IC profiler

[Chuck(G)]

I should also mention that when we were rolling our own alignment floppies, we used a Micropolis drive with the precision leadscrew mechanism. Micropolis was very proud of that one--4 steps IIRC per cylinder. They tried to retain it well into the time when everyone else was using taut-band mechanisms, but price-wise and speed-wise, they couldn't compete.
By way of comparison, CD and DVD drives are far more sophisticated mechanically than their floppy counterparts.

 

[Selectric]

The 100tpi Micropolis drives are amazing beasts. I restored two recently - a 1043 Mod I and a 1053 Mod II. Troubleshooting the drive boards was part of the process but the most rewarding part was cleaning and lubing the lead screws. They sparkle and look a million bucks in action (they look like machined/turned stainless steel - is that a thing?) Spot on with the 4 steps per track: that's what the manual says, and from what I've seen, that looks like that's what they do.

 

[Chuck(G)]

One of the reasons that Micropolis dropped out of the floppy business was that they couldn't compete on price. One of their last attempts was the 1115--I've got one. Still uses the leadscrew-type positioner, but a zamak cast body, unlike earlier drives, which were galvanized steel plate. Even so, back in the day, the OEM price for one of these was close to $600 USD. With the cheap drives from the likes of Tandon, competition was impossible. On the last of our systems, we were using MPI drives because Micropolis couldn't compete.