I know this is from a long time ago but I have a similar project. I am trying to shoot a Dollar Tree rubber ball along a hallway about 20 - 30 ft with carpeting resisting it. Different than a golf ball which has a hardened coat, the rubber ball absorbs some of the strike. What kinds of solenoids do I ask for and where can I find them? The big sellers just want you to order from what they have, which is great if I knew what I was buying. TY in advanceUse a low resistance plunger solenoid with a non magnetic extension on top so that with a ball in cup the plunger is pushed down enough to overcome return spring, forcing a small magnet on bottom of plunger down far enough to close a reed switch. Solenoid is aimed slightly off center so that the ball does not fall back into cup. The cup has a curved bottom plate with a center hole so that ball will seat over solanoid. reed switch controls a MOSFET which can deliver large charge from large capacitor- charged from a battery bank or power supply.
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