Tom, I always seem to end up with something in the shot for a "sense of scale" I did an earlier video test on the bench with an empty beer can riding up the conveyor, that should give a real good idea of the size.
Making larger washers and spacers on the lathe, another method (-:
Begin with a rough cut disc, turn the jaws on a 4 Jaw for OD holding.
I place dowel pins in the jaws to get the part out for OD turning.
Face then turn the OD right up to the jaws then bore the ID, flip the part 180 Deg. and indicate the bore to zero, if the hole is large enough I indicate the back as well and knock it around until there is minimum run out, (place scrap aluminum or copper strips between the finished portion and the hard jaws).