kicking roughly every 10 seconds should be sufficient, faster is of course always better
Then there's ample time for a reload
We've been using this one rated for 3V (http://www.tremba.de/zylindermagnete/db-zylindermagnete-ZMF-2551d.001.pdf ,datasheet in german tough ), but the shoot isn't that powerful.
Is it that one you have used with 180V, or at what voltage have you tested it?
We could still try to wind our own solenoid, gotta look through those coilgun sites...
If you have a spare solenoid to sacrifice, strip it of the old winding (measure the gauge/diameter of it) and replace with heavier wire - bifilar (or trifilar) winding will probably be best and/or you can make several sections along the winding length and make a number of complete windings to put in parallel.
I've stumbled upon this mechanism
I really like that idea for its simplicity We would have to use a worm gear to prevent the "bar" from sliding back and for additional power and probably some kind of position feedback like an encoder or just some switches.
What do you think?
I don't think that concept will work, as you need to load and lock
it, to be able to fire it at a precise moment.
You'd need lot more power than what is used in the video.
No need for encoders, just make a lock/release that signals when it's ready (loaded).
You could make something similar to a X-bow nut for the release.
What have you been using besides the solenoid for kicking the ball (i.e. the piece actually touching the ball)?
How much room is there in the direction of the kick?
Besides elastic bands (which would need to be very strong) and compression springs, a leaf spring may be a good option and may be easier to control.