here are instructions for a very cool element! Its' really compact, easy to build ,works about 90% of the time and uses 2 knex balls. To build this element You'll need some special pieces (see step 1). If you want to see this element in action you can Always watch the video.
If you have any questions/ problems feel free to ask me in the comments below.
Thanks for watching/ bulding,
Step 1: Special Pieces You Need
If you don't have the black piece on the last picture, no problem It's not that important.