valveless barreless soda bottle

[iknowmy3tables]

gentlemen it's been a several years since I've last posted about a project in the works, but I was browsing this thread and some of the talk about special valveless rod projectile launchers reminded me of an old soda bottle rocket launch system I created when I was a TA for a shop class in high school. the launch system was just a schrader valve in a soda bottle cap with the walls slashed so the the cap would be held together with a pipe sleeve and a system to push the cap out of the sleeve so it would release the bottle. It occurred to me that this same system could act as the air seal and the the detent for a launcher similar to the grappling hook launcher kydavies is planing
so I created this prototype (pictures below)

I forgot to take pictures before the first test shot and as you can see the projectile likes to break itself on impact, luckily enough of it was intact for a second launch that I got on video


TL:DR WATCH THIS VIDEO OF ME EXPLAINING IT


so plus side is that this pretty much costs nothing to make and is only the size of a bottle, but the projectile has a short lifespan and takes time to make, I plan on using this for launching a grappling hook and maybe a spear head

[PVC Arsenal 17]

I love it. It reminds me of something I made last year.

This is begging for a proper quick-disconnect firing mechanism.

[iknowmy3tables]

the rod is acting as a sort of inside out barrel so to achive the same performance with a quick connect you'd need to make a custom quick connect with a large diameter sealing surface and long enough to extent into the chamber

[iknowmy3tables]

I'm not sure how well I explained all that so I made a short video to summarize it

also @PVCArsenal would you consider this a neater disconnect system

[jackssmirkingrevenge]

also @PVCArsenal would you consider this a neater disconnect system

I say just use commercial quick connects available forpeanuts on eBay.

[iknowmy3tables]

also @PVCArsenal would you consider this a neater disconnect system

I say just use commercial quick connects available forpeanuts on eBay.

a standard quick connect can't do the trick, the cross sectional surface area is too small and it can't accommodate the necessary rod that acts as an inside-out barrel

[jimmy101]

The release mechanism looks very similar to a "Clark Cable" launch mechanism used in home brew water rocket launchers.

[iknowmy3tables]

I remember this system, I made this type of launcher too when I was a tech ed TA, I had to machine the oring grooves with a miter saw

[Gun Freak]

Hey this is really cool... I think I'll try to make something like it