The Purpose of this thread has changed (again). I have what I need, and am working on a working prototype, discuss my ideas if you wish.
Update - I have decided to base this project on my currently broken VSR. After doing much research I have come to the conclusion that a single solenoid valve will not have the opening speed I desire, so instead it will become a pilot valve to a piston valve system. I will spare the details of this system, but if you wish to know more send me a PM. If I am successful (or close to being) I will probably post a new thread w/ designs. The system will be run off regulated co2, in the 88gram cartridge form, which will give me more consistency than 12 gram cartridges. I will possibly play with the idea of having a temperature control system surrounding the cartridge to keep it at a consistent temperature. Now, before you comment on how it would be more economical to simply buy a gas sniper rifle, know this: I have gone beyond the notion of trying to cheaply repair my VSR by converting it to gas, I am now spending my money on what I believe to be an innovation in adapting spud-cannons systems to airsoft form. So, if you have a comment, make sure it's constructive. Thanks ASR!
Everything below this line is old ideas and speculation.
Imagine a normal Aeg. Take out the gearbox, motor, and wires. Leave the body and other externals, selector switch, barrel and hop-up unit.
Alternatively you could imagine a bolt-action rifle. Take out the triggermech, internals of the bolt and cylinder head. Leave the body and other externals, selector switch, barrel and hop-up.
Now a new system in the left-over parts:
You have a gas reservoir connected to a gas regulator.
The regulator is connected to an electronic valve.
The valve is connected to a feeding nozzle.
A motor moves the feeding nozzle in and out of the hop-up unit when appropriate.
All the electronic components are connected to a circuit.
The circuit includes a trigger (touch sensor), selector switch (rotation sensor), a battery, the feeding-nozzle motor and the main valve.
When the circuit is completed by the trigger being pulled, the main gas valve is opened for x amount of time, then closed. Then, the motor connected the feeding nozzle cycles to allow another round to enter the hop-up chamber.
The position of the selector switch (rotation sensor) dictates the amount of cycles allowed if any at all.
My question - Where and what valve is appropriate to performs the task? It would have to be able to open and close at a rapid rate, and if that was not the case than possible another valve that only opened when the pressure was high enough could be incorporated into the system. Also, what kind of setup could I use for the feeding nozzle?
What is not my question - What circuits I need - I have experience with normal electronics and minor programming to understand what I need, besides what's mentioned above.
The reason I would like to pursue a system of this type is because of the control the user would have over the rate of fire and velocity of the gun, allowing quick transition between cqb to other setups and visa versa. I would also be a simple, low-part and low-upkeep system.
Thanks for help, ideas and suggestions.