A strengthened version of Antiklesys' feeder improvement. A must for retraction.Antiklesys' modifications is a great idea, but there were some concerns in the comments about its strength. There was very little could be done within the existing 4mm wide gap the part sits in, so to make it stronger you also have to change the side supports, part 10A and 10C. This is a fully printable upgrade of all 3 parts of the assembly, whilst keeping faithful to the Ultimaker original, using the outer shape taken from the lasercut drawings published. You will need a 6mm ID, 10mm OD, 3mm wide bearing, this cost me £1.99 on eBay.This thing really works. It reduced the friction considerably, meaning less pressure needed, less teethmarking of the filament, less jamming of the deformed filament in the bowden, less grinding the filament (none in fact since I fitted it) and much better, quieter retraction performance.Modelled in Siemens NX8, printed 0.1 slice, 100% fill using Cura. No support needed.