On Tuesday 08 August 2017 21:52:35 Jon Elson wrote: > On 08/08/2017 08:42 PM, Dan Bloomquist wrote: > > I have not set homing up on my mill yet, I've been mulling > > it over. A switch is not satisfying unless there is a way > > to keep from hunting for it, can't imagine... > > If you have encoders with index, that can set the home > position to an exact encoder count, there's no sense > in resolving finer than that. This allows you to align the > work coordinates one day, shut down and then come back the > next day and home the machine, and have as accurate an > alignment to the part or fixture as the previous day. > > > So it occurred to me to us a laser range finder. Then lcnc > > would know where the table is without having to move on > > boot. It does not have to be accurate like to mm as I > > probably never have to mill to the limit switches, and > > even then.... > > > > So I started to look around out there, this is amazing for > > the price: > > <http://www.ebay.com/itm/VL53L0X-Time-of-Flight-Distance-Sensor-Brea > >kout-GY-VL53L0XV2-Module-for-Arduino-/201718280643> > > 10% of range guaranteed? Hmmm, I am NOT impressed by the > specs. So, from a foot away, they guarantee you can resolve > an inch! The mirror would eventually get dirty and result > in reduced accuracy, too. > > Jon > 10%? Not at all usefull. That sort of accuracy will cost one broken tooling at >$20 a copy. I'm using ebay sourced microswitches at about a buck a copy. Doesn't sound like much, but on a dry circuit, which the homeing circuits are, milliamp or so, I seem to be able to get .001" repeatable accuracy. Some might not think thats good, but its certainly close enough for the stuff I do. And in 3 years, I have had no failures. Zero.
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Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> ------------------------------------------------------------------------------ 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 Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
