Well done, YoungRichard- I'll have to pluck up the bandwidth to watch the video (dial-up) , but I had a similar moment of clarity after I diss-assembled an otherwise dead VCR.(That's Video Cassette Recorder,to the technically advanced). The mechanism which propelled the tape in and out of the machine has a nice little 12v motor and all the gearing to give a lovely gentle to-and fro motion to a dish or tank.
I think I will hook it out and see what happens..