Height Offset Problem

[Nigelo]

FWIW, a simple way of setting your machine to use Z home as Z-ref is to set Parameter 3 from the default 0 to 2 (or 6 as Uwe suggested to you). This is covered in the Mill manual at 15.3.5 "Modal Tool and Height Offset Control". You then setup your tool height offsets, including the probe (your KP3), using your usual touch off device noting that the KP3 will NOT have a zero offset. With this method, all tool offsets are the actual distance between that tool's Z home and your touch off device.

You are then free to change the KP3 stylus or holder, if required, without having to remeasure the rest of your tools - Just remeasure the KP3 after such change.

The above method allows me to share my DP4 (KP3 predecessor) with fixed tool holder for my Mill and ER25 collet chuck on my Router.

Note that your most recent Report.Zip shows your KP3 is shown as 0 offset and you are still running cnc12 v4.80 which is long overdue for updating.

Hope this helps

[RJS100]

Thanks for your input. I do understand the concept of using Z-home as the reference. I did indeed try using 2 and 6 for parameter 3 while attempting to use Z home as the reference and could not make it work properly. FYI, I do not see a section 15.3.5 with this heading.

At this point, this feature is not really that important for me. Using a master tool for the z reference is fine for my setup.

My bigger concern is that I get the correct information when I use single axis probing just before running g-code, but incorrect info after running g-code.

I recently considered upgrading from CNC12 v4.80 and was told not to bother if I did not need the newest features. I'm not sure if this is a bug with 4.80 and now need to upgrade.

Thanks... Richard

[suntravel]

This is not a bug in 4.8

Uwe

[RJS100]

Thanks Uwe. Probably something I am doing wrong. Here is a quick video showing my steps:

1: Set WCS for z: https://www.dropbox.com/scl/fi/er1htend ... z8v7s&dl=0

2: Probe the same surface with single axis probing cycle: https://www.dropbox.com/scl/fi/o41u0jnv ... tns7u&dl=0

3: Run simple gcode: https://www.dropbox.com/scl/fi/xoku5v7b ... cjry2&dl=0

4: Probe same surface again: https://www.dropbox.com/scl/fi/ac0khia0 ... vu9b3&dl=0

Ok.. Where have I gone wrong here?

Thanks... Richard

[suntravel]

First probing T4 H100
Second probing T4 H4

That makes the difference. Hxxx is the tool length offset

Uwe

[RJS100]

I am confused. With both probing cycles, I specified tool# 100 (the probe). So why are different tool offsets being used and why do they differ before and after running gcode?

[Nigelo]

Thanks for your input. I do understand the concept of using Z-home as the reference. I did indeed try using 2 and 6 for parameter 3 while attempting to use Z home as the reference and could not make it work properly. FYI, I do not see a section 15.3.5 with this heading.

At this point, this feature is not really that important for me. Using a master tool for the z reference is fine for my setup.

My bigger concern is that I get the correct information when I use single axis probing just before running g-code, but incorrect info after running g-code.

I recently considered upgrading from CNC12 v4.80 and was told not to bother if I did not need the newest features. I'm not sure if this is a bug with 4.80 and now need to upgrade.

Thanks... Richard

Not sure who told you not to update but Centroid support on this forum does not cover old versions. Updates are not just new features but bug fixes too.

The manual I refer to is that with the current version v5.06. Download the latest manual version on this forum under All Acorn Documentation

[RJS100]

Sorry... was looking in the correct manual, just swapped the numbers. I will update to the latest CNC12, however Uwe in the previous post suggest that this is not a bug. Unfortunately, I am unable to follow his comment. I do not understand why if I am using tool #100 (my probe), that I get different results before and after running gcode. It is my understanding that the refence point would always be the same unless I changed WCS, which I did not.

[cncsnw]

One way to get "different results before and after running G code" is if the G code program ends with G49 and/or H0. Then any tool height offset that was active before you ran the program would be canceled when the program is done running.

Watch the "Tool:" display in the status window in the upper right. The 'H' number tells you what tool height offset is currently active and being applied to the DRO.

[RJS100]

Thanks. The gcode I ran is really simple. Here it is and I do not see either G49 or H0

%
O01034
(1034)
(T4 D=0.25 ZMIN=-0.005 - flat end mill - 1/4" x .75" x 2.5" END MILL)
N10 G90 G94 G17
N15 G20
(Face1 (3))
(When using Fusion 360 for Personal Use, the feedrate of)
(rapid moves is reduced to match the feedrate of cutting)
(moves, which can increase machining time. Unrestricted rapid)
(moves are available with a Fusion 360 Subscription.)
N20 G28 G91 Z0.
N25 G90
N30 T4 M6
N35 S3000 M3
N40 G54
N50 G0 X2.19 Y-0.6574
N55 G43 Z0.4 H4
N60 M7
N65 G1 Z0.1 F8.
N70 Z-0.005 F20.
N75 X-0.25 F8.
N80 G2 Y-0.4619 I0. J0.0978
N85 G1 X2.19
N90 G3 Y-0.2663 I0. J0.0978
N95 G1 X-0.25
N100 G2 Y-0.0707 I0. J0.0978
N105 G1 X2.19
N110 Z0.4
N120 M9
N125 G28 G91 Z0.
N130 G28 X0. Y0.
N135 M30
%