This is an additonal Wheel and Filament Holder Adapter that allows using the small 1 Kg spools from RepRapWorld by using the adapters on the RepRapLogo and adding two 608 bearings to the RepRapWorld Wheel and mount as shown in the pictures. Print out two RepRapWorld Wheels and four RapRapWorld filament holder adapters. Press one 608 bearing into each of the wheels while they are hot off the printer (they just slide right in).Mount a RepRapWorld 1Kg spool in the exact middle of a 24cm long piece of 8mm threaded rod. Insert one RepRapWorld Wheel from each side with the 608 bearing facing out. Now from each side add an 8mm washer and an 8mm nut und tighten.Now add from each side an 8mm nut, 8mm washer and a RepRapWorld filament holder with the round side facing towards the spool. This should be brought as close to the spool as possible. Now slide one end of the threaded rod through the RepRap Logo hole in the Mendel Snap-in Filament Spool Holder so that you can then put the other end in the RepRap Logo hole on the other side. Center the threaded rod and then slide the RepRapWorld filament holder (aligned with the RepRap Logo hole) such that it snaps into the hole on each side flush. Now move then nuts outward until it exerts pressure on the adapters.Now from the outside on each side add an 8mm washer and an 8mm nut and tighten hand tight. Now use a wrench on each side of the left side and tighten the nuts against each other (not too tight) and then do the same for the other side.