Gentlemen, On my bridge mill 5 axis Fanuc 15mb XYZ linear axes BC head with the B axis riding on the C axis - picture of same but newer machine http://mightyusa.com/b-5000%205bc.html
Absolute encoders on all axes C axis has slip rings - there is no need to unwind while cutting - the axis can rotate 'infinitely' notice the quotes around infinitely as the control allows 9,999.999 degrees of encoder count XYZB cannot exceed the encoder count because of physical limits C has unlimited physical motion capability - the control has limited motion capability I would think the newer control has larger registers but I do not know this as fact. I had to size a large hole through a large punch press connecting rod. The head barely fit into the hole and the part was tall enough I had to rotate the B axis up to allow clearance to position the head over the hole. With a ball nose end mill in the spindle I set the diameter by rotating the B axis and bored the hole by rotating the C axis. First pass roughing I rotated the C axis 1 revolution, moved Z down and rotated C again. Repeating for every pass with a loop I was surprised the machine stopped after just a few passes. C axis machine position was 9,999.999 degrees. I changed the program to reset the C to zero for every pass. Surely this would allow the program to finish. Not so, the machine stopped in exactly the same spot. I was able to cut the part by changing the program to rotate one direction, move down, rotate the opposite direction, move down, then loop the program. This worked just fine but it shows fanuc controls handle the axis motion in the same manner as LinuxCNC. I would guess all controls would handle the axis motion in the same manner. I have no experience with a lathe that the spindle is also a C axis. thanks Stuart On Tue, Jan 5, 2016 at 5:34 AM, Dave Caroline <dave.thearchiv...@gmail.com> wrote: > Here is an example of with and without limits in a trunnion design > > http://www.ebay.co.uk/itm/CNC-Rotary-Table-Dividing-Head-Rotational-Axis-4th-5th-Axis-A-B-Axis-100MM-Chuck-/161679996211 > > Dave > > On 05/01/2016, andy pugh <bodge...@gmail.com> wrote: > > On 5 January 2016 at 04:37, Cecil Thomas <wctho...@chartertn.net> wrote: > >> By the way if there have been any changes in LCNC that let you "home" > >> or set the rotary axis back to zero without exiting the program or > >> actually running the axis back to zero I'd like to know about it > >> since I haven't looked into it for over 10 years. > > > > Re-homing the rotary would reset the absolute position. > > There are HAL pins to home each axis. (halui.joint.N.home bit in) > > You can drive a bit pin from G-code. > > So I think it could be done, but it seems like a kludge. > > > > -- > > atp > > If you can't fix it, you don't own it. > > http://www.ifixit.com/Manifesto > > > > > ------------------------------------------------------------------------------ > > _______________________________________________ > > Emc-users mailing list > > Emc-users@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > > > ------------------------------------------------------------------------------ > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > -- Addressee is the intended audience. If you are not the addressee then my consent is not given for you to read this email furthermore it is my wish you would close this without saving or reading, and cease and desist from saving or opening my private correspondence. Thank you for honoring my wish. ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
