This last Christmas of 2014 I searched for many linear actuators on Amazon.com because I was given $70 worth of gift cards. To my surprise there are many nerd supplies on Amazon stores for the CNC hobbiest. One purchase I almost made was to buy 10 DVD drive linear actuators, just to have and play around with. Here is one such listing of 5 micro stepper motors with mini screw rods.
https://www.amazon.com/dp/B00RPXT36M/ref=cm_sw_r_awd_Gnl1ub1AXDZF6
Well Wootin24, over on Instructables.com, created a mini XYZ axis CNC controlled machine using those DVD drive linear actuators. He claims this can be used for 3D printing, too.
Check it out here:
http://www.instructables.com/id/Extremely-Low-Cost-3D-Printable-3D-Printer-Plotter/?ALLSTEPS
