Search found 7 matches

by critical_al
Tue Aug 26, 2008 4:06 pm
Forum: Combustion Cannons
Topic: Mk 2 Rotary Barrel Semi-Automatic Combustion
Replies: 32
Views: 187412

The chamber is made from a Naval shell casing, WW1, along with most of the other brass work, all picked up off car boot sales for not very much money at all. The only major parts bought new were the barrels, 28mm copper as brass would have been ridiculously expensive. Some other small bits, like gas...
by critical_al
Sun Aug 24, 2008 4:53 pm
Forum: Combustion Cannons
Topic: Mk 2 Rotary Barrel Semi-Automatic Combustion
Replies: 32
Views: 187412

Not really all that expensive compared to some as all the brass is recycled, the main barrel is a naval shell case, all other brass tubes are also shell/cartridge cases, these were not much at all ( a few pounds each). Solenoids would have been expensive new but were cannibalised from other stuff. T...
by critical_al
Sun Aug 24, 2008 4:03 pm
Forum: Combustion Cannons
Topic: Mk 2 Rotary Barrel Semi-Automatic Combustion
Replies: 32
Views: 187412

Mk 2 Rotary Barrel Semi-Automatic Combustion

Hi, It has been a while since I last posted on here but finally ready with our latest pyrotechnic creation. This model was designed following the Mk 1 prototype - "Grape-shot", which I was very pleased with, but it was single shot only and very small gauge, hence the ammo of choice. This project gre...
by critical_al
Wed Feb 13, 2008 4:18 am
Forum: Combustion Cannons
Topic: Grape Shot
Replies: 34
Views: 9999

I completely agree with you
by critical_al
Tue Feb 12, 2008 4:23 pm
Forum: Combustion Cannons
Topic: Grape Shot
Replies: 34
Views: 9999

Grape Shot

Would love to hear what you think of this.
by critical_al
Sun Oct 15, 2006 3:34 pm
Forum: Combustion Cannons
Topic: Why not to use acetylene as spud gun fuel.
Replies: 77
Views: 36127

With a bit of fancy maths its relatively simple to work out, for a given volume combustion chamber, how thick the metal needs to be as long as its welded properly. Even with a suitable safety factor you might be suprised how thin it needs to be to contain the detonation. Of course if you are not too...
by critical_al
Thu Oct 05, 2006 3:25 pm
Forum: Hybrid Cannons
Topic: Jet gun - anyone did that?
Replies: 35
Views: 11108

Your idea sounds like a good one and should certainly be possible. It sounds like you are moving towards a pulse detonation engine which can be great fun to play with, although I've never tried firing anything from one! I don't know how much you have looked into them but a quick search on pulse-jets...