I would like to use a small marble to push out liquid from a packet of some sort drop by drop. I don't know where to get started on this...All I know is that I need to somehow release a few drops of liquid from something small every few seconds. I was thinking of having a small plastic packet that has some sort of rubber o-ring thing that limits the flow of liquid to very little and a small marble's momentum forces the liquid out every few seconds. Basically the packet and marble are placed in a tube and the tube is pulled/dragged so the momentum/inertia of the marble on the packet pushes out the liquid.
In the below diagram the brown circle is a packet of liquid, red thing is some sort of rubber o-ring, the orange circle is a marble...When the hollow tube is pulled to the right, the orange marble slides to the left and presses on the packet...I don't know what these materials are called o or what other method I can use to accomplish this so all help is awesome!
twirap:
I would like to use a small marble to push out liquid from a packet of some sort drop by drop.
Maybe do a little research on how IV drips are controlled, both manually and with logic. There is some very simple mechanisms that control the flow. The trick is that there are often two controls. A coarse drip and a finer one. Trying to get to a precise amount directly out of a larger container is actually quite tricky.
A hypodermic needle on a syringe operated by servo/stepper motor etc sounds like a more predictable system, but it's hard to visualise this without knowing more about the type of liquid, how it's going to respond when you tap it with your inertial mass, or how convenient/easy it is to shake the thing around as you're suggesting.