Here are instructions for a simple element for 3 knex balls. 1 ball stays in the element while it waits for 2 other knex balls to come until the whole thing tips over. It's easy to build and works about 90% of the time. You can always watch the video to see it in action.
If there are any problems/ questions feel fre to ask me in the comments below.
Thanks for watching/ building,
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