Im using a small Chinese cnc machine and I don't have any trouble engraving shapes and text.
May be true, but when doing 3 axis moves with numerous small axis moves, you really need
to have steppers that can provide the accel necessary. The stepper can skip and you would
not even know it, the dro will show correctly but the actual postition will be wrong. the skipping
may be repeatable or ramdom depending on the gcode your doing.
From reply #8, you ran the following code and there was no Z problem.
You tested for a Z move of 5 mm ( .197")
M98 P123 L100
M30
O123
G90 G1 Z-5 F250
G1 Z0
M99
%
A look at the gcode you posted shows small Z moves approx range from
say .003mm to .050 ( .00011" to .002" ) for example.
I would suggest you see what the machine can do at the feedrate your calling,BUT,
test at Z distances of 4,3,2,1,.5,.1 mm's etc. You may want to just jog those distances and see
what a indicator shows. You will not move .0001" accurately as that is theoretical resolution
of your axis. If you have backlash, and you do, machining of small moves accurately just dosen't work well!
Test with only the Z, down only, then down and up and down movement and if that test is good,
add X & Y moves and test again. BTW, may want to add a pause using G4 so you can do a measurement
post move. Let us know how things go.
RICH