On Sunday 14 July 2019 09:46:02 andy pugh wrote: > On Sun, 14 Jul 2019 at 14:43, Roland Jollivet > <roland.jolli...@gmail.com> > > wrote: > > Jogging up is better, backlash notwithstanding. > > Use an accurate rod or the shank of an endmill, say 10mm > > Jog upwards while you gently try to roll the rod under the cutter > > Yes, I should have perhaps gone in to more detail of the touch-off. > The way you describe is what I do when I want accuracy, I use some of > my massive stock of broken end-mills as the reference. > > But for a skim cut to start a job, especually with the big shell mill, > I often simply jog down until it starts to cut, and call that my > surface (it soon will be)
Another technique I've used, works well on the G0704 as its spindle is well grounded, and when making a "box" of parts, is to plant a small bit of pcb at some fixed and findable point on the jigging with super glue, and run the machine to above it. The top of the pcb is connected to the probe input, I start the spindle in reverse so the contact is not destructive either to the copper or the tool, go down to the probe trip, then back upwards at about 10% of the down speed until the probe opens. This point is recorded as the #<_tlo>, and that becomes z=0 for the rest of the time that tool is in use. Unforch I've got to figure out a better way on the 6040 as theres no way, with all the epoxy paint, and apparently ceramic bearings in the spindle motor to assure a good ground on the tool. So I've both a spindle mount probe and a contact pad/switch. Now my problem is a solid mount for it... Due to the wires stiffness, and its low weight it cannot be convinced to lay dead flat on the table. Combine that with the lack of a grounded tool needing to have a ground clipped onto the tool and a PITA is what it is ATM. But I'll figure out something. Just saying there's more than one way to skin this cat. 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 Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
