On Saturday 09 November 2019 21:44:20 Thomas D. Dean wrote: > I measured several rotations of the Z-axis lead screw on my Sherline > 4400 CNC lathe. > > The BACKLASH setting is 0.0035
Thats bordering on looking to see if it can be tightened up. Start by checking the screws end play. I've added reynolds wrap between the outer races of thrust bearing assemblies and their seats in the bearing housings in brand new screws. Might have to replace the balls with oversized balls, or figure out how to add ball thrust washers, I've done both. > > I started with a move in the + direction that was at least 2x the > backlash clearing I saw earlier. > > > G90 > > and then a sequence of 35 > > > G1 Z +0.0050 F6 > > reading the digital dial indicator after each move. > All the readings were within 0.0005, the limit of the dial indicator. > I can post the readings if anyone is interested. > The Z-axis lead screw does not seem to be a problem. > > Then, I measured the cut where I first noticed the backlash problem. > > > G90 > > dial indicator +0.5080 > > > G1 Z -0.530 F6 > > dial indicator -0.0215 move is 5300, 5080 plus 0215 equals 5295, you need to add the missing .0005 to your backlash=.0040 setting. > > G1 Z +0.530 F6 > > dial indicator +0.5080 > > > G1 Z -0.530 F6 > > dial indicator -0.0215 > > > G1 Z +0.530 F6 > > dial indicator +0.5080 > > Looks like the BACKLASH setting is good. > > I just need to remember to allow sufficient movement to clear the > backlash. > > Tom Dean > > > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users 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
