by lasersafe1 » Mon Dec 20, 2010 5:14 pm
We are concerned about microns with lasers, so I would go with an optical knife switch. Perhaps you have had good experience with mechanical, but the repeatability specs are not as tight.
Oops... just noticed you are talking about the cover interlock. Yes, this is nice but it still doesn't meet 21CFR1040.1 if you wanted to call this a commercial class build (even though I know your intent is to forever remain open source). In order to meet this spec, you need to have a limit switch that is not easily overridden and when overridden the cover cannot close properly. The "not easily overriden" part is usually interpreted to mean that you need a tool to install and remove the override.