[3DP] Big Gun cannons!

It will close just before firing.
The plunger will close and uncover a vent hole which allows air to pass into the breach.

 

ah thats what I thought, With the horizontal barrel you run the risk of loading multiple rounds if the ship is listing because the first ball could roll down vacating its position allowing another ball takes it's place. This potential issue can be solved by either reverting back to the straight up barrel like indiana guns or just have a steep angle.

 

I could probably even use a magnet on the plunger to keep the ball in place.

The reason I want to experiment with the horizontal barrel is because it takes less force to bring the ball to the barrel if it has momentum to make the turn up as opposed to being directly lifted by the air pressure.

 

hmmm I see.

 

yep, I bet a magnet would work to hold the round in place. It doesn't take much, and air pressure will easily be able to knock it off the magnet when fired. I like what you've got so far. looking forward to your results.

A few thoughts:
I don't see any ramps to help loading. Just having a hole dropping down to the breech will probably load inconsistently, bleeding off pressure through an unloaded barrel and weakening the other, properly loaded barrels. Something to watch for when you start experimenting.

Also, make sure that the breeches are normally open, and only shut when firing. I saw one cannon that worked the other way, only opening for a few seconds after firing, and it rarely loaded correctly.

Lastly, how easy will it be to do two, three, and four-barrel versions? And what is the smallest-diameter barbette they would fit in?

 

Right now it is set up to fit in a 3" barbette with 3x1/4 barrels. When I get a proof of concept done I can think about making different sizes and the challenges of that.