Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: joepardy on February 10, 2009, 11:31:41 AM

Title: G43 Sheetcam Problem
Post by: joepardy on February 10, 2009, 11:31:41 AM
I am experimenting with SheetCAM.  As part of its tool change routine, it inserts the following code:

N0220 (Process: Outside offset PARTLAYER, Mill/Router, 0.25 inch diameter, 4 inch Deep)
N0230 (Mill/Router, 0.25 inch diameter)
N0240 T2 M06  G43 H2
N0250 M03 S10000

The problem is with line N0240.  When the code appears as written, Mach does the following:
- Issues a tool change command - pausing the program requiring a Cycle Start
- Reads the offset from the tool table (in this case 4")
- Adds the offset to the Z Axis current coordinates
- MOVES the router up 4" (at the currently set feed rate)

IF however, you break apart the command into two lines:
N0240 T2 M06
G43 H2
then the Mach does the following:
- Issues a tool change command - pausing the program requiring a Cycle Start
- Reads the offset from the tool table (in this case 4")
- Adds the offset to the Z Axis current coordinates
- Router DOES NOT MOVE.

I believe that the SECOND action is what is suppose to happen.  It is my understanding that the T2 or G43 commands do not actually move the router/cutter.

Has anyone else experienced this problem?

I have also been able to duplicate this by typing the command
T2 M06  G43 H2
directly into the MDI screen, switching to the Program Run screen, acknowledging the tool change, and the z axis moves to ZERO at the currently set feed rate.

If I enter:
T2 M06
switch to the Program Run screen, acknowledge the tool change, return to MDI screen, enter:
G43 H2
directly into the MDI screen - and switch back to the Program Run screen .... the tool has changes, the offsets are changed, but the z axis remains at its current position (ie -4)


When the commands are issued on the same line
T2 M06  G43 H2
Mach appears to be issuing the following
T2 M06  G43 H2 G1 Z0

It is the "G1" move that is driving me nuts.

Help!   ???

Title: Re: G43 Sheetcam Problem
Post by: HimyKabibble on February 10, 2009, 12:16:14 PM
My guess would be you need to modify the m6End macro to remove the move to 0.

Regards,
Ray L.
Title: Re: G43 Sheetcam Problem
Post by: Hood on February 10, 2009, 01:41:56 PM
Have a look at your safe Z settings, it may have something to do with it.
Hood
Title: Re: G43 Sheetcam Problem
Post by: joepardy on February 10, 2009, 03:23:00 PM
Hood,

I did look at the Safe Z settings.   This is what I found:

Allow Safe Z Moves is checked
Machine Coordinates is checked
Safe Z is set to 0 (on my machine, this is full up)

I tested all the options.  Safe Z CHECKED, Machine Coordinates OR Work Coordinates OR Incremental checked - Have the problem with the z axis moving.

WIth Safe Z UNCHECKED, no problem with z axis moving during this command.

I am not sure why this should be happening.  It seams to me that Safe Z set to 0 means that the axis will move until the Z DRO is Zero.   What I am finding is that before the move (assuming that safe z is checked), Machine Coordinates are 10.5 and the Work Coordinates are 0.0.  After the "safe" move, Machine Coordinates is 14.5 and the Work Coordinates is 4.0.

Are the settings for safe z moves typically used?
Title: Re: G43 Sheetcam Problem
Post by: Hood on February 10, 2009, 03:29:52 PM
I think its the way the M6 End is written, its dependant on what you have the safe Z set to and in which units. If I remember correctly you can just edit out the safe Z move in the macro and your problem will go but as I have never suffered from it I cant recall properly. If you do edit make sure you are ready on the E-Stop in case things dont go as planned.

 Hood