I regularly have to change from one filament to another depending on if its for work or personal use. I got fed up with how i had to pull my old holder apart to do this so i designed this easy load dual spool holder.
Note the one in the pictures was the prototype which i had to print an additional centre piece to thicken the central upright to stiffen it. The finished STL now include the thickened upright
There are two options for printing this holder it can be printed either in one piece (although would use a lot of support material) or it can be printed in halves. Each half has two locating holes in which locating pins (stl attached) can be used to line the two halves when sticking them together (this would be my preferred method for printing).