Ogre - a LEGO NXT based "tank"

OK, it was pointed out to me that I hadn't actually announced this on LUGNET,
so... Ogre is the logical (or perhaps I should say "obsessive") conclusion to a
series of Zamor shooting robots I've played with for a while. The launching
system fires about 9+ spheres per second at about 4 m/s, and the ammo magazine
holds about 50 spheres (without jamming too often). I started out trying to hold
off using NXT motors (at first I wanted a pan and tilt turret, but ended up with
a fixed main battery), so I used PF motors. This has the nice side benefit of
making the tank "automatically" and RC vehicle; just don't turn the NXT on, and
the entire thing works very well under RC control from two stock PF remotes
(mated side-to-side, with one upside down; the inverted one you pull back on a
toggle to fire, while the upright one controls the two treads). The upper bogies
in the treads are sprung with shocks to keep the large tread systems under a
fairly constant tension, and as a bonus it has a little mini "spy cam" on one
side.

The NXT can control the unit fairly well - actually, better than I can with the
remote. By using the Hitechnic IRLink, the NXT control can use PWM on the PF
motors, resulting in much smoother control for turns and variable speeds. In
contrast, a human behind the controls tends to look jerky and inexperienced. It
is a lot of fun just to play around (we'll be finding Zamor spheres in the
living room for the next decade I suspect), but it's wonderful to watch it "Take
out" at target autonomously. No BS Gallery as yet, but here's a YT video:

http://www.youtube.com/watch?v=DNHGaSagaM4

Yes, LEGO doesn't make tanks. But thank goodness all the pieces are there for
the rest of us. Stormtroopers, beware!

--
Brian Davis