metal gears VS plastic gears

i am looking for gearing for my extruder, i was wondering how many people if any have tried or are using plastic gearing for there extruders, i have noticed that metal gears are not that cheap, but i would prefer it over plastic.

my rc car that i have from more than a few years ago has plastic gears on it, and for the most part they have lasted a long time on it, and with the motor that has on it they must not be all that week so i was wondering if any other people out there have tried any other gears besides metal.

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[mike-mack.blogspot.com]

The gears on the extruder that we're using were actually printed on Wade's reprap. So far they're holding up quite nicely, and I think that they'll last for a reasonably long time.

Real plastic gears should work too.

I have heard (but not have any personal experience with) Some of the newer plastics they use for plastic gears can wear better than metal gears and they even can have lubrication embedded into them so they are self lubricating.

Interesting layout, but you have to confine the fiber so that it will not spill off to the side.