6 replies to this topic

[Arthur]

I've made ball shells, some more successful than others! Now I'd like to have a go at a cylinder shell or two. 

 

Does anyone have any recommendations for a good YouTube video or a good tutorial anywhere else. My initial target is a 6" or 8" shell in September with colours and beraqs. Less interested in big flash charges, anyone can make a bang. 

[cmjlab]

I like this guy's methods for rolling a 3" case, filling, and closing. He uses time fuse instead of spolettes though, which I don't prefer, and if I were to use time fuse I prefer to glue it into a spolette tubes to make spiking a bit more reliable.. It all scales up though (minus former size and canulle size).

[cmjlab]

Ned's videos are good too, I like his spiking methods.

[cmjlab]

Lastly, since you can't "jumble fill" or use cut stars on a 6"+ shell, and expect it to reliably survive the lift, here's a good video from Ned as well on a 6" comet shell with stacked comets for a rigid wall.

[Carbon796]

Lastly, since you can't "jumble fill" or use cut stars on a 6"+ shell, and expect it to reliably
survive the lift.

While it's generally not recommended to build. 6" and above cylinder shells as cut star/dump filled shells. Saying that you " Can't " isn't really true. It's just a recommendation for best practices. 6" 3 brk + BS, cut star / dump filled, with a canulle. Were basically my go to shells for years. Usually with an inner and outer color, or a comet ring, or insert ring. It wasn't uncommon for some of those shells to be pushing 36" in length and 25+lbs, using more than a pound of hot pawlonia BP for lift. I never had a single 6" cut star type shell fail. Though you clearly cannot shoot those size of shells from standard type hdpe or fiberglass mortars.

For 8" shells I always made them as stacked comet outer's. Unless it was a purely insert shell. Though I probably wouldn't expect to have an issue building a single brk 8" as a cut star shell. I definitely WOULD NOT build a 8" multi that way.

Edited by Carbon796, 08 March 2023 - 02:27 PM.

[cmjlab]

I apologize for the miswording, you are correct - nothing I've ever read said you could not. It's generally not recommended in the literature I've read concerning cylinder shells due to the structural instability likely to occur from shifting contents during the setback of the lift, especially so when using larger cut stars such as spider stars cut for a 6" shell.

*Edit* I also believe you are correct in that it only really applies to single break shells. I've not made many single break shells since moving up to 5" and 6" so I've stuck to pressed stars / comets.

Context: I've only read Hardt, Fulcanelli and some of the AFN articles. I've not ever attempted to build larger than 6" shells at all, and haven't built a 6" with cut stars either, only pumped stars / comets / inserts. (In fact I prefer inserts now more than stars)

Experience: in my limited experience, I've found shells built with a wall of pumped stars / comets on the exterior to be more rigid than the cut star 5" shells I've made.

Edited by cmjlab, 08 March 2023 - 03:05 PM.

[Arthur]

Already having some 6" discs This may be the starting size!