Alignment disks, and the creation thereof

But, we're drifting off-topic again. The question is really "Can a hobbyist, with modern technology, build a device to write new alignmnent disks?". I definitely think so. Such a device would definitely be a mix of new and old parts. I mean, why reinvent the disk drive? The basic disk motor, heads, frame, etc. should be fine. The only thing I think that could use an upgrade would be the positioner. Voice coil positioning isn't really what we want here. The only thing we care about is precision, not speed. A stepper would work, just maybe one that's more precise than the one in the drive - or perhaps one that's gear reduced. A leadscrew based drive might be a good candidate, with some kind of precision servo on it. It doesn't matter how fast it is, just as long as it's accurate. Who cares if it takes ten minutes to write an alignment disk?