Simple things for simple people...
This is a very basic linear unit with only two 3D printed parts per linear drive and two identical units to form a complete x-y plotter.
No limit switches, no timing belts, just a threaded M6 rod and nut, two 6mm rods with one linear bearing each and a ball bearing with 6mm hole.
Press the nut into the opening of the printed part, using a vise.
The speed may not seem to be impressive, but every second, 150 steps are made.
If the sliding tables of two linear units are bolted together, a fully operational X-Y unit is realized.
For printing, lay the main unit flat and rotate 45 degrees along the Z-axis to fit it on a standard 20x20 bed. In this case, 5 Volt stepper motors are used. Make sure that the power supply delivers about 2 amps.
Notice the flexible tube that links the stepper shaft to the threaded rod.
An engraving laser diode is sold by AliExpress for about 15 Euro's.There are holes for mounting to a base plate and for installing the laser or a pen. If necessary, the threaded shaft can be fixed to the bearing with two M6 nuts. This plotter is very slow (compared to timing belt configurations) which is excellent for laser engraving (see example in the last movie).
An Arduino test sketch is attached (see 3d movie). First you can adjust the zero position. As soon as Start is pressed, the drawing will be made. The pen holder in the third video was just for testing purposes. I cheated a little with the speed.