On my lathe I only touch off to fixture the Z axis and use the spindle face as my fixture. X is always touched off to the material in the tool table. I don't use the touch off buttons because I've added some PyVCP buttons to do the touch offs.
Touch off to spindle face MDI_COMMAND = G10 L11 P#5400 Z0.0 Update the tool offset for chicken checks MDI_COMMAND = G43 Touch off Z to the material face with a 3/8" dowel MDI_COMMAND = G10 L20 P1 Z0.375 My basic procedure is to touch off Z to the spindle then if it makes sense for that tool cut and measure the od and touch off to the tool table that diameter. For drills I use an indicator to center the drill chuck and make that X0. JT On 6/24/2015 11:06 PM, Tom Easterday wrote: > For tool and work offsets on my mill I follow the advice given here: > http://wiki.linuxcnc.org/cgi-bin/wiki.pl?MillSetup > <http://wiki.linuxcnc.org/cgi-bin/wiki.pl?MillSetup> which in a nutshell > says: you set one tool (an edge finder perhaps) at a specific point and then > reference all tools (in length, ie. Z) to that reference tool. So settings > in my mill tool table have Z values that are +/- the difference in length > between the reference tool and the given tool. > > I am trying to set up the tool table for a lathe and am having problems. I > see that the advice for doing this differs from what I am doing above on my > mill. So, I was trying to follow the advice in section 21.4 of the Linuxcnc > User Manual: http://www.linuxcnc.org/docs/2.7/pdf/LinuxCNC_User_Manual.pdf > <http://www.linuxcnc.org/docs/2.7/pdf/LinuxCNC_User_Manual.pdf> > > I have the Z offsets in the tool table and that part seems to be working. > However, I am having problems getting the X offsets to work (even though i > think i am doing exactly the same thing as Z). I set the X offset by doing > this: > > In MDI issue: T1 M6 G43 > Turned down some stock to 0.55” > Select “Touch off to fixture” in Machine menu > Make sure X is the selected radio button > Select “Touch off Tool” button (This button is new in Axis in 2.7 I think?) > (Bug? in 2.7.0~pre6 - the dialog for this button refers to Workpiece not > Fixture) > Enter 0.275 (yes, I entered a positive number even though my tool is above > the spindle centerline - is that correct?) > > In the tool table I get an X value that basically looks like a distance from > G53 X0 (something like 1.XXXX). > > Then to enter a second tool: > In MDI issue: T8 M6 G43 (This is a 0.25” drill) > Bring it down to touch the top of a 0.100” pin which is on top of my 0.55” > workpiece > Select “Touch off to fixture” in Machine menu > Make sure X is the selected radio button > Select “Touch off Tool” button > Enter 0.275 + 0.100 + 0.125 = 0.5 (yes, I entered a positive number even > though my tool is above the spindle centerline - is that correct?) > > In the tool table, again, I get an X value that basically looks like a > distance from G53 X0. > > When I go back to tool T1 (T1 M6 G43) and then issue a G0 X0 the tool goes to > the center of the spindle as it should. > > But, if I return to tool T8 (T8 M6 G43) and issue a G0 X0 the drill does not > go to the center of the spindle. And it’s distance away is not any of the > measurements above, in other words I can’t figure out where I went wrong. > > Perhaps I should just be following the procedure I used on the mill and just > forget about “Touch off to fixture” and “Touch off Tool” and enter values +/- > of the reference tool? > > I am quite confused at this point. I have looked at JT’s tutorials, and all > the Linuxcnc manuals and other random documents that talk about this, but > every time I think I understand and try the procedure I get the wrong result. > By the way, I have entered the ORIENTATION and the FRONT and BACK ANGLES in > the tool table for these tools, could those things (if I happened to enter > them incorrectly) effect the X offset? > > -Tom > > > ------------------------------------------------------------------------------ > Monitor 25 network devices or servers for free with OpManager! > OpManager is web-based network management software that monitors > network devices and physical & virtual servers, alerts via email & sms > for fault. Monitor 25 devices for free with no restriction. Download now > http://ad.doubleclick.net/ddm/clk/292181274;119417398;o > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users ------------------------------------------------------------------------------ Monitor 25 network devices or servers for free with OpManager! OpManager is web-based network management software that monitors network devices and physical & virtual servers, alerts via email & sms for fault. Monitor 25 devices for free with no restriction. Download now http://ad.doubleclick.net/ddm/clk/292181274;119417398;o _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
