linear motion

Let me create a scenario to better illustrate the problem I have 1500 pens that I want to individually actuate upwards with 3 different distances, ex: 10mm/15mm/20mm I thought I could use solenoids to do this, but I'm not sure if this is the best option and how accurate the solenoid will be...

I've designed my own height adjustable, small gantry crane for my hobby shop, perfectly sized to collapse just small enough to get under my regular-car garage doors, and yet expandable up to 9.5 ft to utilize the full ceiling height of my shop. The design has been mostly dictated by materials I...