<p>I am wondering how people that use standalone 3D printers (printers that have the ability to print autonomously from SD Card) feed in filament, prime the printhead and/or change filaments without a laptop ?</p>

<p>Do the printers have a menu to arrange all these tasks ?
I often only see the options to preheat the head to a certain temperature, but not to load/unload filament, extrude a small amount etc.</p>

<p>I understand this differs from printer to printer, but still am wondering about this.</p>

There are options for tablets. They are running software
(for example)
on some device that has internal storage, wifi, USB connection etc.
You can buy a new tablet, or reuse your old one just to be a controller.
Another great example is
this app
.
Apps have menus that can arrange everything for you, now it depends on what app do you use and what filament you use. It's very simple thing.