10 Feb
2009
10 Feb
'09
2:51 p.m.
Philip Pemberton wrote:
A voice-coil actuator /might/ be more accurate than a
stepper, but you
still need a servo system to align it. Ladies and gentlemen, meet
catch-22: you want to write the servo tracks, but you need the servo
tracks to write the servo tracks...
I've seen photos of a gadget that was built to re-write servo tracks
on hard drives. It was set up in a clean room (of course) in the
early 1990s, with interchangeable modules for different makes/models
of drive. They were real, non-digital photos on 10x8 glossy paper!
Will ask about them again, and see if they can be scanned. The guy
who built it was an ex-UK101 user who I met at the local Linux
User Group.
--
John Honniball
coredump at gifford.co.uk