Inversed Belt Reduction

I've recreated an inversed belt reduction first seen here: 

As I wanted to build this on my own I had to go through several iteration to get it to work. My goal was to get it as close as possible to the original one, but while I was building this, I came up with a lot of ideas on how to improve this designe. So based on this I will make a more usable version and improve what could be better in my opinion. 
For now you can make it for your own for the joy of building.

What you will need for building: 

• 4x M3x8 BHCS
• 4x M3X12 BHCS 
• 4x 608 Bearing
• 1x Nema 17
• 1x closed loop 300T-GT2 timing belt
• 1x 20T-GT2 Pully according to the shaft of your Nema 17

While the assembly is straight forward it is still a bit fiddly. 

See mine in 'action' here: