This is a ball gear version of the original wooden spool holder. As we had problems with almost empty spools, stopping the filament because it get tilted, we decided to built a more robust spooler system.
Print out all four parts using your Ultimaker. The part named "spulenhalter12-971" should be filled with around 90..100% to give it a strong structure. The rest can be printed with 20% infill. The rest is default except for the CURA (13.04) Parameter in the Advanced Tab Quality/"Cut off object button (mm)" set to 0.1mm and "Initiallayer thickness (mm)" to 0 (which means default 0.2mm layers). This results in more precise z-heights.
You need several M4 screws (20mm and 16mm length) some without top to fit into the sides (see images) and M4 square hex nuts. Then you need 2 ball gears with 22mm x 8mm x 7mm and a 8mm rod x 40mm(or longer) stainless steel.