I have gotten lots of requests on how I built my automated laser pointer (ALP). If you don’t know what I’m talking about, you should visit my Instagram page and watch some reels of it dancing! If you like what you see, consider giving me a follow to keep up to date with the project.
This guide will walk you through the design of the (ALP), mainly to include the 3D printed parts that are used to put this whole thing together. I’ve released one guide on how to control a single servo via a Raspberry Pi and Python, but an additional guide will come out soon explaining the ALP’s code as a whole.
What You’ll Need
For this project, I used a 3D printer to make my own custom parts. These parts were built to fit the specific servo motor that I found. If you are interested in recreating my project, I strongly recommend that you buy the same servo motors.
Check Out the Servo Motors I Use
The laser pointer itself is a simple circuit component that can be bought for cheap. Both 3.3V and 5V options are available, I choose the 5V option for myself.
Check Out the Laser Pointer Components
If you are interested in hobbyist projects like this but do not have a 3D printer, it is one of the best investments that you can make! In all honesty, the 3D printer I use is only 2 months old and already failing. Unlike the servo motors, don’t buy the 3D printer I use, invest in something better for yourself.
The software you can use to design your own 3D printed parts
There are lots of computer-aided design (CAD) programs out, and most of them cost lots of money. I choose to use FreeCAD, which is a free open-source program. Sometimes it misbehaves, but the occasional slight headache is worth its lack of a price tag. Feel free to check it out yourself!
Check Out and Download FreeCAD
Plenty of youtube videos gives excellent tutorials on using FreeCAD. While the program has a small learning curve, once you’re acquainted you’ll be able to design parts pretty quickly.
You’ll also need a slicer. A slicer is a program that takes 3D models that you design, in FreeCAD for example, and converts the model into tool instructions for the 3D printer, which is called gcode. Another great free and open-source slicer is Cura, which is easy to modify. Most 3D printers, such as mine, come with a Cura file to set up the program and generate gcode in a manner the 3D printer can handle.
The ALP Design
The ALP is designed to point a laser at any location. Two servo motors on two orthogonal axes allow for two degrees of freedom. I refer to these two angles of Azimuth (Az) and Elevation (El).
The servo motor at the bottom controls the azimuth of the laser pointer, and the servo motor on its side at the top controls the elevation. This is what creates the two degrees of freedom, and allows the ALP to point in any location… almost.
Each servo is limited out to only turn 180 degrees. Therefore, the ALP can point at everything that is in front of it. For my applications, that is totally fine. If I ever decide that I need full 360-degree rotations, I’ll just get different servos.
The Base of the ALP
The base of the ALP is designed to provide a flat stable surface with long extruding points. This keeps the ALP from tipping over while it is in motion. At the center of the base, walls extend upwards to hold the azimuth servo motor in place. A slot is made in one of the holes to ensure the wires are not obstructed.
Servo to Servo Adapter
To attach the azimuth servo motor to the elevation servo motor, another bracket was developed.
On the servo motor itself, a brass horned gear serves as the output shaft. The servo kit came with different interfaces to the brass horned gear. I choose to use the black circle shown in the image below.
The servo bracket I designed interfaces to the black circle with four screws provided in the servo kit. The servo to servo adapter has four small holes at its base to align with the black circle, and a larger circle in the center to avoid the black machine screw in the center.
The servo to servo adapter also contains two poles in which the elevation servo is suspended between. Metric size 4 bolts attach the elevation servo to the poles and keep vibrations to a minimum.
At the back of the adapted is a large hole that servo as a wire guide to prevent any wires from rubbing on the servo motor output shafts.
Laser Pointer Adapter
The laser pointer adapter provides brackets to mount the laser pointer and guide the wires away from the elevation servo motor shaft. The holes for each bracket should be 6.5mm in diameter.
Extra holes in the design are simply a result of two things:
- I didn’t want to use a lot of plastic so it would print quickly.
- I was bored and had some extra fun with it.
Similar to the servo to servo adapter, the laser pointer adapter interfaces via the same pattern onto the black circle that comes in the servo motor kit.
Download my 3D Models and .stl Meshes
Both the FreeCAD models and .stl meshes have been uploaded to Thingiverse and are available for download.
Download FreeCAD Models and .stl Meshes from Thingiverse
Like any other open-source project, the effort I put into this is all for free. If this guide or these resources have been helpful to you, and you have $5.00 spare, consider buying me a coffee at the link below. Thanks!
How did I do?
Give me some feedback! Let me know if you have any questions or comments, or if I just got something plain wrong. You can connect with me on my social media links.
If you found this guide extremely helpful, consider buying me a cup of coffee! I would appreciate it so much, and it’ll give me more energy to write guides like this!
