Preface: The information below will cover testing the X and Y endstops to troubleshoot X or Y axis motion issues on your Thunder Laser Nova Series machine. This article includes where to source replacement endstops and additional resources are linked to extend the troubleshooting steps. This is a very long article with lots of visuals, so take your time to read and understand it completely. The endstops are 2 of the most critical sensors on the machine.
                X Axis Endstop Not Making In Time - Clunk  | Y Axis Endstop Not Making in Time - Clunk  | 
Notice the Clunk and belt flopping when the laser head goes all the way left. Then only the Y axis moves to its origin position because the X driver is faulted.  | Notice the clunk and belt popping when the gantry reaches all the way to the back. Then only the X axis moves to its origin position because the Y driver is faulted.  | 
X Axis Not Releasing/Stuck  (Very Slow Walk to the Right)  |  Y Axis Not Releasing (Slow Walk to the Front)  | 
Notice that the X axis very slowly moves to the right. Then the X axis slows down even further and moves to the right some more. Then the homing is forced done and the machine returns to an improper origin position that does not match the position readout on the control screen. The X driver is not faulted in this video but if the travel to origin has the X axis over travels beyond the limits to the right, the driver will fault.  | Notice that the Y axis very slowly moves to the front. Then the Y axis slows down even further and moves to the front some more. Then the homing is forced done and the machine returns to an improper origin position that does not match the position readout on the control screen. The Y driver is not faulted in this video but if the travel to origin has the Y axis over travels beyond the limits to the front, the driver will fault.  | 
Screen Readout  | Laser Head Position  | 
X at position 500.44 and Y at Position 500.13 on the screen  | X and Y for the laser Head are clearly not at 500.44 and 500.13  | 
Mechanical  | Legacy Optical  | Legacy Mechanical  | 
X-Axis: Left to Right  | Y Axis: Back to Front | 
Location  | Close Up | 
On larger machines it is beneficial to move the gantry bar closer to the front of the machine for access to the X-Axis Endstop  | 
Location  | Close Up  | 
You will have to open the blue door (Bolted Shut) to access the Y axis endstop  | 
Correct Wiring - Current Endstop  | Correct Wiring -Legacy Endstop  | 
Incorrect Wiring  | Wire Disconnected  | 
Wiring is on the C and NC terminals when it should be on the N and NO terminals.  | 
Normal Endstop  | Missing/Broken Off  | No Springiness\Over Extended  | 
In general, the controller is on the right hand side of the machine.
Nova Series  Internal Control Panel (Nova 24 shown, each size machine will vary but the general locations are the same)
 X-Axis LimitX- LED1 Y-Axis LimitY- LED 3 LED 1 Illuminates when the X Axis Endstop is sending a signal to the Controller LED 3 Illuminates when the Y Axis Endstop is sending a signal to the Controller
Neither Endstop Pressed  | X and Y Axis Endstop Pressed  | 
Gap is Closed - Will Cause Fault  | Gap Remains Open - Endstop Should Trigger OK  | 
Gap between laser head trolley plate and Y axis left trolley plate closed.  | Gap between laser head trolley plate and Y axis left trolley plate remains open with a properly adjusted and functioning Endstop  | 
Gap is Closed - Will Cause Fault  | Gap Remains Open - Endstop Should Trigger OK  | 
Belt Tension block hitting the gantry support bar bearing housing. Back right corner of machine.  | Gap between gantry Y axis belt tensions and bearing support housing remains open with a properly adjusted and functioning Endstop  | 
X Axis Adjustment  | Y Axis Adjustment  | 
While adjusting, it may be nice to be able to manually move the axis in question by hand so that you can make the trigger arm activate the lever arm and check the mechanical gaps. To be able to do this, you can de-energize the corresponding driver by removing the 36V power to the driver. While de-energized, you can slowly move the laser head or gantry bar by hand to make the endstop arm click. Drivers are located on the right hand side of the machine in the lower blue door area.Power should be off to the machine before plugging the driver back in. The axis will need to re-home after being powered back up.
In general, the drivers are on the right hand side of the machine.
Nova Series  Internal Control Panel (Nova 24 shown, each size machine will vary but the general locations are the same)
 CL1 Driver Energized CL1 Driver De-Energized For the older HBS drivers, they may be mounted Vertical or horizontal.
 Vertical Mounted HBS Driver Horizontal Mounted HBS Driver Remove the 5 pin connector shown to De-Energize Remove the 5 pin connector shown to De-Energize
Step 1: Remove the Wires from the Endstop  | Step 2: Remove the Mounting Bolts  | 
X-Axis Endstop Incorrect Lever Arm Direction  | X-Axis Endstop Correct Lever Arm Direction  | 
Y-Axis Endstop Incorrect Lever Arm Direction  | Y-Axis Endstop Correct Lever Arm Direction  | 
Use this adjustment to change the mechanical gap so that the axis does not fault out for closing the gap and clunking.Tools Needed:2mm Allen WrenchUse the 2mm wrench to loosen the bolts to the adjustable mounting bracket. Slide the adjustable mounting bracket with the sensor left or right as needed and then tighten the bolts.
X Axis On Laser Head  | Y Axis - Near X axis Motor  | 
On the left side at the laser head.  | Right hand side between Gantry Support rail and Drag Chain  | 
Incorrect  | Correct  | 
The gantry is too far to the left and the trigger arm is too far to make the switch signal to the controller.  | The gantry is positioned correctly and the switch is made even before getting to the flat spot of the trigger arm.  | 
| Incorrect | Correct  | 
The gantry is too far back and the trigger arm is too high to make the switch signal to the controller.  | The gantry is positioned correctly and the switch is made even before getting to the flat spot of the trigger arm.  | 

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                                 Current Endstop 
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                                 Legacy Endstop 
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                                 Currently used as the Z limit switch but was also used as the X and Y 
                                endstops as well. (Link Here) 
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