[amirh]

Hi,

I have built a new 3 axis mill machine, however my axes has a small angular error.

In other software (which I don't like there is a formula axis correction where you can compensate for angular error and square up your machine.

another use is if the stock is not being held strait then I can correct the coordinate to the work piece coordinate. I do that by sampling the stock using a Z zero plate sensor.

What is the equivalent in linuxcnc?

[alan_3301]

check this thread out its handy if you have a probe
http://www.cnczone.com/forums/linuxc..._function.html

or if you dont have a probe you can use an edge finder and the routines which I copied for the files in the previous link here. JT?s LinuxCNC Stuff Go to bottom of page. examples are there.

These will help if you are trying to correct xy misalignment, to rotate around Z axis. The core of this is the command G10 L2 P0 R5
Where 5 would be a positive 5 degree rotation offset in the current coordinate system.
You can read more about this command here: G Codes

If you were talking about compensating for a uneven Z plane, then you can use the module probekins instead of trivkins which is the default.
Do a google search for probekins to learn about that.

[chester88]

Can you use a compensation file? from the manual:



COMP_FILE = file.extension - A file holding compensation structure for the axis. The file could be named xscrew.comp, for example, for the X axis. File names are case sensitive and can contain letters and/or numbers. The values are triplets per line separated by a space. The first value is nominal (where it should be). The second and third values depend on the setting of COMP_FILE_TYPE. Currently the limit inside LinuxCNC is for 256 triplets per axis. If COMP_FILE is specified, BACKLASH is ignored. Compensation file values are in machine units.

COMP_FILE_TYPE = 0 or 1 -

If 0: The second and third values specify the forward position (where the axis is while traveling forward) and the reverse position (where the axis is while traveling reverse), positions which correspond to the nominal position.'

If 1: The second and third values specify the forward trim (how far from nominal while traveling forward) and the reverse trim (how far from nominal while traveling in reverse), positions which correspond to the nominal position.

Example triplet with COMP_FILE_TYPE = 0: 1.00 1.01 0.99 +
Example triplet with COMP_FILE_TYPE = 1: 1.00 0.01 -0.01

[jensor]

Question on last post concerning COMP_FILE.

Can you use a compensation file? from the manual:



COMP_FILE = file.extension - A file holding compensation structure for the axis. The file could be named xscrew.comp, for example, for the X axis. File names are case sensitive and can contain letters and/or numbers. The values are triplets per line separated by a space. The first value is nominal (where it should be). The second and third values depend on the setting of COMP_FILE_TYPE. Currently the limit inside LinuxCNC is for 256 triplets per axis. If COMP_FILE is specified, BACKLASH is ignored. Compensation file values are in machine units.

COMP_FILE_TYPE = 0 or 1 -

If 0: The second and third values specify the forward position (where the axis is while traveling forward) and the reverse position (where the axis is while traveling reverse), positions which correspond to the nominal position.'

If 1: The second and third values specify the forward trim (how far from nominal while traveling forward) and the reverse trim (how far from nominal while traveling in reverse), positions which correspond to the nominal position.

Example triplet with COMP_FILE_TYPE = 0: 1.00 1.01 0.99 +
Example triplet with COMP_FILE_TYPE = 1: 1.00 0.01 -0.01

In the above what is definition of forward and reverse direction? On my machine I move in a positive or a negetive direction definitely not for ward or reverse.

jensor