Cover image for SMARS

SMARS is the Screwless, Modular, Assemble-able, Robotic System.

What is SMARS?

SMARS - the friendly little robot you can print yourself, and learn to code.

SMARS stands for Screwed/Screwless Modular Assembleable Robotic System. It has an ultrasonic range finder a the front (it looks like the robots eyes), and can use this to detect obstacles and then move around them. It has 2 motors, which enable the robot to move forwards, backwards and turn left and right. The wheels have mechanical tank tracks, providing excellent grip on most surfaces indoors or outdoors. SMARS is powered by a 9 volt battery, and can be swapped out if it runs out of power. The Arduino provides the brains of the robot, with simple programs uploaded via a USB cable to the robot. The motors and Arduino are powered via a motor-sheild (a sheild is a circuit board that connects on top of an Arduino via the header pins), the motor shield may also have a buzzer and bluetooth connectivity depending on which model you buy (We’d recommend the Fundumoto motorsheild).

On the thingiverse SMARS page Kevin Thomas describes SMARS as:

SMARS outline

“a simple robot designed to the educational field. The main features of SMARS are the reduced number of components, the possibility of mount it without screws and without soldering any part, it doesn’t need glue or similar and it’s really cheap to build. Another main point of SMARS is the modular design. You can mount different sensors and tools and design your own parts.”

– Kevin Thomas, Creator of SMARS Thingiverse

What you’ll need to build a SMARS robot

To build a SMARS robot you’ll need a couple of things:

We’ll dive deeper into each of these areas below.

Electronic Components

SMARS typically uses an Arduino paired with some small 150 RPM motors, a motor sheild and an Ultrasonic range finder sensor. SMARS can be 3d printed in PLA or ABS, with the option of TPU based caterpillar tracks.

Bill of Materials (BOM)

Item Description Qty Cost
Arduino Arduino Uno R3 1 1 £24.00
150 RPM motors N20 150RPM Micro Metal Motors with Gearbox 2 £9.00
Motor sheild Fundumoto Arduino Shield1 1 £12.00
HC-SR04 Ultrasonic range finder sensor1 1 £2.50
9v Battery a 9V Battery 1 £3.00
Dupont cables Dupont cables (male-to-female) 4 £1.00

There are newer versions of the SMARS robot available, this BOM is for the original (and simplest) version of the SMARS robot.

3D Printed Parts / STL Files

SMARS consists of 7 parts:

  1. chassis.stl - the main body, print 2x of these
  2. unpowered_wheels.stl - the unpowered wheels, print 2x of these
  3. powered_wheels.stl - the wheels that are connected to the motors
  4. motor_holder.stl - holds the battery in place, print 2x of these
  5. range_finder_holder.stl - holds the ultrasonic range finder
  6. range_finder_cover.stl - slots on front of the range finder holder and protects the sensor
  7. track.stl - the machanical track goes over the wheels and forms a caterpillar track. Use 3D printing filament to connect each peice

Print out each peice, noting if multiple parts need to be printed. The parts will need support structure priting, so be sure to enable that in your 3D slicing software.

Program code

SMARS is powered by the Arduino Uno, which as an 8bit processor is typically programmed in C++ using the Arduino IDE which you can download for free (for Mac, Linux and Windows computers - there is also a web-version for Chromebooks available from the same link).

To get you started with programming SMARS, take a look at the code below:

Assembling your SMARS robot

Learn how to download, print, assemble, and program your SMARS robot with this easy to follow (and free) course

Taking it further

Once you’ve constructed your SMARS and you may want to learn what else you can do with SMARS; you’re in luck - there is an entire YouTube series created just for this purpose

  1. Note, cheaper clone parts are available at 10% of the price  2 3

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