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.

Quick Start Video:

**coming soon**

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Complete Guide:

There are multiple types of switches depending on the vintage of your machine. The mechanical switches differ from the optical sensors that are in the visuals but the principle is the same. Instead of a mechanical lever, the switch is activated by breaking the beam of light between the forks.

      You likely arrived at this article because one of you axes of motion is not moving after a power up, re-home, reset etc. This is often caused by the endstop not being made before the laser head reaches the hard end of travel limits (metal on metal). Another scenario can be the direction wire on the driver but that is typically pretty rare. If you have recently cleaned your machine, there is a chance that you over-extended the arm of the endstop and broke it.

Homing Examples:

This is a set of videos of showing what to expect and what to look for. If your machine exhibits a Clunk or Slow walk, it would be good to continue through this guide to learn about the Endstops, Test the Endstops and then Adjust or Replace if necessary.

Normal Homing to the back left and then returning to a User Origin:

Here are some problematic Homing cycles that indicate a possible endstop issue:

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.

Indications of a bad homing sequence at startup:

-Loss of Axis Control - Driver has 7 Red Flashes

-X or Y Position values on Laser Screen after Homing is incorrect. Compare the physical position of the head against what the screen says the position is and compare.

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

-Laser Head does not return to the correct User Origin after Homing for both Axes. For example, the X Axis Head moves but the Y Axis gantry stays put at the back of the machine.

Various Endstop Types:

Mechanical	Legacy Optical	Legacy Mechanical

Identify Control Axis for each Endstop:

It is important to know which Endstop controls which motor direction in order to be able to troubleshoot efficiently.

X-Axis: Left to Right	Y Axis: Back to Front

X-Axis

The X-Axis endstop is on the left side of the gantry and moves up and down on the gantry.

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

Y-Axis

The Y-Axis is on the right hand side of the gantry track support. You will need to open up the door on the right hand side of the machine which is bolted shut from the inside.

Location	Close Up
You will have to open the blue door (Bolted Shut) to access the Y axis endstop

*on Legacy machines, the Y endstop was located on the left hand side gantry track support and may have been an optical sensor

The wiring on the endstop should connect to the COM and NO pins. The endstop will light up the corresponding LED on the RUIDA controller when pressed.

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.

If a wire was wrong or not landed, install it back properly and then power the machine back up to initiate a homing routing.

The endstop Lever should be in good working condition. Please verify the state of the lever arm.

Normal Endstop	Missing/Broken Off	No Springiness\Over Extended

If the lever is missing, broken or has lost its springiness, then you should replace the endstop

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

The diagnostics screen will show you that the controller is receiving the signal when you test the endstop by pressing on the Lever Arm. The corresponding box should turn red when testing the endstop. To get to the diagnostics screen, press the MENU button, then scroll down and press the ENTER button when on the selection for Diagnostics.

Neither Endstop Pressed	X and Y Axis Endstop Pressed

      The Endstop should be adjusted so that the mechanical gap is not closed between the Gantry/Head and the physical barriers that they will hit if they over travel. If the switch position needs adjustment, see the section below about adjustment. If the mechanical gap is closing while homing or under normal operation, the driver will fault out and will require being power cycled to clear the fault.

X Axis

When the laser head travels to the left to home, there should be a gap between the the Laser Head Trolley plate and the Y Axis Trolley plate.

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

Y Axis

When the gantry travels to the back of the machine to make the Endstop, there should be a gap between the belt tension block and the bearing housing.

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

If you suspect the head or gantry is reaching the hard travel limit before making the endstop, then the switch should be moved away from the hard end of travel (For X axis that is to the right, for the Y axis that is to the left which is towards the front of the machine. Pease see the section down below on how to adjust.

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 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. 

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

Tools Needed:

1.5mm Allen Wrench

Spare Endstop

Step 1: Remove the Wires from the Endstop	Step 2: Remove the Mounting Bolts

Re-Install in reverse. Make sure the arm is pointed in the correct direction.

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

After replacing, go back and check the function and adjust as needed using the techniques listed above in this article

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 Wrench

Use 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.

If after checking the endstops you have still not found and issue and you think that you have a driver, motor issue, let's perform this test and email the results to Support@thunderlaserusa.com. A short video or a very detailed, exact play by play of what happens should be provided.

1. Power off your machine

2. Manually move the laser head half way to the right (X direction) and the gantry(Y direction) ~10" towards the front of the machine. There will be some resistance, move slowly.

3. Power Up the machine and observe the action of both the X and Y Axes

4.  After homing is complete, try to jog the X and Y Axis.

If the X and Y axis both move, Congratulations, you fixed it. If not then answer theses questions:

Did the X Axis Laser head move left? Did you hear a "clunk" when it reaches it's end of travel? Are there 7 red flashes on the X Axis Driver? If so, check and adjust the X axis endstop again

Did the Gantry move towards the back of the machine? Did you hear a "clunk" when it reaches it's end of travel? Are there 7 red flashes on the Y Axis Driver? If so, check and adjust the Y axis endstop again

Did the laser move very slowly to the right or towards the front? The switch is not releasing, likely broken so it should be replaced.

Did an axis not move at all? Check for 7 red flashes. You may have a driver, motor or cabling issue. Email Support@thunderlaserusa.com with what you have found.

If you do not think it is the endstop and may be the Direction Pin wiring, please see the article listed in the additional resources about Checking the Direction wire for each axis.

Where to buy replacement Endstops:

Firstly, check your toolbox as one was included when the machine shipped. If not, click the pictures below to purchase in the Thunder Laser USA Ecom store.

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

Additional Resources:

X and Y Sensor Flag Deformation Can Cause Erratic Motion Control & Crashes
What do the Red LED Lights on the Ruida Controller Mean for Nova and Odin Lasers

Checking X Driver Direction Wire

Checking Y Driver Direction Wire

X and Y Sensor Flag Deformation Can Cause Erratic Motion Control & Crashes