Smart spool holder

I designed this spool holder because i need to change filament often and fast (is a boring activity... you know)
This holder can handle up to 100mm spool width and a little more.
Print all parts 2 times.
Ball bearings are needed, four pieces of 10x26x8mm, easy to find around the web, amazon or ebay.
For best results the bearings have to be very smooth, so if you want, clean with acetone or petrol, then use a liquid lube, like vaseline or something like...
Under the brackets you can stick si