In a program z-axe start at a save position, then going to Z-0.2.  After this G01 movement in X- and Y-axis.
After a while Z-axe is going minus, but it is not programmed. Z-axe keeps on going down 

Hi Stef

What ver. Mach3, Post your code, Someone will look at it.

Thanks, Chip

Hi Chip,

We are working with mach2
We work on the machine with step-direction steppermotor without encoders.

Stef

Hello,

The problem above, is the problem with my machine.
The z-axe is going down faster and faster in the matertial, until, ...

Sometimes its works perfect, and sometimes its going wrong.
I have no idea whats happend.

This is my code:
G21
G0 G17 G40 G49 G80 G90
G61(CONSTANT CONTOUR OFF OR TURN ON W/G64)
M07(Cooling ON)
(2 1/2 Axis Pocketing)
G55
S1000 M03
G00 Z1.5000
X0.0000 Y-2.2500
G01 Z-0.6000 F30.0
Y0.0000 F50.0
X130.0000
Y-3.0000
X0.0000
Y-2.2500
X0.7500
Y-0.7500
X129.2500
Y-2.2500
X0.7500
G00 Z1.5000
X0.0000
G01 Z-1.2000 F30.0
Y0.0000 F50.0
X130.0000
Y-3.0000
X0.0000
Y-2.2500
X0.7500
Y-0.7500
X129.2500
Y-2.2500
X0.7500
G00 Z1.5000
M05
M30

I hope that someone can help my, it's verry urgent.

Thanks a lot.

Hein

Hi, Hein

Try this.

G21
G17 G40 G49 G80 G90 ;-----------------------------------------Removed the G0 in this line of Code
G61(CONSTANT CONTOUR OFF OR TURN ON W/G64)
M07(Cooling ON)
(2 1/2 Axis Pocketing)
G55
S1000 M03
G00 Z1.5000
X0.0000 Y-2.2500
G01 Z-0.6000 F30.0
Y0.0000 F50.0
X130.0000
Y-3.0000
X0.0000
Y-2.2500
X0.7500
Y-0.7500
X129.2500
Y-2.2500
X0.7500
G00 Z1.5000
X0.0000
G01 Z-1.2000 F30.0
Y0.0000 F50.0
X130.0000
Y-3.0000
X0.0000
Y-2.2500
X0.7500
Y-0.7500
X129.2500
Y-2.2500
X0.7500
G00 Z1.5000
M05
M30

Hope this Helps, Chip

one thing that was a problem with me was i had a tool offset set up in the tool table, so i would set my height for z then when the program ran it would do my hieght and add the tool hieght also, i manualy change bits, so i removed the tool hieght from the tool table, problem fixed.
dan

Hello,

I have removed the G0 code, but the problem is the same.

I have no idea.   

Thanks for the help.

mvg

Hein

Hi, Hein

Try setting you Velocity & Acceleration down in Motor Tunning or Edit your G0's to G01, Your Z up may be slipping causing pos. loss.

Thanks, Chip

This is sounding more like pull down.

Is the tool fixed in the holder tight.

Is the Z axis moving down with vibration and cutter pull down. Fix a dial clock on the machine to monitor the Z movement.

Graham.