homingZ change from Incremental to Absolute

[ojaatka]

I have been using this PP very successfully with CNCGraf.

Since homingZ is implemented as relative movement, there are problems if the axis is too high at start. I think it would be better if the value is given as absolute value.
Then my axis would always move to a Safe-Z position.

Would that make sense?

[timschneider]

Hi @ojaatka, yes that's right - I've encountered that from time to time, when milling high parts in a vise, the problem of the CNC Graf Controller is, that it does not have a stack. I would usually do some kind of push current motion settings on stack and pop them later to do the following,

G53 ; disable WorkpiceCoordinateSystem, but it does not switch to MachineCoordinateSystem
; push current motion settings, e.g. feed rate / absoule / relative ...
G90 ; (absolute move)
G0 Z150 F2000 ; or whatever your machine is able to
; pop stored motion settings, e.g. feed rate / absoule / relative ...
G60 ; reactivate last coordinate system

Ah and an important note, the G-Code is always in WCS, so if you set Zero ontop of your vise (80mm), and try to move to 100mm absolute WCS, (180mm MCS), it's not possible for the example with Z 150mm max.

To fix your problem, you can change this with the Homing Z Parameter, just lower the value to 50 or less.