Help with project dealing with linear slide design

[Jbcolt]

I am doing a project for one of my classes where I have to design a pong player. I decided on the design of using a linear slide with lead screws to control the motion back and fourth along the table with the paddle. My question is concerning the linear speed of the lead screws vs. belt driven rails. The width of the playing field is 4ft and I need to be able to go from one side to the other in a reasonably short amount of time. So I am asking anyone that could might help me out from past experience with belt driven systems or lead/round screw drives what would be more ideal as far as cost/speed/ and degree of difficulty. Thanks in advance

PS i have a 3d sketch of the design if anyone needs a better picture of my objective.

[BillTodd]

Forget lead-screws you'd need a long pitch multi-start and that will be expensive. What you require is relatively low accuracy but fast, that says a belt drive to me

(Mike Everman's servo belt would be ideal, although its high accuracy is overkill for your application).

[eSilviu]

or this one:
Acme screw as a R&P?
I think it will work with cheap acme too.

[Al_The_Man]

For that application I would think you need high speed with high accel/decel rate, for this you need the to reduce the inertia required of all moving parts, I also would look at aluminum pulley/timing belt components.
Al.