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Z Axis


General Information

Symptom
Applicable Revisions
Tool dives into touch plate or does not trigger a Probe Active signal when using Auto-Z Procedure. 🔗
All
Possible Cause Corrective Action

The Auto-Z Touch Plate is not plugged into the AUX1 port on the Plug-and-Play Controller.

Ensure the Auto-Z Touch Plate cable is connected to the AUX1 port and fully seated and secured.

More information:

To test the Auto-Z Touchplate signal, place the magnet on the brass surface. If Mach4 is receiving the signal from the touch plate, the Probe Signal indicator below the Auto-Z Touch Plate button should change from Inactive to Active .

The Auto-Z Touch Plate magnet is not attached or has an inconsistent connection with the tool or spindle nose.

Ensure the Auto-Z Touch Plate magnet is securely connected to the tool or spindle nose.

Motion Issues

Symptom
Applicable Revisions
The machine does not jog when commanded with Mach4 connected and machine enabled. 🔗
All
Possible Cause Corrective Action

Keyboard Jogging is not enabled in Mach4.

Turn the "Keyboard Jog" toggle to ON.

More information:

Avid CNC Mach4 Users Guide

Axis only moves in one direction regardless of jog direction. 🔗
All
Possible Cause Corrective Action

CRP850-00E breakout board is not firmly seated into motor drivers, leading to motion in only one direction.

Reseat CRP850-00E breakout board into motor drivers to ensure all motors are receiving step and direction signals

Electrical Issues

Symptom
Applicable Revisions
The machine does not jog when commanded with Mach4 connected and machine enabled. 🔗
All
Possible Cause Corrective Action

Motor enable/disable switch is in the 'Off' position.

Check switch position and set to the 'On' position.

Intermittent loss of motion while jogging or cutting. 🔗
All
Possible Cause Corrective Action

Intermittent ethernet connection between Mach4 and the ESS due to a faulty ethernet cable, USB ethernet adapter, or USB port.

Perform the following tests to eliminate the ethernet cable/adapter as the cause of motion loss:

  1. Test with known good cable, between computer and Plug & Play Controller.

  2. Bypassing the panel mount connector on the Plug & Play Controller by plugging ethernet directly into the ESS board.

  3. Test with a known good USB-to-Ethernet adapter or new adapter.

  4. Test ethernet adapter plugged into an alternate USB port.

Replace cable or adapter if necessary.

Loose power supply wiring in the Plug and Play controller.

Turn off and unplug power from the controller.

Check the 5V and 12V power supply input and output wiring is secure. If necessary, reseat and firmly tighten connections.

Check the 5V power wiring on the ESS (12V on WarpRunner/TMC3in1 for Plasma controllers) and secure if necessary.

Loose breakout board connection in the Plug and Play controller.

Turn off and unplug power from the controller.

Check that the CRP850-00E breakout board is firmly seated in the motor drives.

For Plasma controllers, check that the WarpRunner or TMC3in1 breakout board is firmly seated in the ESS connection.

Loose motor control wiring in the Plug and Play controller.

Turn off and unplug power from the controller.

Check that all motor drive connections are secure.

More information:

Motor Drive Connections

Software Issues

Symptom
Applicable Revisions
The cutting tool cannot reach the spoilboard, even if the axis is reaching the lower soft limit and the spindle is mounted per our instructions. 🔗
Avid CNC Mach4 profile v2.1.1 and older
Possible Cause Corrective Action

The soft limits are set too conservatively by default preventing the axis from reaching its true lower limit.

Note: This is most often seen on machines equipped with 12" Z Axis.

Option 1: Update Mach4 to latest version.

Option 2: Adjust the Z axis soft limit manually in Mach4 by navigating to: Configure -> Control -> Homing/Soft Limits.

More information:

Avid CNC Mach4 Download

Intermittent loss of motion while jogging or cutting. 🔗
All
Possible Cause Corrective Action

There may be corruption of the network adapter settings that is causing connection interruptions.

Perform Windows Network Reset then rerun SCU application.

More information:

Network Reset Instructions

Homing Issues

Symptom
Applicable Revisions
Machine does not stop at end of travel and sensor not tripped, often while homing. 🔗
All
Possible Cause Corrective Action

Sensor flag or sensor not positioned correctly.

Ensure the sensor and/or sensor flag is positioned such that the sensor is triggered without contact between the moving assembly and rubber bumper.

More information:

Y Axis (table) Sensor Flag Instructions

X Axis (gantry) Proximity Sensor Instructions

Z Axis Proximity Sensor Instructions

Machine completes homing sequence without moving all axes to home position 🔗
All
Possible Cause Corrective Action

Axis homing order incorrectly assigned after Mach4 configuration.

