@Zax
PTC Creo 4.0

@MuuSer
Oh, this is not a problem, all that is needed is to make a wider cutout at the bottom of the cam. This can provide 2-5 mm of free stroke. In actual model - 1.2 mm.

Well, the second one. If we use a standard stepper motor, then I propose using a barrel cam. I did not change the pen holder - I like it

Well, while the machine is turned on the pen will always be raised, and there should not be any problems.
To use the laser, you can completely unscrew the lifting mechanism from the rear panel and install a laser in its place. This if separately.
And if you simultaneously use both the laser and the pen - it's just the laser focus is trimmed for the fully raised holder. Thus - the holder has completely risen - we draw with a laser, the laser was turned off, the holder was lowered and we draw with a pen. I think that realize this in program is not a big problem.

Here is my idea for pen-clamp and lift mechanism. I suggest using an electromagnet to raise the pen, and to fall when the current is off, it will be under its weight. And such a slightly massive clamp will ensure that the pen is pressed against the paper.

Oh! I've found solution. Use command $3=6 - and all is OK

Hello, I have a problem with inverted Y and Z axis. I try to use Universal G-code sender(1.0.9), grblControl (0.8) and Candle(0.9). Command $2=0..7 - doesn't work, it recieve OK, I see changes in list after command $$ - but no effect for motors. Please help.