no logic x/y machine

[aegfurn]

I am building a paint spraying machine. The spray head needs to move in the +y direction to the end of travel. Then the x needs to advance 4" or so. Then -y to the end of travel, x advance, then start over.
Is it possible to do all this with relays and leave the computer out of it?
Thanks,
Pete

[Al_The_Man]

What you are describing is a point to point machine, and it can be done fairly simply as you suggest, I would look at a Smart Relay like Siemens Logo, others re-label the exact same item, Idec, Omron etc.
It is fairly simple logic programming and you do not need special software.
As to the motor control, If precise positioning is not required, Then anything from switching a DC motor on/off or set up a train of pulses with a simple 555 generator oscillator to operate into stepper drives.
The steppers may give you close to exact positioning as when you turn them off they stop almost instantly.
Al.