Note: Assigning homing order is only necessary on multi-process and shared sensor port machine.

  1. In the Avid CNC Mach4 Configuration menu, choose the "Use custom homing settings" option.

  2. Set the axis homing order as needed so that axes sharing a sensor port do not home simultaneously.

More information:

Mach4 Custom Configuration Menu

Assigning Homing Order

Noises

Symptom
Applicable Revisions
Regular or rhythmic squeak coming from the top (motor side) of the axis. 🔗
All
Possible Cause Corrective Action

Oldham coupler motor half is positioned too far from the motor.

Reposition Oldham coupler half as shown in the instructions.

More information:

NEMA 23 Instructions

NEMA 34 Instructions

Accuracy & Cut Quality

Symptom
Applicable Revisions
Holes/pockets cut at an increasingly shallower or deeper depth over the course of a program. 🔗
All
Possible Cause Corrective Action

The tool has moved up/down in the collet while cutting.

Check that the collet is free of debris and the nut is adequately tightened.

Hole/pocket cut depth inconsistent within a single program. 🔗
All
Possible Cause Corrective Action

Inadequate workholding is allowing the material to flex upward/downward.

Addtional or alternative workholding solutions may be required to eliminate movement in material while cutting.

More information:

Thin materials often require additional attachment to spoilboard in the middle of parts. Thicker double-sided foam tape is strongly discouraged as it can allow significant vibration while cutting.

Work offset shifted or not aligned with material corner after using touch plate to set all axes. 🔗
All
Possible Cause Corrective Action

Tool diameter was not set correctly in the touch plate dialog window.

Ensure the diameter entered matches the diameter of the tool being used and re-run the touch off routine.

More information:

Auto Z Touch Plate Tutorial

Holes or pockets are cut at an increasingly shallower depth over the length of a program, often a program with a large number of "drilled" holes or plunge moves with an endmill. 🔗
All
Possible Cause Corrective Action

Drilling or vertical plunge moves caused a momentary loss of motion/steps due to excessive load leading to the physical tool height being above the position in Mach4.

End mills are not designed to drill or plunge vertically at significant speed. It is recommended that a ramp or lead-in be used for pockets. If drilling a large number of holes is required, a cutting tool smaller than the desired hole diameter and a helical bore tool path is recommended in place of a vertical plunge.

These strategies reduce vertical loading on the tool and Z-axis while also providing an exit path for chips which reduces heat buildup, leading to increased tool life.

More information:

Toolpaths, Speeds, & Feeds Video Playlist

Small loss of cutting height over the duration of a program with a large number of Z Axis movements. 🔗
Avid CNC Mach4 profile v2.0.6 and older
Possible Cause Corrective Action

Unused height control setting in Mach4 can lead to incremental creep of Z Axis position.

Upgrading to the latest release of Mach4 will eliminate this issue. The latest version disables height control and includes bug fixes for improved reliability.

More information:

Avid CNC Mach4 Download

Error Messages

Symptom
Applicable Revisions
Soft limits reached while cutting. 🔗
All
Possible Cause Corrective Action

Program extents may be outside of the area defined by soft limits.

In Mach4 with work coordinates set and G-code loaded, click Regen Toolpath to the right of the toolpath preview window.

Inspect preview for cutting moves (green lines) or jog moves (white lines) that fall outside the machine work area (dashed yellow line).

Any lines outside the work area will trigger a soft limit error. If found, reprogram toolpaths to ensure the program stays within the set work area.

More information:

Mach4 has a "look ahead" feature which analyzes upcoming lines of G-code to ensure no command contains errors or exceeds the machine work area. The default setting is 20, meaning Mach4 is always reading 20 lines ahead. Because of this feature, a soft limit can be triggered well before the machine would have been commanded to move outside of the work area.

Z Axis limit switch triggered while program running and Z Axis not located near sensor. 🔗
All
Possible Cause Corrective Action

The dust collection hose may have triggered the proximity sensor. Dust hoses often contain metal coils.

Secure dust collection hose or shroud sensor such that a false limit cannot be triggered by moving hose.

Other

Symptom
Applicable Revisions
Depth of cut is too high, by approximately the material thickness. 🔗
All
Possible Cause Corrective Action

Material origin is defined at bottom of the material in CAM software.

Option 1: Reprogram with origin set at the top surface of the material.

Option 2: Set Z height with touch plate on spoilboard surface instead of the top surface of the material.

More information:

With a flat spoilboard, zeroing to the spoilboard surface will provide more accurate thickness in pocketed areas without accurately accounting for material thickness.

For example, shallower than expected dado depth can affect the overall outside dimensions of assembled cabinets. This can lead to an increase in the overall length of a run of cabinets.