POLAND_SPUD wrote:Why are power requirements are mentioned only for no1 (2" and 10x mix) but not for the rest??
Smartarse answer: Because that's what got stated by the person who submitted it.
no3 would be something new when completed ... many people said it would be a cool to build a semi auto/full auto hybrid but it got only 1 vote
People may be mistaking what "working on a 4 stroke cycle" means. Some may be assuming that it needs to be built like a 4 stroke engine with a crank/motor driven piston, flywheel or some such.
Not at all. My auto hybrid uses works something that's functionally similar to a ICE cycle, using an idea I borrowed from Jo years back. (She posted it on Spudtech)
The chamber has a spring loaded piston that runs the chamber's length. When under pressure, the piston is pushed back to the far end of the chamber. After firing, pressure is lost, so the piston gets pushed back by the spring to the other end of the chamber, pushing out the exhaust gasses as it goes.
It's so simple, but so bloody f***ing clever, I really wish I could pretend I'd come up with it myself.
So, what I've designed is similar to a 4 stroke engine.
However, at first glance, it visually appears to only have 2 strokes (in that the chamber piston reciprocates once during a firing cycle)... not the case, because the fuelling and compression strokes are combined into one movement and the power stroke is directed at the projectile instead of the chamber piston.
The basics aren't really all that complex. The harder part is sorting out the valve system that controls the flow of both fuel and air as appropriate.