Most of the bits and pieces have arrived for this project, so I made a start on the machining today. I used 80mm dia aluminium rod to make the stepper motor support piece.
I cut a 92mm cylinder of aluminium, squared the ends, centre drilled a face, drilled it out to 25.4mm, shown in this photo. Note the 4 ribbons of swarf coming off the work. The drill bit is an industrial stepped bit, with 4 cutting lips. Then the hole was bored to 28.80mm.
Mechanicals finished. Now for the electronics.