On Saturday 18 January 2020 23:48:59 Jon Elson wrote: > On 01/18/2020 01:14 PM, andrew beck wrote: > > Hi guys > > > > I was just wondering who here has retrofitted any big commercial > > machines with linuxcnc and who actually uses there machine to make > > parts everyday. I work in machine shops and am using fagor/ siemens/ > > controllers all the time. and I am retrofitting a cnc mill myself > > as a project and so I can start my own machine shop at home on the > > farm. > > Stuart Stevenson made these videos when he was previously at > MPM in Wichita, KS. > > https://www.youtube.com/watch?v=mxxdq6y8z8M > > https://www.youtube.com/watch?v=Nn1bJ3YAQdI > > https://www.youtube.com/watch?v=35tHYaDUmZQ > > He had 2 GIANT Cincinnatti 5-axis mills there, one > previously retrofitted with OpenCNC, and this > one with LinuxCNC. He built a 5-axis error compensation > matrix to correct motion alignment errors > in the machine, and added this to the LinuxCNC code. The > demo with the 3 indicators on the big ball > shows that the errors are well compensated while all 5 axes > are in motion. > > MPM also had a colossal Giddings and Lewis horizontal boring > mill, also run by LinuxCNC. > > He later left MPM and set up his own shop where he has a > couple more of the 5-axis Cincis, and a bunch > of other machines. > > I don't make parts every day, but most of the work on my > Bridgeport is for commercial production. > But, since I am the only guy here, I have to do all the > other work as well. > > I'm helping a local guy retrofit a Hardinge CHNC I lathe > which will go into commercial production when > we get it finished. > > Jon > But, fancy comp schemes aren't limited to the huge stuffs. On my Sheldon 11x56, I have used that lincurve code to compensate for bed wear of that 70 yo machine. I can now go from just clearing the chuck to the tailstock with a max OD variation of +- .0015". I could get closer but the lincurve module only has 16 correction points. I've conjured up a way to use 2 to get even closer, but haven't actually implemented it yet. All done by an r-pi4b. But because the left Z screw covering bellows is being compressed enough to affect the carriages seating on the v-way, I need to add tapered gibs to hold it down better before the finer grained lincurve is worth implementing. That and write an automatic calibrator based on the bore sighting laser setup I've used to calibrate it by hand. IMO, extreme accuracy can be obtained from any machine rigid enough to hold those settings.
That to me is the beauty of linuxcnc, you can make it do anything you want it to. If you can measure the error, you can compensate for it. I don't have an interferometer so no way to detect longitudinal screw errors in C7 grade screws. But if I did have that tool, I could correct that too. In watching the Cinci 5 axis move, the impressive thing to me is how slow it moves. 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) If we desire respect for the law, we must first make the law respectable. - Louis D. Brandeis Genes Web page <http://geneslinuxbox.net:6309/gene> _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
