Controlled Automation via Linear Actuator Help

There may be more than one approach to this, depending on exactly what you want to do. Many linear actuators consist of a screw driven by a motor. If the actuator needs to be stopped at various specific positions, one way is to put proximity or limit switches at those positions to shut off power to the actuator. Another way is to couple a rotary encoder to the screw, shutting off the screw when the encoder reaches a certain count. This would typically be monitored and controlled by a PLC (programmable logic controller) or other microprocessor or computer. Yet another way would be to drive the screw with a stepper motor, thereby eliminating the encoder.

It depends a lot on budget, available time, force needed, extension needed etc.

Can I suggest you look at using RC servos, they're cheap, available in many different strengths, run off ~5V and just need a low speed PWM signal. The sort of thing that can be easily provided by a small micro board.

Several cylinder manufactures offer cylinders that would provide linear motion that have internal sensor for linear positioning. You could also use a ball screw. Several machines I have here use belts and pulleys with encoded gear motor. Our machining center uses gears to travel the X axis of 16 feet. What ever you use the variance in it speed, length of stroke(with in it's mechanical design limits) and its automatic cycle are depend on the software you provide to the controller. First you need to address the mechanical aspects of your design to make a choice of which device best suits your application. What distance of motion do you need? For short distances cylinders and ball screws work well. They can be acquire in standard sizes with out the cost of special lengths. Motion of greater distances is usually done with belts or gears.

Check dakotadigital.com for a line of actuators and controls. Speed control may be a problem; call DD, maybe they can help.

Google programmable linear actuators. You can create a gantry style system by using three of them in the X, Y, & Z axis. Then instead of 3 individual programming controllers, one for each axis, use a single controller capable of controlling all 3. We use to do this on all of our automated lines for dispensing adhesive/epoxies/solder paste. Much cheaper than purchasing ready built dispensing systems.