Ellis
USA
Asked
— Edited
I have looked on the community and don't seem to be able to find a simple answer on how to control a Linear actuator.
What I am doing is making my Tin Man robot upper body rise up or down on command. I have a 12" actuator. It has two wires. To change directions you reverse the two wires. I would like to use one half of a Hbridge motor control. The motor control I have is a two in one Hbridge. I thought of using a movement control but I already have one controlling the wheels.
The linear actuator is moved by a 12v dc motor. I will power the actuator with 12v from my two twelve volt lead acid batteries. Do I just control the Hbridge with servo code. My linear actuator has limits up and down.
will - those are great videos but they don't have positioning feedback so it doesn't work like a servo - a servo knows the position. This example you've provided only allows controlling the speed of a motor by means of an r/c servo input.
By having a potentiometer added to the actuator, the example i provided throughout this conversation would allow a servo control actually act as a servo - not control speed.
The conversation was never about controlling speed using a servo control. The conversation was about controlling output position like a servo does.
While there's been a bunch of input, no one read my posts with the intent of understanding the content. The purpose of my contribution was to provide a very simple and elegant solution that allows a linear actuator to act as a servo with precise control of positioning.
I recommend revisiting my previous posts in this thread. If I find time, i can draw a sketch for you - because i know this approach will be beneficial to many of you who create custom robots.
For long travel actuators a string pot works great. You can buy or build one. Pull the board out of a servo, hook the string pot to the where the old servo pot connected, connect the servo motor wires to an h bridge, connect the actuator motor wires to the h bridge out wires and you have a linear servo.
For short travel actuators, connect a spring loaded lever to the pot shaft, and connect a string to the end of the actuator or part you are moving. Wire this up the same as listed above.
I have used this in the past and it does work. You will need to mess with the pot values to get it to match the travel you want.
With the actuator Will mentioned, ( @$ 67.00) you can build a low cost servo for less than $150.00 with controller.
Hello everyone! Thank you all for the information in the thread! I am attempting to control a home made actuator with the hacked micro servo POT (following DJ’s suggestion for turning my actuator essentially into a servo) and am wondering where exactly the two wires (that would normally connect to the servo motor) plug into the H bridge. I’m using a an standard L298 bridge and a Pololu 12v motor.
Any help is appreciated!
They connect to one of the Hbridge channel dual inputs.
Thank you DJ!