Getting a grip

I am finding the components that require an interference fit of the shaft, keep slipping. I am using 1.5mm St St And drilled the hole a tight 1.4mm. I would like to see components that need to grip the shaft, have an integral boss to take a m3 grub screw. Or could you provide me the necessary files, to allow me to add it.

I am going to add to my clock some small magnets and hall sensors to provide feedback, to synchronise and lock to RTC.

I would like to have a twin stepper clock one for seconds and another for the minute train. That would enable self setting, from various time standards.

Thanks for some very interesting time projects.