Help finding tiny servo with lead screw

I'm looking for a small (no bigger than 25mm x 25mm x 25mm) bipolar servo motor with a lead screw around 250mm - 300mm long, with nut motion across the entire length. It needs to be in the Arduino power range. Torque requirements are quite low, the lead screw will be moving a very small piece of plastic up and down a track with virtually no resistance. Positioning accuracy to 1mm is important. Duty is light, potentially up to a dozen times used within a 10 minute period. Speed is significant, the lead screw nut should ideally traverse the screw length in under two seconds, but noise is also important.

I've been searching the Internet for days but I think maybe I need somebody with experience to advise, so my humble thanks in advance.

There seem to be several steppers out there that would do the job, but I keep reading that there is no accuracy with them. I need to be able to position the lead screw accurately, time after time.

Please finish your homework. You have given the length of your lead screw and the time for the nut to go from one end to the other. From that you need to pick a thread pitch for the lead screw/nut and from that you can compute how many turns it will take to move the nut from end to end. That will define your motor RPM and from that you will have a better chance of find a motor to fit.

Paul

It needs to be in the Arduino power range.

The Arduino should never be used to power motors. You will need a stepping motor driver and a separate power supply for a bipolar motor.

I keep reading that there is no accuracy with them.

Nonsense. A stepper driving a lead screw and a traveling nut is inherently a very accurate positioner, to microns for example. Virtually every CNC machine uses such a system for accurate machining. You do need to find out a way to accurately establish the home position.

jremington:
The Arduino should never be used to power motors. You will need a stepping motor driver and a separate power supply for a bipolar motor.
Nonsense. A stepper driving a lead screw and a traveling nut is inherently a very accurate positioner, to microns for example. Virtually every CNC machine uses such a system for accurate machining. You do need to find out a way to accurately establish the home position.

I wasn't suggesting that the motors would be powered directly from the Arduino, all I meant is that's the voltage vicinity of the circuit. I was thinking of using ULN2003's.

Thanks for the notes re accuracy and the link. I'll rethink steppers for sure.

These links may be useful

Stepper Motor Basics
Simple Stepper Code

You should modify your Original Post and change the Title so it says "steppe motor" rather than "servo"

...R

eBay or Google search "lead screw stepper motor". There's a lot out there if you look for them.

or

https://www.ebay.com/p/?iid=151802732968&lpid=82&&&ul_noapp=true&chn=ps

Here's one of many:
http://www.mpja.com/Step-Motor-with-300mm-T8-Leadscrew-for-3D-Printer/productinfo/33515+MI