Most of the machines I configure, I normally set them up to park close to the home switch, so that search times are relatively short. And on the occasion that it isn't, it is usually no big deal to manually jog the machine close before beginning the homing sequence. It is also why the homing sequence has two speeds. With the right switch configuration, the machine should be able to search out the home switch at it's fastest speed, then use the latch velocity to precisely locate the home position (either using the switch or the index pulse of the encoder.)
----- Original Message ----- From: "Chris Albertson" <[email protected]> To: "Enhanced Machine Controller (EMC)" <[email protected]> Sent: Wednesday, August 9, 2017 1:07:43 PM Subject: Re: [Emc-users] Using laser time of flight sensor to home mill One use I can think of for a low precision sensor is that you should be able to home faster. The motor can run at full speed until it gets close then slow just before it hits a mechanical switch. For this use case 10% error is good enough. On Wed, Aug 9, 2017 at 9:40 AM, Stuart Stevenson <[email protected]> wrote: > Hi, > > Positioning the laser with magnets seems like an invitation to disaster. > The laser WILL get bumped or jiggled out of position. Hopefully, the out of > position would result in the machine not moving instead of moving to the > wrong position. > > Using the laser to establish rough position (therefore eliminating the > need for a limit switch) to allow homing from the startup position seems > "reasonable" if you can determine the laser position is repeatable enough > to catch the encoder index mark on the correct rotation. > > To me, if you plan to home the machine, this sounds like a solution in > search of a problem although I don't know the complexity of installing > limit switches. > > thanks > Stuart > ------------------------------------------------------------ > ------------------ > Check out the vibrant tech community on one of the world's most > engaging tech sites, Slashdot.org! http://sdm.link/slashdot > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users > -- Chris Albertson Redondo Beach, California ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
