On 02/17/2016 04:28 AM, Gregg Eshelman wrote: >> I'm now considering to take an old CD player and move the >> laser-assembly onto several micro-switches at different speeds. The >> laser-assembly is sub-micrometer accurate (CD track-separation runs at >> 1.5...1.6 um) and generally uses a simple stepper. > > They don't get that accuracy with the stepper. The lens is suspended on > springs and uses magnetic coils for fine positioning radially for > tracking and vertically to focus.
You are right. I was overly optimistic and too eager to use something on my desk. It is a darn difficult task to make something accurate. I did a wholy unscientific test on a no-name micro-switch with my calliper (0.01mm resolution) and was looking at about -0.01/+0.05mm variability. Most of that variability was most likely caused by me not holding the switch firmly enough. However, it does show that the activation of the switch is pretty consisent. It looks like a +/-0.01mm repeatability is readily in that switch (if not better), which again seems to align pretty well with other's experience. -- Greetings Bertho (disclaimers are disclaimed) ------------------------------------------------------------------------------ Site24x7 APM Insight: Get Deep Visibility into Application Performance APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month Monitor end-to-end web transactions and take corrective actions now Troubleshoot faster and improve end-user experience. Signup Now! http://pubads.g.doubleclick.net/gampad/clk?id=272487151&iu=/4140 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
