Cheap Simple Robots

Community General Discussions
1

Hi;

I am starting a Robotics and Computing club at my School and need some ideas for some cheap, simple robots that I can get the kids building.

The idea will be that they / their parents buy the materials based on info that I supply and I help them build there robots during the club (aprox 6 hours total).

I don't really want Maplins type toy looking robots and anything with a microntroller is hoing to be to expensive. The topic for the term is renewable energy and climate change so recycled robots may be on the cards?

I have though maybe something like a solar powered beam robot?

Anyone have any thoughts?

Many thanks

We (I) will also probably be building a club robot based on the Basic Stamp / Raspberry Pi (I already have these) or a PC.  

2

**There have been a number of robots that fit the **

junk/recycled bullet point you are talking about. Expensive is a relative concept. Clone arduino Nano’s from Chinese eBay sellers have gotten down to the $3 or $4 USD price range. Motors like what the Start Here Robot uses can be bought for a couple dollars each. Small, useful breadboards can be bought for a few dollars each. You can buy tcrt5000 IR emitter/detector pairs for line following/optical encoder reading for a few dollars for like 20. Add in motor drivers (L293/L298[boo]/SN754410/9110) for a dollar or two each for one or two channels per driver, a 4 or 6 cell AA battery pack, alkaline/rechargeable respectively, and I would imagine you could cobble a number of simple bots together for $20 or $30 each. I forgot bump switches/whiskers. Whiskers are fairly simple and inexpensive to build and add; you pass a length of curved/bent wire through a conductive ring/washer that is tied high or to ground and then maybe a resistor or the built in pull up on the arduino pin that is the input for the whisker. When the whisker hits something hard enough to touch the conductive ring, the input pin is pulled HIGH/LOW. You may need to add some software to debounce the inexpensive setup, but, software can be less expensive than hardware, sometimes.

3

Thanks for all the replies -

Thanks for all the replies - very helpful

4

I found this ATMeg328 on

I found this ATMeg328 on eBay UK, is this the kind of Arduino Nano that you are talking about birdman? and can these be used to control a Robot? If so these are brilliantly cheap. What programming language do they use? 

5

AFRON

You might want to check out this site. Their aim is for educational robots for under $10.

http://robotics-africa.org/

6

I would have the club

I would have the club provide a simple inexpensive and expandable robot kit that they sell to the members. I like this one for the chassis (it was one of the one’s ossipie’s choices).

Another choice is the Dagu Magician chassis for around $15. I got mine from SparkFun, plus about $10 for the encoders.

It would probably be best to have a single controller supported by the club for the beginners at least. My favorite is the Teensy 3.1. It's $20, but it's about the size of an Arduino Nano, is programmed from the Arduino IDE with a simple extension to the IDE. It has a large amount of pins, but to access some of them you need to put headers on the top. The Teensy 3.1 is running an ARM Cortex-M4, with 256k flash and 64k of RAM. There are built in level shifters so you don't have to worry about your voltage mostly.

Another choice for the controller is a Raspberry Pi for around $35-$40.

I'd return to eBay for sensors and motor controllers. There are SRF-04s for a couple dollars per and lots of other things you can make IR distance sensors from.

Unfortunately the cost can add up quickly, so I won't suggest that robotshop.com has the Hokuyu laser rangefinders.

If, in addition to the money that each member brings in through dues or an initial purchase of their bot, the club might get some money of its own to buy some more expensive items like tools and solder and some basic components. And don't forget a few GPS units and other interesting sensors that individuals might not be able to afford but the club could loan them for a while to a member with a good idea.

It takes imagination and discipline to make robots on the cheap. I like using 8020 aluminum extrusions for the skeletons of my larger bots and OpenBeam for the smaller ones. These don't seem cheap at first, but you can use them to avoid welding.

Another extremely useful tool is a 3d printer. Print your own chassis design if you have design skills and imagination. Even if you don't want to print the entire thing you can still print the connectors and joiners. I'm hoping to be able to print motor mounts for Bilbo (an unknown Marx brother) because I don't have metal working tools and the motors were from eBay with non-standard mounting points.

If you can and know what you're looking for, search for motors everywhere. Garage sales and eBay and Craigslist and Goodwill and suchwhat are wonderful places to spend time.

Have a nice day, and happy building!

7

I forgot to suggest

a chassis with motors for cheap could be found at second hand stores in the form of discarded rc cars. Remove the RC board, add a controller and motor driver, and an obstacle avoidance sensor. You could have a fleet of 'bots for about $10 or $15 USD.

8

Banggood.com and aliexpress

Banggood.com and aliexpress are other good sites for ready use cheap boards. I’ve even seen a GPS board for 12dollars. Both places offer bulk discounts, so build a mini swarm for under 10 it’s feasible (arduino nano clone+driver board dual motor+2gearbox motors+2wheels+4AA nimh+battery holder+ hc-sr04), then i’d like to add a hc05 bluetooth to serial to add app controlling.

A power drill it’s really useful to make holes for the screws, untwist cat5 cables(my favourite source for jumpers), make holes in bottle caps to make wheels or just make the chassis lighter. Also a caliper it’s so useful!

9

Well, I just replied

Well, I just replied another post of yours with some links to possible candidates for a workshop.