Momemade Alignment disk

On Mon, 27 Jan 2014, Tony Duell wrote: I think that you could modify the stepper mechanism on some drives to add a calibrated offset - a simple verneir scale, or a micrometer head to alter the radial position by known small amounts. Then, although you would NOT have sectors offset relative to each other within a track, you COULD write disk(s) with each track at a different offset from its nominal position. Software would then need to look at which TRACKS could be read, instead of looking at which sectors within a track. If it is more desirable to go with the offset hub, (and have sectors differ in offset from each other within a track), . . . either machine an entire replacement hub assembly, with the spindle mount slightly off-center (surely the amount of offset required would not be enough to run into serious difficulties with the off-axis load? and rebalancing the off-center flywheel would not be that much different from what we used to do to balance rotating automotive parts.) Rather than machining an entire assembly, could you not bore out the spindle hole in the hub and make a bushing? And then, replace that bushing with a bushing with ID/OD not quite coaxial? (As you can see, my maching abilities vary between non-existent and incompetent amateur) It seems to me that an ANALOG alignment disk would require special heads, and even the digital alignment diskette might be improved upon with some slightly different heads. For example, using a 96tpi head for creating a 48tpi alignment diskette might make it easier to detect misalignment. And custom heads, . . . ? -- Grumpy Ol' Fred cisin at xenosoft.com http://www.xenosoft.com/FPUIB