March 2007 update: see below for a relative of Spitter
What can I say? This hungry little fellow is a picky eater. He is very hungry. If you don't feed him often, he asks for food. Clearly, the most appropriate food for him is paper pellets. But whenever I feed him, he objects and spits it out.
|Spitter and his food||He's hungry: you must feed him|
|But when he senses the food in his mounth, he gets upset and his wheels start spinning||He tries to swallow (you can see the throat openning), but then spits his food|
If you are looking for a bot with a strong personality, you have found your match.
More seriously, I built it to demonstrate the NXT to students and colleagues. I felt that a rude robot would be more memorable than a polite one. That meant one thing: throwing paper pellets at them. Throwing something that was either dangerous or valuable was out of the question, but paper pellets are fine. For the Lego purists: you can make even the pellets from genuine Lego, but you'll have to sacrifice a few instruction booklets...
I wanted it to be compact, which ruled out using large trebuchet or a catapult. When searching for Lego robots that throw things, I found Philo's amazing Hammerhead. I used the same throwing principle, but a different feeding mechanism. It detects the white pellets using the light sensor (this is why the throat area is completely black, to make the pellets easily visible. Once it sees a pellet in its mouth, it starts spinning the wheels, waits for them to spin fast, and then opens his throat. The pellet falls into the spinning wheels and gets thrown out.
Spitter is very reliable, even though the pellets are not identical. If you feed him more than one pellet, they usually all get ejected. A two-year old niece tested it very thoroughly. Most of the time, he did not disappoint her. (My kids are older, so they got bored more quickly than her.)
Here are a few more pictures of the construction.
|Front view||Side view|
|The other side, with a closed throat||and with an open throat|
|The back side||The underside|
Thomas Midtskog built a variant of
and sent me this
description and picture:
© 2006, Sivan Toledo