good stuff

What is this yellow block you call rusz and where can I get it? Thanks

can you use the same process to polish delrin gears? or does this only apply to brass gears?

Why are you polishing the sides of the spur gear, this is only place that needs no special treatment the side do not rub or eea4 on anything. Windage losses will be nothing compared to the other frictional losses. I suppose it does look “prettier”. It is in fact the gear teeth face themselves that may need some attention to correct machine marking, . The axle you cleaned seems pitted. In some areas even after burnishing, and pitted. The “coloured” surface you remove is often a carbon treatment that may have lubricating or anti corrosion action.