I have a friend who is an engineer who sets up laser trackers on those big mills all over the US. The only way you can maintain .005 tolerances over 50 or 60 feet on a big gantry machine is with a laser tracker. They do coordinate compensation on the fly. Siemens has a plug in interface that they use to do that.
That 100 foot long mill is the biggest one I have heard of. Most of the big ones are used for military contract work. There was a big one for sale on Ebay last year - still erected. I think it was 50 feet long. It never sold on Ebay. Dave On 2/29/2012 4:39 AM, Roland Jollivet wrote: > On 29 February 2012 10:56, Dave<[email protected]> wrote: > > >> There is a lot of BS on that webpage. Optical encoder accuracy.. >> Impressive to those who don't know better I guess. >> >> This is really the only important fact regarding accuracy: >> >>We use Leica laser trackers to measure the volumetric Cartesian >> errors. These devices have accuracies of approximately 0.002 inches (51 >> microns) in our working envelope. >> >> Those are required to get any decent accuracy on a machine that large. >> That machine probably grows and shrinks a quarter of an inch or more >> with temperature swings. >> >> Dave >> >>> >> > > What temperature swing? 0.2deg ? Temp control is cheap. > > Regards > Roland > ------------------------------------------------------------------------------ > Virtualization& Cloud Management Using Capacity Planning > Cloud computing makes use of virtualization - but cloud computing > also focuses on allowing computing to be delivered as a service. > http://www.accelacomm.com/jaw/sfnl/114/51521223/ > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users > > ------------------------------------------------------------------------------ Virtualization & Cloud Management Using Capacity Planning Cloud computing makes use of virtualization - but cloud computing also focuses on allowing computing to be delivered as a service. http://www.accelacomm.com/jaw/sfnl/114/51521223/ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
