Your dad's story reminds of my experience with the Krispy Kreme machine [0]. They have one at Daly City [1]. I remember going to see the first Krispy Kreme that opened in Canada since I lived within driving distance from it at the time. It seemed to me to be remaining part of fully automating Homer's Donut Hell [2].
Thank you for reminding me about this! I remember being mesmerized watching a few donuts go all the way through every time we stopped by when I was young. Sadly that location has been closed down.
[0] https://www.youtube.com/watch?v=Qu0ISv_GeHI
[1] https://www.krispykreme.com/location/daly-city
[2] https://www.youtube.com/watch?v=LtEFEdrrXc4