Linear Actuators different positions?

Hi I am pretty new to all this stuff but I need to make a set of linear actuators each have 3 different positions at the flip of a switch or the push of a button. I need a linear actuator to go from fully closed to .5’’ extended in one position and the next position go from .5" to 1" Then from there that would be considered “fully extended” (even though the shortest stroke I can buy is 2") but they would have to return from 1" to .5" then from .5" to fully closed. Is this something I can do with a JRK feedback controller and a linear actuator? What problems will I run into and what do I need to know to make this work?

Here is a video of exactly what I want to do (on a much cleaner vehicle) except I want to use electric linear actuators rather than air powered ones and I want to do it with 2 actuators rather than 4. I might even consider doing it with just one that moves both rods.

http://youtu.be/du_cIjbOoZc

Hello.

The jrk motor controller and a 2"-stroke linear actuator w/feedback should be able to perform that kind of task. You will need a separate jrk for each linear actuator.

One thing the jrk can do is take an analog voltage input and drive the actuator to the corresponding position, as defined by the jrk’s input and feedback scaling parameters. You could probably use this mode with some switches and voltage dividers to accomplish what you want.

Another thing the jrk can do is take serial commands from a microcontroller that tell it what position to drive the actuator to. If you are comfortable with embedded programming, you could program a microcontroller to interface the switches to the jrks. Several jrks can be controlled from a single microcontroller UART.

There are instructions on how to connect a linear actuator w/feedback to a jrk at the bottom of the linear actuator’s product page. You can also find more detailed information in the jrk user’s guide, found on the product page under the resources tab.

I cannot predict what problems you might run into, but if you have any trouble, we can help.

–David