The Brass Gears supplied by the Association usually benefit from de-burring by the user BEFORE fitting into a mechanism. This is particularly an issue when meshing with plastic components, such as the worm used in the worm & wormwheel sets. The burr can shred the edges of a plastic component, rendering it useless.

Under strong magnification, small machining burrs can be often be seen on the edges of teeth, sometimes on only one face of the gear. Or, some will feel the burr with a very small flat screwdriver run along the face of a gear.

The suggested way to remove these burrs is with either a very fine cut file, or with a folded piece of wet&dry paper (probably more easily obtained for most). Very gently work at each corner of the gear tooth to remove the burr.

The burr is a consequence of manufacturing method: stocking gears where each one has been inspected and individually de-burred would raise the price of gears considerably, possibly by more than ten fold.

 

There is a Gear Meshing calculator on the 2mm Website for calculating the centres between gears, and Gear Mesh Tables are available in the 2FS Manual.