On Tuesday 14 July 2020 06:38:57 Ed wrote: > On 7/13/20 11:09 PM, Chris Morley wrote: > > There _is_ only one home position. But it doesn't need to be at the > > origin or switch trip point. The problem seems to come from people > > thinking the contact with the homing switch is where home is. which > > is not surprising, as when you ask linuxcnc to home that's where it > > goes first. But it's where the machine stops _after_ homing that is > > actually home and it doesn't have to be the origin. > > > > You can of course set it up as you described, but that is only one > > of a million different ways. Here the two switch exmple show home at > > the origin and home at 3: > > http://linuxcnc.org/docs/2.8/html/config/ini-homing.html > > > > I might point out this is machine coordinates which most people > > don't normally work in. > > > > As I said homing is actually complicated - through linuxcnc's > > flexibility. > > > > Chris > > To illustrate what Chris is saying. On my Hardinge CHNC lathe the X > cross slide home switch activates when the slide is in the full > positive position. The minor problem to this is all tool offsets are > negative from that point. By changing the .ini file "HOME_OFFSET=0" to > "HOME_OFFSET=4.5" the machine goes to the home switch, activates, then > moves 4.5 (lathes set up in radius) and calls that home. This gives > me tool offsets with positive numbers on the X axis, much easier when > fine tuning the last couple of tenths.
I am doing a similar thing with the 11x56 Sheldon, except I've a relatively large QCTP on a fixed base, no compound because LinuxCNC drives the cross slide to give the effect of the compound. Without the compound, its considerably more rigid. BUT with a BXA wedgeing toolpost, and the outer limit set a bit more restricted than OEM. My offset is a hair under 4". I can still reach stuff hanging outside of an 8" chuck by turning the tool post around and mounting the tools on the back side of the post, just did it this past week makeing a nema-23 motor mount out of the end of a 3.5 by 8" piece of half inch alu. I'm motorizing a BS-1 clone. That will make my 3rd motorized A axis for my milling machines. Had to buy a hoist, by the time its finished its right at 200lbs. I shoulda started with a BS-0... > > Ed. > > > > > _______________________________________________ > Emc-developers mailing list > Emc-developers@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-developers 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-developers mailing list Emc-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-developers
