Nexus Charging Station

I work in a school, we have 50 Nexus 7 tablets. I designed this to charge 10 at a time. The stands accomodate a Nexus 7 in a gel case. The box part houses a 10 port powered USB hub with PSU. I got a hub from Amazon that uses a 4amp PSU, if left overnight it charges all 10 Nexus's to 100% but I'd still recommend a PSU with a higher amp rating. Get 10 short micro USB to USB cables to prevent clutter. I made the top and bottom of the case from 3mm acrylic on a lasercutter because I can never get a