I wonder, what can be harvested from deskjet printer ? What shouldn’t be left out ?
Even the weakest motor from one might be good enough from a screw driven paste extruder.
Most modern printers use DC motors, not steppers. With the exception of epson.
Right, week ago I dismantled HP printer from 2009. The only usufull items were opto enstops and ~20cm 8mm linear rod. Springs are to week/small.
Printers nowadays have very few parts that can be directly used for a 3D printer. However, if you’re a tinkerer and can use some parts for other projects, the encoder-controlled DC can be quite useful, as well as the scanner’s sensor and some power supplies.
I can find old printers in garage sale, but maybe it does not worth the effort. I have found steppers (certainly not enough torque) and smooth rods when I dismantled one.
The best ones to salvage are usually really old big ones. Like A2 format or similar. Tons of smooth rods inside, and some decent steppers. I ripped out a beefy 25V PSU out of one too. 
The thing is, even if you find one with steppers - they’re going to be way off base on their specs. Usually you’ll find 30ohm 12-24v steppers. Whereas we’re usually in the 1-4v, 2-4ohm stepper range.
Thank you all for your advices. It seems clear that I’d better buy some elements instead of struggling with non-standard harvested ones.