Today I’ll show you how to level Z-table if you have a laser cutter similar to SH-G350, a.k.a. 50Watt eBay laser machine.
My machine came with a z-table that can be raised or lowered manually by rotating a handle. While trying to cut a 1/4″ piece of plywood I noticed that distance from laser head is greater toward the front of the machine. This causes incomplete cuts on that area. Here’s how to fix it.
First check if your z-table actually needs alignment. Move your laser head to the top left corner and adjust table to required height. I used a plastic measuring jig I made. Normally my laser focuses at 19mm from the object so that’s the distance I set my z-table to.
Now move your laser head to the top right corner and check distance. Keep moving it to other 2 corners and take a note where its lower or higher than initial corner. Even few millimeters can make a difference between perfect cut and bad one.
Disengage tension pulley that keeps timing belt tight. To do this first open front door. Then loosen pulley with a wrench and a right size allen hex key. I actually found out that I didn’t have to use allen key at all, 15mm wrench was all I needed. Keep in mind that pulley might have left hand thread. Mine was like that so I had to turn nut clockwise to loosen and counterclockwise to tighten. Loosen it until you can move pulley toward the front so it releases belt tension.
Use old rag or glove (to avoid dirt and oil getting on your hands) and turn threaded rod by hand. Do it for each corner that needs adjustment. You’ll be able to figure out which way to turn rod to raise or lower that corner. Watch for timing belt getting cough in gear and rotating other rods. Check and re-check laser head distance with each turn until it’s at correct height. Keep in mind that you have to go back and readjust few times, as turning rod in one corner will sometimes affect another corner as well.
Now that head is aligned in all 4 corners, carefully alight timing belt so it sits tight in each of the rod’s gears. Tightening timing belt may accidentally rotate some rods, you don’t want that. Now push pulley away from you until you get maximum tension on the belt and quickly tighten bottom nut with wrench.
That’s it, your z-table should now be even. Happy burning!