After looking at this question: Can I remotely control the points on PF train tracks? I got the idea of controlling the train track switch handle using a servo motor that will be able to move the yellow handle to both positions.

The included video in that answer: http://www.youtube.com/watch?v=WoNiq5FCd9U Shows the general idea of how to convert the circular motion of the servo motor into a kind of linear movement that will be suitable for the handle.

So it seems that with a set of Lego Technic bricks and an engine - it should be easy to achieve.

My problem is that I want to use an Arduino controller for this, with a cheap and simple servo called SG90: https://www.google.com/search?q=sg90+specifications

So, what I need now, and a way to connect the SG90 motor to a similar kind of construction, to achieve a similar outcome as in the video (and in the question).

Many thanks for that!

2 Answers 2


There are numerous solutions over internet for attaching SG90 servo with LEGO. However I remember this particular video, which fit your need to attach/control Technic beams/liftarms. It also features required parts for this build at 7:48.

  • Thanks for your looking into it, dear @Alex. Actually I've seen that video before, and if you'll notice - the most important part is missing there. Not during the video, nor in 7:48 picture - the actual pare that is connected to the SG90 moving part - is missing. You can see (in the porccess) that there is a combination of some screws and a Technic brick, but I can't identify the parts, nor the way to connect them. Thanks again!
    – Offer
    Commented Jan 10, 2020 at 13:14
  • 1
    Are you missing the white non-LEGO piece that is attached to 5L Technic beam/liftarm on bottom center at 5:16 of the same video?
    – Alex
    Commented Jan 10, 2020 at 16:11

For mounting, servo tape (strong double sided sticky tape designed for mounting lightweight servos) to a tile works fine in many cases.

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