ProbeApp for Centroid CNC12

ProbeApp for Mill & Routers that integrates with Centroid CNC12

Project maintained by swissi2000 Hosted on GitHub Pages — Theme by mattgraham

3 Axis Corner and Top Probing Cycle


Find the corner and top of a Rectangular Stock to set WCS 0 for X, Y and Z-Axis with one probing cycle. This probing cycle is available for all versions of CNC12.

Implementation Details

Any of the four corners of the rectangular stock can be selected. The probe needs to be placed above the Z-Surface of the corner at the approximate X and Y distance to the edge of the stock specified in the Approx. X/Y Distance from Edge. The Z Drop Down from Surface parameter specifies the distance the probe should drop down from the actual stock Z-Surface to make the edge probings. Note that the Z-Surface probing will be done first at the starting position of the probing cycle so the cycle will know the exact position of the Z-Surface when it will drop down on Z for the X and Y surface measurements. The Z Drop Down from Surface value needs to be larger than half of the probe diameter.

The probe will make the following moves and measurements:

At the end of the probing cycle, the probe will be at the corner position of the Rectangular Stock at the Probing Recovery Distance (System Parameter #13) above the Z-Surface and the Set WCS message will be displayed:

Note that this message can be surpressed if a direct WCS reset is desired withou a prior Set WCS message display. See Configuration Options for details.

Be aware that the DRO for the Z-Axis will not show 0 after the WCS reset as the probe is above the Z-Surface by the Probing Recovery Distance (System Parameter #13) when the WCS is being reset.

Probing Parameters

Approx. X/Y Distance from Edge

The Approx. X/Y Distance from Edge specifies the distance from the center of the probe at the start positionm to the X or Y edge of the stock. Under normal conditions these parameters will be set to equal values for a distance you have a good eye for and only change them when a special situation has some features that don’t allow a Z-Surface probing at the standard location.

Be generous with this distance and rather error on the plus side than being too short.

If this distance is too short, the probe will be tripped while trying to move down on Z to get to the X and Y-Surface probing height. When this happens, the retry cycle will be activated that will advance the probe in increments until it’s clear to drop down on Z. Should the retry cycle hit any limits (e.g Probing Search Distance or travel limit) the probing cycle will be aborted with an error message.

Z Drop Down from Surface

The Z Drop Down from Surface specifies the distance the probe needs to drop down past the measured Z-Surface to take the X and Y-Surface measurements.

Note that the Z Drop Down from Surface distance MUST be larger than the radius of the probe tip.

Set WCS after probing

If the WCS box is checked, at least one of the Axis needs to be checked too. By default, WCS 0 for the axis will be set at the corner position of the Rectangular Stock for the currently Active WCS.

All 3 axis allow to set WCS 0 at an Offset if needed. For an offset in the negative axis direction, a negative value needs to be entered.

Note that the available WCS numbers depend on the version of CNC12:

Any of the available WCS # can be selected to be reset by the probing cycle.

Start the Probing Cycle

After making all the selections necessary on the screen, pressing the START button will start the parameter validation. A message will be displayed if any of the parameters are missing or invalid

If no validation issues have been found, the ProbeApp will write all the necessary probing commands to


The ProbeApp will close giving control back to CNC12

At this point the Probing Cycle can be started by pressing Cycle Start or aborted with Cycle Cancle.

Closing ProbeApp without a Probing Cycle selections

The Probing Cycle screen can be closed by either pressing the X on the top right corner of the window or pressing the Green Back Arrow on the top left. This will open the ProbeApp main window where the Exit button can be pressed.

Control will go back to CNC12 where this message will be displayed:

Pressing Cycle Cancle will terminate the cycle immediately. Pressing Cycle Start will bring up this message:

Pressing Cycle Start at this point will also terminate the cycle.