Mpmaster 4-axis substitution

[bbrown01]

I'm having a problem while posting with mpmaster (vmc) for axis substitution for a rotary toolpath. I'm trying to drill 4 blind holes (90° apart) on a cylinder following a tutorial in the 4/5 axis milling guide by In-House.

 

Instead of starting at 0° the mpmaster post (gcode below) a-axis starts at 180° then 270°, 360°, 450°. The generic fanuc 4-axis post outputs 0°, 90°, 180°, 270° which is what I would expect.

 

I'm using TOP for my WCS/T/P so I think I'm using the proper "reference view" as describe in the post text. I've played with all the a-axis/rotary parameters I could find in the machine and control definitions. On 7/27/07 there was an "updated mpmaster" comment from Brett Thomas about "Next project is to clean up axis substitution with respect to start points being close to (within 180 deg) the ends of previous chains/paths". Is this related to what I'm seeing?

 

I would like to standardize on mpmaster for both 3 and 4-axis programs.

 

Mpmaster vertical:

 

%

O0001 (OP-1)

(MPMASTER GENERIC 3/4-AXIS VERTICAL)

(MACHINE GROUP-1)

(MASTERCAM - X)

(MCX FILE - C:DOCUMENTS AND SETTINGSBBROWNDESKTOPROTARY.MCX)

(POST - MPMASTER)

(MATERIAL - ALUMINUM INCH - 2024)

(PROGRAM - OP-1.NC)

(DATE - DEC-09-2007)

(TIME - 5:14 PM)

(POST DEV - IN-HOUSE SOLUTIONS)

(T1 - 3/8 DRILL - H1 - D1 - D0.3750")

N100 G00 G17 G20 G40 G80 G90

N110 G91 G28 Z0.

N120 (DRILL - AXIS SUBSTITUTION)

N130 (TOOLPLANE NAME - TOP)

N140 T1 M06 ( 3/8 DRILL)

N150 G00 G17 G90 G54 A180. X7. Y0. S713 M03

N160 G43 H1 Z4.

N170 G94

N180 G98 G81 Z1. R2.1 F4.22

N190 A270.

N200 A360.

N210 A450.

N220 G80

N230 M05

N240 G91 G28 Z0.

N250 G28 X0. Y0. A0.

N260 G90

N270 M30

%

 

Fanuc 4-axis:

 

%

O0001(OP-1)

(DATE=DD-MM-YY - 09-12-07 TIME=HH:MM - 17:17)

(MCX FILE - C:DOCUMENTS AND SETTINGSBBROWNDESKTOPROTARY.MCX)

(NC FILE - C:MCAMXMILLNCOP-1.NC)

(MATERIAL - ALUMINUM INCH - 2024)

( T1 | 3/8 DRILL | H1 )

N100 G20

N102 G0 G17 G40 G49 G80 G90

( 4 - AXIS VMC )

( MACHINE GROUP-1 )

( DRILL - AXIS SUBSTITUTION )

N104 T1 M6

N106 G0 G90 G54 X7. Y0. A0. S713 M3

N108 G43 H1 Z4.

N110 G98 G81 Z1. R2.1 F4.22

N112 A90.

N114 A180.

N116 A270.

N118 G80

N120 M5

N122 G91 G28 Z0.

N124 G28 X0. Y0. A0.

N126 M30

%

 

---------

X2 MR2 Mill L3

Solids

[Dan@home]

If your just trying to drill the 4 holes. Don't use axis substitution. Uncheck Rotary axis button. Leave WCS on the top. Drill each hole (separate), changing your Cplane & Tplane to top, front, named view ext. for each hole. It should post correct. Solid drill may work also.

[Kannon]

or do a transform-by toolplane

[Storkman]

Set the post to limit the 4th axis to one revolution.

[bbrown01]

Thanks for the responses.

 

danbo, Kannon - this is just a test, the real part I plan to drill, slot and engrave using axis subsitution.

 

Storkman - I'm assuming you mean limit the a-axis travel in the machine definition to 360°? If I do that I get a post error when it gets to 450°.

 

Playing with this a little more I have been able to get the expected output from mpmaster by changing the rotary axis in the toolpath to cw and the direction of rotation to ccw in the a-axis machine definition. But it doesn't make sense.

 

Here is a z2g file if anyone has interest to take a closer look.

 

http://www.santacruzoptics.com/tmp/ROTARY.Z2G

 

Thanks again.