In theory making a robotic device based around an Arduino or other platform is very easy, as the wiring and electronics isn't that difficult. However unless you are quite mechanically-capable building the actual robot or other framework will involve a lot of work. But if you have a construction set such as Meccano, Makerbeam or LEGO you can get making very quickly. This is demonstrated in the following project by Instructables user "enjoying electronics" who makes a spider based around Arduino and Fischertechnik construction pieces. The spider has eight servos and four legs, each individually-controlled which allows a degree of movement and a type of walking - for example:
Not bad at all, and a great framework for other motorised devices. For detailed instructions head over to the project page. And for more, we're on twitter and Google+, so follow us for news and product updates as well.
When making your own robotic spiders or devices that could use a smaller Arduino-compatible board - consider the LeoStick. It's the Arduino Leonardo-compatible board that's cheaper and smaller than the original:
Apart from being one of the smallest Arduino-compatibles on the market with USB, it also has an onboard RGB LED and piezo which can be used a knock sensor and various tune and sound effects. Plus you can add extra circuitry with the matching protostick! For more information and to order, click here.