nice great reply and links. Funny ive been searching around for the last few weeks and never hit on them. Prices look to be not astronomical.
Just converting newtons to pounds though even the biggest one with the highest gear reduction is only about 44 pounds. And thats at about .5"/s. slow. But maybe useable if I make my angle shorter so it doesnt have to push out very far.
Just blathering here... I'm going to use this for steering a ROV. So I need my wheels straight position to be at the halfway point of the stroke. To turn one direction I pull the shaft in and the other way I push it out and with no input on the joystick it should return to the "center".
I dont care about controlling the speed it goes in or out.
I think I dont care about limit switches other than to stop from burning it up. If it worked like a servo that would never be a problem because I would just never send it to end of travel in either direction.
I may need some type of controller to make it act like a servo.
Looking at http://store.firgelli.com/L16_Linear_Actuators_p/l16-p.htm
it shows an additional controller to "
Turn your L16 -P into a Linear Servo using the LAC board listed in the "Controllers and Switches" section here. This combination has all the same functionality as the L12-I plus USB support, speed control, sensitivity control, position control, and adjustable end limits.
Then I look at something like this which includes the controller:http://www.servocity.com/html/heavy_duty_linear_servo__180__.html
which has no controller but does have position feedback.
I'm thinking that with a position sensor I should be able to make it a servo right? Or is my whole problem I'll still need a controller because ITS NOT A SERVO and i cant swap polarity to run it in the other direction with out using a controller or creating some type of H bridge myself. (which i just avoided by buying a motor controller for another part of the project.)
So now I think its sounding like I need an actuator with position feedback + arduino + the other half of my Dual motor controller http://www.pololu.com/catalog/product/707
(I'm only using one side of it to control my forward and reverse drive motor)
With that I think I can create a linear actuator that acts like a servo and I already have 2 of 3 of the peices. And a prebuilt servo type actuator or one bundled with a controller is infinately more expensive than this combo that I'm thinking will work.
I have spent a lot of money trying to build things cheaper...
step 3: Profit