On 02/16/2016 02:01 PM, Lester Caine wrote: >> Indeed, unless you can crush them. There must be a run-into-the-wall >> protection, as mentioned earlier, to prevent killing your switch. > > The problem on the Taig is while one hits the end stop one end, you come > out of the nut the other ;) But while stalling the motors looses > position, it's not a particular problem from the safety point of view. > Unless you put a finger in the way ...
The router here is constrained at both ends, so that would be fine. Stalling will be an issue. Regarding fingers, well, I'm not sure about some of the would-be operators ;-) We do have a sign stating "KillBot Machine" and other large graphic and descriptive words of how you will die when mismanaging the machine. > I've been looking to fit slotted sensors as limit switches to prevent > problems at both ends of the table, with a flag on the bed which goes > through the sensor (so no crush problem), and this is fine for limiting > things, but it's repeatability is somewhat suspect for use as a home > position. I was seeing 0.1mm drift depending on various factors, but not > being desperate for it I did not investigate further. Optical sensors are problematic for repeatability unless you have very good ones (like encoders). That said, general accuracy of 0.1mm would be sufficient for most of the things done on the machine (simple woodwork). The machine itself is rated at 0.02mm repositioning, so a 0.01mm homing repeatability is more than enough. The micro-switches look like they can manage at almost no cost. But then my curiosity got in my way on how far you actually can go with the cheapo method. 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. -- 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
