Background/Design: When attaching my laser to my ACRO system I realized I was not going to want to manually adjust the laser height. So, I designed a Z-axis system that should provide enough adjustment for my needs without adding too much height to my system. Since the lasers don't physically engage the material I figured a 3D printed system would be plenty strong enough for my needs. To keep things simple I decided to go with a stepper with an integrated 150mm lead screw. And I wanted a POM lead nut for its self-lubricating and anti-backlash properties. Using Fusion 360 I imported the ACRO X axis plate and designed rails that would sit in the long slots on the edges. I then designed the motor mount to sit atop the rails and the Z carriage with tool mount. Materials: PETG Filament (I used AmazonBasics filament in Black) NEMA 17 Stepper Motor with Integrated 150mm T8 Lead Screw T8 Nut Trapezoidal Screw Nut POM #8-16 Thread Rolling Screw for Plastic, 3/4" Length M5x20mm Thumb Screw M5 Threaded Insert Process: Based on your 3D printer you'll have to decide the best orientation to print each piece. I printed the rails with the tracks up, the motor mount with the top surface down, the carriage with the bottom surface down, and the laser mount with the front surface down. After printing, I mounted the rails to the ACRO X carriage using M5 screws and the double t-nuts with 20mm spacing. My M5 screws were a bit long, so I used washers to keep them from touching the X rails. I slid the Z carriage into the rails before tightening the rail mounting screws to ensure good fit and smooth motion. I needed to sand the carriage and rails a bit to achieve a good balance of fit/motion. I then tightened the rail mounting screws and removed the carriage. Next, I mounted the stepper/lead screw into the motor mount. I then put the threaded insert into the back of the Z carriage. This is what the thumb screw used for the laser mount threads into. I used a combination of pushing the threaded insert in then using one of the thumb screws and a washer to pull the insert all the way into place. Then, I installed the lead nut in the top of the Z carriage. I also installed a lead nut in the bottom of the carriage though it is not strictly necessary, and it complicates things a bit because the spacing of the top and bottom nut is not precise for the lead screw pitch. I needed to loosen the bottom nut when threading on the lead screw, then tighten slightly for snugness. After the assembled Z carriage was on the lead screw, I slid it into the rails and then attached the motor mount to the rails using the #8-16 x 3/4" screws. At this point is was a matter of wiring it up to my Black Box controller and testing. It took me a couple of tries to get the stepper wiring correct, but after 15-20 minutes I had it running smoothly.