Prusa i3 upgraded spool holder

I found that the standard filament holder for the prusa i3 mark 1 and mark 2 were sub-par as it was very annoying to change rolls of filament and did not fit all of the rolls of filament that I have owned. This will also work for the mk3 as they all share the same frame. I simply improved upon the original design by replacing the knobs used to hold the filament with a pocket, and created a long rod out of a cylinder that was the same dimensions as the knob. This allows for you to place the two a