Machining a Pulley From Scrap #shorts

This #SHORTS project was meant to be a quick and dirty proof of concept, but once it got going it turned into several hours of fiddling. Don’t they always? The material used for the pulley was an old die cast gearbox casing. It’s some sort of zinc alloy that is stiffer and harder than aluminium, but machines really nicely. I was just what I had to hand on the day. I dialled in one of the existing features on the metal casing as there was barely enough material for what I had in mind. Possibly a bit overkill, close enough would probably have been good enough in this case. If you're interested in the tool I used, take a look here: I took a preliminary pass and measured the resultant hole with a telescopic bore gauge. A few people have pointed out the technique shown isn't great. The truth is there was a nice close up of me deftly rolling the gauge through the hole, but it was unusably out of focus, and it was too late to re-shoot by the time I re