I made an Instructable for the second lift on my ball machine Grid Tower II. The lift originally had 8 arms, but I removed 4 of them to make it work better. Below are the video and a link to the Instructable.
Knextus’s Wheel Lift Instructable
-Knextus
knextus 
Is it going to replace the original one?
No.
We enjoy your posts and appreciate your instructions. Amazing work!
Thanks!