I am running a vm16 that dosnt like tools to be left in the spindle at program end.I try to load the first tool needed ind the program at program end to save startup time. If I start up with a tool in the spindle the Z axis goes positive agenst the limit switch. The program end is written as follows:
N9900 (program end)
M05 : spindle off
G00 X2.600 Y2.000 : Begining spot
T12 M06 : Select 3/16 end mill & its length of offset
D12 G43 H12 : set nose dia. & length of offset
M30 (end of program)

What does the beginning of the program look like? Todd

are you programming in conversational or g code?
The Farmer

I have the VM/16 back up and running but still wonder why it was having a fit.
The program was blocked stepped up to the point of the problem but it makes no sense. The program reads as follows: N2000
G00 X2.600Y2.00
T12 M06
D12 G43 H12
M08
S2200 M03

The failure was at G00 X2.600Y2.00 .When this line was moved down past the tool change the problem went away. also if the tool change was removed from the last program block there was no problem. Why would an X,Y or tool change affect the Z axis ? Thanks for the help

It sounds like a flag is set when the "H" command is executed. Then when the next G00/G01/G02/G03 command is executed and the flag is set, the previous offset is completely incorporated. End the program before a move command is executed and the flag is cleared. This leaves the controller in a strange state.

At least you found a work around.