Since you cant get a linear actuator for under $100 that is small enough to fit in my dash board, i thought i would make my own using a screw/nut rotary to linear conversion.... i cant seem to get the screw mounted to the 9v motor well enough so that it doesnt fly off when i give it power (i tried JB Weld and it still flew about 30ft). Does anyone know anything about acme-screw linear motors? I found this one:

http://www.myhurst.com/hurstmfg/qseries.jsp?series=Series+SL,+SBL+Synchronous+Linear+Actuator

But i just need a basic DC voltage to run it, i dont want to use their controllers or any of that shit.

Any help would be really appreciated!