The TTS-55 Pro does not come with endstops but the mainboard does support them. I designed mounts for mechanical endstops that I purchased off amazon. There are 4 locations in total. 1 on each end of each axis. These will halt the stepper motors motion in the event of trigger, and they also allow for homing the laser as well. Link to endstops: https://www.amazon.com/dp/B0921ZSL3Q?ref=ppx_yo2ov_dt_b_product_details&th=1

This can be done with just 2 endstops for homing. Use the X-axis left & Y-axis bottom models if you only want 2. I chose to take it a little further and add them on the other end of each axis to avoid it overrunning the upper limits as well. See the attached PDF for a wiring diagram if you choose to use 4 endstops.

You will need to modify these parameters in the grbl settings.

$21 = 1 (Hard limit enable)

$22 = 1 (Homing cycle enable)

$23 = 3 (Homing direction invert)

Choose the correct Y-axis bottom mount depending on if you are using the standard z axis mount for the laser that comes with it or using this z-axis adjuster https://www.amazon.com/Twotrees-Adjuster-Engraver-Control-Accessories/dp/B0B9MLKSY1?th=1

**I printed these with the endstop mount location face down on the print bed with supports.