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project:cchs:cnc_milling:bessie_maintenance

Maintenance and Troubleshooting for the Big CNC Mill "Bessie"

Opening Notes

Everyday usage information is located here.

Troubleshooting by Symptom

System Reference

FIXME further research and specifications should be entered here. Should be easy to learn about terminal usage, component specification etc.

Mach3 Controller

Mach3 controller top view

Stepper Driver

Stepper driver

Spindle Driver

Spindle Driver

Service cupboard layout

Service cupboard back left Service cupboard back right Service cupboard front left Service cupboard front right

Generic Troubleshooting Procedure

Opening the service cupboard

If troubleshooting without power

  1. If illuminated, press the outer green power button to turn it off.
  2. Open the service cupboard
  3. Observe no lights except:
    • one blinking red LED on the mach3 controller (USB power)
    • Spindle controller may retain power for ~20 seconds before powering down
  4. Observe spindle controller warning: AC side may retain power and must not be touched for 5 minutes

If troubleshooting with power

  1. Ensure outer green button is illuminated, or check external power
  2. Ensure inside IEC cable is properly seated
  3. Observe and note locations where AC power is present:
    • AC filter
    • 40 volt power supply AC input terminals
    • 5 volt power supply AC input terminals
    • Spindle controller AC input terminals
    • Water pump extension output

Input filter 240v40v-psu 240v5v-psu 240vSpindle-driver 240vWater pump lead 240v

Checking power distribution

Requires service cabinet access.

Perform power-troubleshooting checks above before proceeding.

40 volt stepper power supply

Verify 40 volts across output terminals.

Be sure to measure from the lowest ground connector, as the highest one has 240v neutral above it.


5 volt logic power supply

Verify 5 volts across output terminals.


Spindle controller

Observe spindle controller has transitioned from dark to lit readout


Stepper drivers

Observe 3x green LEDs on stepper controllers indicating 40v supply

Verify 40 volt power supply across input terminals


Mach3 controller

Observe blinking red LED on Mach3 controller indicating USB power

Verify 5 volt power supply across the DC5V and 0V terminals

Checking limit switches

When Mach3 detects a limit switch trip the controller should halt the servos. Mach3 will indicate the condition and request the user to press reset.

While switches are not triggered they remain open and we measure about 5v between ground and the limit terminal. Closing the switches brings the voltage to about zero.

Limit switch allocations are:

Limit 6Y-axis positive limit
Limit 5Y-axis negative limit
Limit 4X-axis positive limit
Limit 3X-axis negative limit
Limit 2Z-axis positive limit
Limit 1

There is no limit switch for Z-axis minimum. Limit 1 is unused.

project/cchs/cnc_milling/bessie_maintenance.txt · Last modified: 2015/04/17 07:28 by projectgus