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So here's the world famous pink and green lawn mower. Pink for these wheels
(this thing started out life as a Barbie Jeep) and green for this battery
(doesn't use any gas). It's, uh, got little bumpers. I'll show you how those things work. It's got little
flaps, coated with aluminum so that when they touch, the mower knows it'*** something.
It's got a little control system -- a *really* little control system: couple of NAND gates,
couple of timers, some relays, stuff like that. And that's the basic mower that just
responds to the bumpers and the flaps.
But it's also got -- I don't know if you can see it -- some coils down here that listen
to my electronic dog fence, and a circuit I got off the internet that reads those guys,
and treats them just like the bumpers or the flaps, so whenever it hits something it goes
in the other direction, until it hits something and then it goes in the other direction.
So...
Let me turn it over, and take a look at the cutters. There's three motors with little
plastic wheels [disks] on them, little razor blades attached to the wheels [disks], and
that's it for the cutting.
There you can see the...what I salvaged from the Barbie Jeep, the motors and the wheels
and the chassis.
It's got an independent suspension, so it doesn't get hung up too much. Here I'll show
you how that works. I don't know if you can see it. Anyway, without this it gets stuck
all the time.
So, that's, that's the mower. Let me plug it in [connect it to the battery] and turn
it on.
Oh, and one more thing I didn't show you...the steering. Steering is mostly random; it's
not controlled. But there is this little scrubber here, so that when the mower's going forwards,
it tries to turn the wheel to the right; When the mower's going backwards, it tries to turn
the wheel to the left, so it doesn't go back and forth over the same path all the time.
All right let me turn it on.
[Music: "Guinea Pig's Quest"]
[Music: "Waltz of the Toddlers"]
Oh, it runs like this for about an hour. Maybe an hour and a half. Gets most of the grass
in this yard. But, you know, it leaves a little bit. I don't care about that. Eventually it
gets it all. This yard hasn't been cut by anything else for about a year, so you can
see eventually it gets it all. But it doesn't get the edges at all. You gotta do that with
a lawn mower. I'm not going to worry about that