres a cheaper version I made at home it uses water bottles instead of fizzy drink bottles, just because I have more of them ,and my handheld pump doesn't produce much presure, also I can stick them in my backpack so i can shoot my water bottles if I want to whenever.
I added the screws just to help me pull the sleeve off
note the slots cut in the sides
the one I made is diffrent then one you will have for a soda bottle this I added and additional o-ring in the cap since cheap water bottles don't have fancy sealing faces like soda bottles
so you should understand how to make a cheap little launcher, first heat up and warp the 1" pvc so it fits around the cap of the bottle you'll be using its the only way I know to get a sleeve for bottle caps, then cut the edges of the cap 16 or more symmetrical cuts cut as close as you can to the plastic sealing face just don't cut it quick and you gets nice results with a band saw but you don't have to, razors and hacksaws work, if your using a soda bottle cap look for areas where there are three lines of threads running parallel I highly recommend grinding down the lowest of the three threads I have had bottles where the threads crack during the launch because those areas release too slow, grinding down the deepest part of the thread has fixed this for me, if you're using water bottles like me for some reason then not that you will need to add a sealing face for the bottle to press against but there is no problem with the threads. Now you add a schrader, you should know that you can usually get free rubber schraders from the guy that does your tires or your parents tires they are usually willing to give you a cheap schrader, you know how to do this drill a centered hole and push it in. now to launch just hold the outer sleeve and push the cap/schrader with both thumbs
if you do it right you get a very powerful launcher with better performance that a more fancy launcher with garden hose quick connects or o rings, nice bang and speed with air alone, of course you can fill it 1/3 with water for better trajectory performance but then you'll get wet of course