In developing an Okuma MillAC 1000VH post (B-head in ZX-Plane) (C-Table in X-Y plane), the user wants to set-up his zero on the part (not at center of Table). Upon using MAIN MCS (center of table) and a Local (of all choices) at the corner of a part, none of the Local outputs seem to output the C-axis, except the USE MAIN option. However, this mode outputs as designed-- from the center of table. The coordinates of XYZ (with B and C head/rotary), will need to be adjusted by values in the event MOM_csys. Further, an example I have for 5-Axis contouring ona Okuma MillAC800VH- the post uses direct MCS GOTO'S for X Y Z , in G169 TCM mode. Any comment welcome.
There are three distinct methods of outputting 5 axis motion in NX.
The main mcs is placed at the center of rotation of the most dependent axis. The MCS type is Use Main. The X Y Z B C is all relative to main. The ORIGIN command may be used as a constant offset.
2) Local or CSYS_ROT
A local MSYS is placed at any convenient location. All output is now relative to this local msys. However, there must be a coordinate mapping function like G54, G68.1, CYCLE800, PLANE SPATIAL, to map the coordinates to the main msys on the machine. When using a local csys all output including C axis is relative the local csys. The mom variable init_pos can be used
3) TCP (Tool center point)
The post outputs tool tip locations. This is the msc_goto in nx and is essentially cl file gotos. Depending on the controller this is G43.4 (Fanuc), TRAORI (Siemens), M128 (Heidenhain),