Current Projects chat and miscellany

the current design allow me to change the cog with less work than having to machine a new cog each time. and it allows for fine tuning the chain line in both directions with thin washers where the top hat would only go outwards.

You still have to modify each different sprocket, which is about half as much work as just making them from scratch with the top hat. Adjustability I concede, but why not get it right first time :-) ?