Round-up of coasterbots from around the internet

Round-up of coasterbots from around the internet


We’re nearing the end of the design phase of the Make: Robot Build, have you started to draw up plans for your bot? If not, here are some examples of designs we’ve found around the web, for your amusement, edification, and design inspiration. Have a different idea about what to make? Join in the robot build discussion over on the MAKE Forum and let us know about it!



Isotope, of Let’s Make Robots, built this amazing fridge-climbing LadyBugBot. Using a CD as a base, and sporting a papier-mâché cover, it uses two motors with wheels to drive around, except there’s a catch: instead of moving across the floor, it uses a set of magnets to stick to his fridge, and drives up and down instead of forwards and backwards. He also designed a combination bump/depth sensor, to sense if the robot is in danger of running into something or off the edge of the fridge.

LadyBugBot by Isotope
Chassis: CD
Power System: 3x AAA battery, solar cell
Actuators / Drive Train: 2x continuous rotation servo, small wheels, magnets
Controllers: picaxe 08M
Sensors: tilt switch, 2x handmade bump/cavity sensor
Outer Shell/Casing: paper mâché ladybug body
Notable Feature: Climbs on walls!

CD Bot


The CD Bot by Iain Craig is a good example of a practical design built with simple components. Rather than avoiding obstacles, it seeks light, using the output from two light dependent resistors (LDRs). The base is constructed from two CDs that have been glued together, with cutouts for the two wheels so that they don’t protrude from the body. This helps to reduce the chance that they will get snagged on something as the bot moves around.

CD Bot by Ian Craig
Chassis: CD, with slots cut out for the wheels
Power System: 3.6V NICAD battery
Actuators / Drive Train: 2x DC motor, small wheels
Controllers: picaxe 08M
Sensors: 2x LDR light sensor
Notable Feature: Simple construction



Lets Make Robots user D Rudolph built this 812-R3 robot using 3.5″ CDs and a bottle cap. The first CD was used as a base, then two quarter-CD parts were used as supports for the servo motors. The final CDs were used as wheels. It is a good example of an extreme commitment to disc-only design.

812-R3 by D Rudolph
Chassis: 1.5 CDs
Power System: 4xAA battery
Actuators / Drive Train: 2x continuous rotation servo, CDs for wheels, bottle cap casters
Controllers: Arduino
Sensors: 2x bump switch
Notable Feature: Frame built entirely from CDs



The original version of Bill Sherman’s self-balancing robot, BaliBot, didn’t use CDs, but when he found that it needed larger wheels, he wised up and included them in the final design. It stands out from the crowd (literally) by including an active control system, which allows it to balance on the two wheels without need of casters.

BaliBot by Bill Sherman
Chassis: Aluminum frame
Power System: 4x AA battery
Actuators / Drive Train: 2x continuous rotation servo, CDs and foam for wheels
Controllers: PIC 16F876 microcontroller (using PIC Basic Pro)
Sensors: 2x IR distance sensor
Notable Feature: Active balancing system eliminates the need for casters



The CDBot by Angus Thomson appears to be quite a sensitive robot. It’s an older design, based around a Motorola HC11 microcontroller that was programmed in assembler, but is a good example of packing a large number of sensor peripherals into a traditional stacked CD design. Unfortunately, the project webpage appears to have disappeared.

CDBot by Angus Thomson
Chassis: Stack of 3 CDs
Power System: Unknown!
Actuators / Drive Train: 2x continuous rotation servo, medium wheels
Controllers: Motorola HC11
Sensors: 2 LDR light sensor, 3x bump switch, 2x IR proximity detector, 3x IR reflective sensor, 1x pyroelectric sensor, 1 Sharp IR range finder
Notable Feature: Impressive number of sensors

CD Cart


Let’s Make Robots user TheOther1 built this obstacle-avoiding CD Cart using a single CD as a base, pager motors for the drive system, and an IR distance sensor to perform collision avoidance. Rather than using a caster to level the base, the back itself is used as a sort of caster, leaving the robot at a permanent angle. Special care has to be taken when programming the robot to move, because any sudden stops can cause it to tip forward. Is it an elegant design? No, but it wins points for simplicity, and the builder claims that it was built using only parts that they had lying around their house.

CD Cart by TheOther1
Chassis: CD
Power System: 9V battery
Actuators / Drive Train: Tiny geared pager motor, wheels, servo to turn IR sensor
Controllers: Arduino Decimila
Sensors: harp 1x IR distance sensor
Notable Feature: Perhaps the simplest drive system that could work

And here are some more bots to check out:

Want to keep up with the Robot Build? Here’s a handy checklist:

Robot Build Contest Landing Page
MAKE Flickr Pool (tag all images “coasterbot”)

MAKE Forums Robot Build Discussion
Jameco Robot Parts Bundle (not required to participate in contest)
Read back issues of the Robot Build Dispatch Newsletter:

Discuss this article with the rest of the community on our Discord server!


Ready to dive into the realm of hands-on innovation? This collection serves as your passport to an exhilarating journey of cutting-edge tinkering and technological marvels, encompassing 15 indispensable books tailored for budding creators.