[Vigilantcitizen]

"I do agree that sewer pipe is a poor choice."

I'm not a pipe guy, but would gas pipe, as in mains, be a better choice?

This looks like a fun project though I have a couple of improvements in mind.

First, an electronic ignition sytem, such as a model rocket ignitor system, would be far safer than a manual fuse.

Second, some sort of carriage type base, where the barrel sits on a slide and has springs similar to heavy duty trucks to absorb recoil. And, mount it all on a trailer with swing out down jack plates at the corners for stability.

The modeling portion of R and D starts tomorrow.

[Eaker]

I'm not a pipe guy, but would gas pipe, as in mains, be a better choice?

Pipe engineering and design is part of what my firm does. We build grass roots natural gas compressor stations.

Post 79 details preliminary specifications.

We also need someone to deterime if a 9.5" bore is suitable for a 8.6" bowling ball. Schedule 140 pipe would give a bore of 8.75".

Anybody here know which would be better???

[AnAmericanMother]

Back in the day when we were professional fireworkers, we developed a system to electronically ignite our aerial shells. We were the only folks using an electronic system - but we were the only working team that NEVER had a hangfire on launch. It either WENT or it DIDN'T (sometimes on damp nights our lifting charge wouldn't lift though). Other teams were impressed and some started using it, but most folks stuck to the old fuse-and-quickmatch system.

I wouldn't use a trailer - there's a lot more play in a trailer than you would think. But I think a permanent carriage system (probably some sort of cradle) would be a good idea. I wouldn't try to absorb all that energy - let Mother Earth do it - she's used to it.