Understanding the feedback Linear Act. with 18v15

Hello all,

Need some clarity please.

My project is a large linear actuator with feedback, LACT8P.

It will control steering on a boat.

I am currently using a non-feedback Linear actuator with the 18v15 motor controller.

My Steering wheel presently has a 10k pot mounted on the shaft that does work with the 18v15, however it does not return to center and I knew that it would not. What I didn’t know was that returning to center is a needed function. So I intend on changing that aspect.

What I’d like to understand/know is this:

Will the 18v15 allow me to use the LACT8P AND have it return to center when the steering wheel gives it a centering command?
I need that actuator to come back to it’s centered position, ie, half way point of total stroke.

The 18v15 was a breeze to set-up with the Quick Set-Up Wizard.

Thanks in advance for all helpful insight.


If you want the linear actuator to return to the center reliably, you will need a system that can do closed-loop position control. The Simple Motor Controller 18v15 does not have position feedback control built-in; however, you might be able to add a microcontroller to read the built-in potentiometer on the linear actuator for position feedback and command the linear actuator based on the reading.

If you are looking for a motor controller that supports position feedback, you might consider our jrk motor controllers. For your linear actuator, we provide instructions for connecting it to a jrk 21v3 on the bottom of actuator’s product page; however, you might still have to adjust some of the settings.

By the way, it sounds like your project could potentially be dangerous. Please note, we do not recommend using our products for applications where failure can cause personal injury.

- Jeremy

Hi Jeremey_T,

Appreciate the response. I had had that actuator on a micro-controller before and like the idea of a separate system, like using Pololu Motor Controllers. Adjusting the data doesn’t bother me and in fact pleases me. As it stands now sounds like I’d do well to buy the Jrk MC and a Linear actuator with FB. That said, I did notice that the 18v15 can use/interface with an R/C controller so that was the impetus for my question. I’m guessing the typical R/C joysticks must do something I am not aware of? As in, when they pop back to center don’t they give a centering command? Just curious~

None the less, on the comment about dangerous/personal injury. I don’t blame you guys for that. Shame that this litigious society wants to blame others.
Rant: Batteries for instance. How many folks can say they’ve had a battery explode? Not many, but it happens. Should we blame the maker of the battery? Life’s dangerous. /rant :open_mouth:

Thanks again!

In a typical setup using an RC signal as the input for the Simple Motor Controller, the joystick position on the RC transmitter will correspond with the motor’s speed. When using the SMC with a linear actuator, setting the joystick to the neutral point will cause the linear actuator to stop moving (to the SMC, the linear actuator looks like a brushed DC motor). You can read more about this in the “Connecting an RC Receiver” section of the Simple Motor Controller user’s guide.

- Jeremy


Thanks for your help. I went ahead and ordered those two pieces.