[ferrari77]

Apples-It is for a makerbot replicator 2, not for an FRC robot
I graduated last year and am working in a lab that is constructing a vending machine 3-d printer and to automate the part removal process we are using a stepper motor and a lead screw to push the parts off.

DELurker-It is 4 starts (8mm lead divided by 2mm pitch=4 starts) and left or right handed works for us, just a matter of running the motor the opposite direction in software. And you are right about the Acme vs Trapezoidal, I meant to just put trapezoidal as the specification.

Thanks for those links, I'm getting a price quote from Helix linear right now. We'll see how it goes