Servomotor Smooth Moves

Thread Starter


Joined Mar 29, 2022
I need a servomotor to perform a movement that is not abrupt (organic movement). This type of movement is smooth just like in the attached video.



Joined Jul 18, 2013
This is typically achieved with PID Servo control, as is seen in industrial robotics and CNC etc.
Also known as interpolated motion and positioning.
Last edited:


Joined Nov 6, 2012
It's also very important to get your "Gearing" and "Linkage" right.
You need to determine the fastest-speed that the movement will ever need when operating,
then gear the Motor so that during that "fastest-speed-move" the Motor will be running at
a minimum of ~50% to ~75% of it's rated maximum RPM,
this speed should be ideally set at what ever the "sweet-spot" of the Motor happens to be.
Studying the Performance-Curves in the Spec-Sheet of the Motor should
show You at what RPM / Current parameters this "sweet-spot" occurs,
( generally speaking, it will be at the point of maximum peak Horsepower ).

Also check the angles of any Crank-Mechanisms or Levers that
the motion may be being transferred through from the Motor to the object being moved.
Ideally, the speed of motion, relative to the RPM of the Motor
should be completely Linear from "stop-to-stop" over the total travel of the object.

In other words, the object's motion doesn't speed-up, or slow-down,
throughout it's complete travel, ( pay particular attention to the very ends of maximum travel ),
with the Motor maintaining a fixed RPM.

And like Max said, your PID configuration must be spot-on.


Joined Jan 27, 2019
Is there some reason why you can’t use the method described in the video which provides an ease-out technique by mathematically providing a deceleration curve?

He offers a very simple method to achieve it, which should be easy to adapt to whatever configuration you are using.