As it happens older model Holdens tail-shaft are just the right size for standard aluminium drinking cans. One tail-shaft sawn in half would make two very good Can-Cannons. One can (we called the ignition/expansion chamber) had to be inserted all the way down with two holes drilled thru the tail-shaft and into the can. One for a rivet the other for ignition. Our propellant was methylated spirits. Any sign of liquid propellant and it would not ignite. So it was a just a dash then aerate a little. The projectile was of course an aluminium can, which looking back was a good thing as they were light, rather blunt and soft-ish so nobody sustained any real injuries (until one of us got creative with projectile and propellant). I mentioned this to my boss (a farmer) who was keen to see one in action and asked me to make one. At the same time it was just ready his young family just happened to turn up to the workshop. I pleaded with my boss that now was not the best time but he insisted. I again strongly suggested that it was a bad idea as it does go bang and will scare his kids but he insisted. It was a very loud bang (much louder than I recalled from previous experiments) and his kids ran away screaming. I was in the bad books for some time but my boss was impressed all the same. Justin On 8 October 2013 15:20, RussellMc wrote: > On 8 October 2013 17:14, Justin Richards > wrote: > > > Is it ok to discuss the details of a particular gas cannon I (and > friends) > > experimented with when I was young. > > > > That is propellant, projectile and construction. > > > I'd say sort-of / maybe, with due care. > I'm interested in such and there are lessons to be learned re safety, lif= e > experiences etc and even about just what it takes to do various things BU= T > we do not want to stray into anarchists cookbook territory (relatively > rubbishy fwiw) or how to xxx in vast detail (enough of that in graphic > detail on You tube. And we'd like to avoid things that people getting thi= s > on an at-work feed would blanch at. > > Bob is a bit more conservative on this than me (as he has a greater eye o= n > where such things can go) and other admins may weigh in if they feel > strongly enough. > > Start slow, be careful, watch for signals at the mast-head and see how it > goes. > > Odds are, anythingt 'instructional' re actual devices is easily outclasse= d > by what you'd find in 2 minutes on BinGool and the human interest factors > are the main draw. TBD :-) > > > Russell. > > Gargoyle: > > 846,000 Potato Cannon > Select images. > Wow. Agh. > OK. No shortage of DIY there. Pages and pages. > -- > http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .