Introduction: Knex Ball Machine 'scissor Arm' Element
This element uses a 'scissor lift' geometry to move the ball sideways while acting at a small arm.
Attached is a small video of it in use.
Step 1: Scaffold
Here is the important part of the scaffold. Don't worry if it doesn't balance like in the first picture, as I added hidden unneeded pieces to hold it up.
Step 2: Pivot and Counterweight
Step 3: Scissor, Wheels, and Ball Holder
I have not tested other sized scissors, but if you do then you should build a further track in step 1.
After this step you are done! Good job