Maintenance and Troubleshooting for the Big CNC Mill "Bessie"
Everyday usage information is located here.
Troubleshooting by Symptom
further research and specifications should be entered here. Should be easy to learn about terminal usage, component specification etc.
Service cupboard layout
Generic Troubleshooting Procedure
Opening the service cupboard
If troubleshooting without power
If illuminated, press the outer green power button to turn it off.
Open the service cupboard
Observe no lights except:
Observe spindle controller warning: AC side may retain power and must not be touched for 5 minutes
If troubleshooting with power
Ensure outer green button is illuminated, or check external power
Ensure inside IEC cable is properly seated
Observe and note locations where AC power is present:
40 volt power supply AC input terminals
5 volt power supply AC input terminals
Spindle controller AC input terminals
Water pump extension output
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.
Observe spindle controller has transitioned from dark to lit readout
Observe 3x green LEDs on stepper controllers indicating 40v supply
Verify 40 volt power supply across input terminals
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 6||Y-axis positive limit
|Limit 5||Y-axis negative limit
|Limit 4||X-axis positive limit
|Limit 3||X-axis negative limit
|Limit 2||Z-axis positive limit
There is no limit switch for Z-axis minimum. Limit 1 is unused.