My take on a motorized Z Table for the ubiquitous K40 chinese laser.
This one is a low profile design to take advantage of the confined space in the laser. Min/Max heights (as built) are 1.5" and 4" respectively. It is also easily removed, to allow the user to switch out to a rotary Z axis if desired.
Two 608ZZ skate board bearings (or similar) are pressed into each corner. A small arbor press or a drill press is needed to seat the bearings. The bottom end of the lead screw is tapped for 8-32 low profile Phillips head screws to retain the shaft/sprocket assembly in the bearings. A little preload removes play, preventing any any side to side movement in the table.
Drive sprockets are 20 and 40 tooth GT2 and the belt is a 1350mm long, 6mm wide 675 tooth. 8mm lead screw and matching brass nuts are used.
Stepper is the standard issue 90oz torque NEMA 17 Bipolar model.
I designed the corner parts mounting holes so they could be Heli-coiled with 8-32 x .188" inserts for added fastener strength. Nuts and bolts could also be used. The center of the three holes will be used for a setscrew to level the device in the cabinet as the sheet metal in the cabinet bottom has more waves on it than lake Michigan on a calm day.
A 2.5 to 3" hole must be cut in the bottom of the cabinet so the stepper sticks out the bottom. The cabinet will need to be boosted about 2 to 2.5 inches above the table it is sitting on.
10/5/2019 I bailed on the leveling screws and used some sim washers to set the unit level. I screwed four .750 cup magnets to the underside and just use those to hold position. It is relatively easy to remove and install the table.
Also, I have designed, built and tested a limit switch for this Z Table. Hopefully will get time to post the details soon. Kinda cool to turn on Smoothie, hit home and then go into Light Burn and specify the material thickness and have it self adjust...
Seat of pants using several sources online.
Sliced with SImplify3D