I consider myself pretty open to hack jobs, but this one just does not make sense. You can find a super-cheap stamped cog for about $11. There is no way you will save $11 in materials, grief, failure, and work with any of these plans. Cheap cogs suck. But a cheap cog will be infinitely better than any work-around.
jim
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Cross Check Nexus7, IRO Mark V, Trek 620 Nexus7, Karate Monkey half fat, IRO Model 19 fixed, Amp Research B3, Surly 1x1 half fat fixed, and more...
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SB forever