On 16 February 2016 at 14:46, Bertho Stultiens <ber...@vagrearg.org> wrote:
> On 02/16/2016 01:38 PM, Nicklas Karlsson wrote: > >>>> It seems that the micro-switches are well suited for the purpose, but > I > >>>> guess some hard (unbiased) data has yet to be gathered (outside of a > mill). > >>> The alternatives seem to have the same problems of repeatability. Using > >>> a hall sensor or optical one will give the same problems. > Micro-switches > >>> are at least inherently mechanically constrained. > >> Indeed, unless you can crush them. There must be a run-into-the-wall > >> protection, as mentioned earlier, to prevent killing your switch. > > > > Pass over the switch might be possible? > > No. The datasheets I've read all say the same that you must activate the > plunger straigt on. Any angle will give you bad performance. Any > sideways stress on the plunger can kill the plunger assembly. > > The only alternative is to use a level-based micro-switch. That, > however, will probably make it less accurate. Especially when you move > over it side-ways. The angle of attack is too small with respect to the > travel distance. > > -- > Greetings Bertho > > > That's not true. Use a switch like this <http://uk.rs-online.com/web/p/microswitches/1031645/?searchTerm=103-1645&relevancy-data=636F3D3126696E3D4931384E525353746F636B4E756D6265724D504E266C753D656E266D6D3D6D61746368616C6C26706D3D5E5C647B337D5B5C732D2F255C2E2C5D5C647B332C347D2426706F3D313426736E3D592673743D52535F53544F434B5F4E554D4245522677633D4E4F4E45267573743D3130332D3136343526>, where the roller is almost directly over the plunger. Then, use a wiper with an edge set at about 70deg. When this approaches the switch, the angled edge will cause full travel over less than 1mm. After that, overtravel will have no effect. I've never seen a travel limit switch used head-on in a machine. It's a ticket to disaster. Regards Roland ------------------------------------------------------------------------------ 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
