Dynomotion

Group: DynoMotion Message: 4184 From: himykabibble Date: 3/6/2012
Subject: Homing And Probing Utilities Posted To Files Section
I've just uploaded a ZIP file to Files/Home and Probe Utilities that contains some useful DSP code for doing homing and probing. The top-level files are KMotionCNCHomeHandler.c and KMotionCNCProbeHandler.c, which can be invoked as M-codes, using the P parameter to specify the axis to act on, and the parameter to specify the direction of movement. So, if this is setup as M105, then doing:

M105 P0 Q1 ==> Probe X in the + direction
M105 P2 Q-1 => Probe Z in the - direction

The Home program works exactly the same way.

The CommonDefs.h file contains serveral macros that define the operations, including the I/Os for the PROBE and HOME input pins, the maximum distance to move, the speed to move, etc. Though I have used these only in inch mode, I believe it should all work fine in mm mode as well, simply by appropriately scaling the distance and velocity parameters in CommonDefs.h.

Homing will move the (user-specified) axis at a (user-specified) "fast" feedrate, until the HOME switch triggers. It will then reverse direction, and move at a (user-specified) "slow" feedrate, until the switch releases. It will then move to the exact position where the switch released, and zero the axis.

Probing will move the (user-specified) axis at a (user-specified) "fast" feedrate, until the PROBE input triggers. It will then back off a (user-specified) distance, move back to within 0.010" of the trigger point, and move at a (user-specified) "slow" feedrate, until the PROBE input triggers. It will then zero the axis to the exact trigger point, subtracting off the thickness of the touchplate (if used)and move the axis to that exact position.

In practice, I've found these to be very robust, and reliable, and give excellent accuracy and repeatability. The basic low-level can be used unmodified to almost trivially create more complex probing functions, for doing edge-finding, mid-point-finding, 2D and 3D corner finding, circle/pocket center finding, axis alignment, complex shape probing, etc, etc.

Regards,
Ray L.
Group: DynoMotion Message: 4186 From: TK Date: 3/6/2012
Subject: Re: Homing And Probing Utilities Posted To Files Section
Thanks!

TK

On Mar 6, 2012, at 6:25 PM, "himykabibble" <jagboy@...> wrote:

 

I've just uploaded a ZIP file to Files/Home and Probe Utilities that contains some useful DSP code for doing homing and probing. The top-level files are KMotionCNCHomeHandler.c and KMotionCNCProbeHandler.c, which can be invoked as M-codes, using the P parameter to specify the axis to act on, and the parameter to specify the direction of movement. So, if this is setup as M105, then doing:

M105 P0 Q1 ==> Probe X in the + direction
M105 P2 Q-1 => Probe Z in the - direction

The Home program works exactly the same way.

The CommonDefs.h file contains serveral macros that define the operations, including the I/Os for the PROBE and HOME input pins, the maximum distance to move, the speed to move, etc. Though I have used these only in inch mode, I believe it should all work fine in mm mode as well, simply by appropriately scaling the distance and velocity parameters in CommonDefs.h.

Homing will move the (user-specified) axis at a (user-specified) "fast" feedrate, until the HOME switch triggers. It will then reverse direction, and move at a (user-specified) "slow" feedrate, until the switch releases. It will then move to the exact position where the switch released, and zero the axis.

Probing will move the (user-specified) axis at a (user-specified) "fast" feedrate, until the PROBE input triggers. It will then back off a (user-specified) distance, move back to within 0.010" of the trigger point, and move at a (user-specified) "slow" feedrate, until the PROBE input triggers. It will then zero the axis to the exact trigger point, subtracting off the thickness of the touchplate (if used)and move the axis to that exact position.

In practice, I've found these to be very robust, and reliable, and give excellent accuracy and repeatability. The basic low-level can be used unmodified to almost trivially create more complex probing functions, for doing edge-finding, mid-point-finding, 2D and 3D corner finding, circle/pocket center finding, axis alignment, complex shape probing, etc, etc.

Regards,
Ray L.