On Thursday 25 June 2015 06:42:55 John Thornton wrote: > 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
How to do that reliably when the drill is toolpost mounted has so far escaped me John. But on my toy, I find the toolpost mounted drill is far handier than the tailstock usage. My tailstock is a far far cry from spindle aligned. Sideways (x offset) I can adjust, clumsily, but up and down (call it y) is several degrees off axis and would need more cast iron added to the castings to correct. So I put a small center drill in the chuck, hope it is sufficiently aligned axially since the toolpost doesn't have a 90 degree lockdown pin, then bring the drill to the face and diddle both x and y(toolpost locking height) until it is well centered, then finish the pilot hole. Change to a drill bit, discover the toolpost is a degree out of alignment & turn it till the drill is aligned, then drill the starter hole for the boring job. Needlessly complex, but works as long as the drill is sharp enough that its backthrust doesn't cause the toolpost to slip. Drill Doctor demanded to achieve that reliably. A tut on how you do it, on your web site, would get read and re-read by this user. > 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 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) Genes Web page <http://geneslinuxbox.net:6309/gene> ------------------------------------------------------------------------------ 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
