Let's Make Robots!


Win penthatlons
First design1.04 MB
Second design972.65 KB
Motor controller903.56 KB
Power supply849.01 KB
IR sensor 1837.13 KB
IR sensor 2762.73 KB
Gripper cogs909.47 KB

Just fixed some URLs to images, no real updates, this bloke has been disassembled for ages.

This is my entry for the 2011 Swedish National Robitcs Championship. It finished on a shared last place, since my code was written for dark lines on a light surface and I forgot to change parts of it :(

As you can see I've built the chassis from entirely from Meccano. This is because I happen to have quite alot of it. It's a great building material.

The CPU I've decided to use is the Arduino Uno. I just hope I won't run out of digital pins All digital pins are in use, just four more analogs left I ended up using all pins but two

It has a dumpster-style arm that goes down and holds the object, so it can drag it.

He sees with a Sharp GP2Y0D805Z0F Digital Distance Sensor 5cm and five QTR-1RC.

The TAMIYA gearbox is powered by two Brushed DC Motor: 130-Size, 6V, 11.5kRPM, 800mA Stall.

The first design looked like this.


First design

It had some problems, mainly there was too much belt in contact with the floor causing it to turn like crap.

The second design looked like this.

Second design

I needed more space so I redid the design(again) and ended up with the picture you see at the top, more space and just better turning capabilities.

Here's a picture of the motor controller, it uses an L239D.

Motor contrller

Image of the power supply before I broke out it from the veroboard.

Power supply


Here's an image of the backside of my linesensors:

Line sensor cables


Picture of K.L.A.S at the terrain track, failing horribly because he lost his left track(which didn't make his turning capabilities any better)


Here's the third design.

I'll be uploading videos later.

Update: 2011-01-24

Wohoo! IR-sensors mounted in the front, pictures coming in the morning

Update 2011-01-28

IR sensor pictures.

IR sensor 1

From the side.


IR sensor 2

Upside down.

2011-01-29 Gripper cogs

Cogs! Finally found some I can use. I found them in two old CDROM drives I had lying around. The drives have at least five years between them, come from different brands and one is a DVD burner and the other one is just a CDROM reader. Imagine my joy when I realized they used identical designs for sliding the tray in and out :)


2011-02-03 Motor controller

Although I built a nice little L239D-based motor controller I've decided to go with Pololus  Pololu Qik 2s9v1 Dual Serial Motor Controller instead of my home made one. It saves me some pins and will hopefully save me the work of writing a library to talk to the L239D.


Object avoidance is sort of working.


Object avoidance is finished(for now), linefollowing is at a basic stage, I need to rebuild the linefollow-array first, since two of them broke, 5x QTR-1RC should be at my doorstep in the next few days. Oh, new picture too.



The arm has been mounted!
Image of K.L.A.S next to my laptop in the workshop at RobotSM


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But where did you get the figure 3amps? I found 2.1 amps on the pololu website at which it still generates some heat and carnage on hardware.

What functions will it perform in the robotics competition?

From what I've read they can generate up to 3A in stall. 2.1 is still too much though, but thanks for correcting me.

It's a five part competition consisting of line following, maze solving, a terrain track, collecting soda cans and placing them in a specified area and "show off"; which is just what it sounds like, try to impress judges and such.

Now I know where I got that figure from :) 2.1A is when running them at 3V. I run mine at about 6V, I think I did some calculations to come up with that number, not sure though, this was at least a month ago:)

thinking of trying the substitute motors. The tank chassis should go well in the terrain section. Good luck in the comp and keep us posted.

Yes, I sure will. I have a weeks vacation coming up soon and I'm planning to devote most of my time to get the bot up and running :)

Hey there, I also had some problems with the motors the Tamiya gearbox comes with by default.  They are pretty darned noisy electromagnetically and would cause problems throughout the electrical system in my robot, particularly with sensor readings.  Sometimes I would even get unintended Arduino resets.  I fixed the problem mostly by twisting the power lines to the motors and adding capacitors.

Just curious, have you had issues with the rubber Tamiya tracks coming off during turns?  I tried a bunch of different configurations and the tracks would always slip off the idler wheels for me.

Yeah. I had huge problems with the TAMIYA motors. They caused my arduino to do all manner of strange things, equally the L239D :)

It's strange. I seem to be the only person who hadn't had the notorious track-slipoff issue. I think you have to remember no to have too much "free" track, that's where it'll slip. That's why my design have the big wheels for support in the middle.