18 Jun 2003 (updated 18 Jun 2003 at 22:29 UTC)
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First Entry
Hey, this is my first entry into my diary.
Currently I
am
working on my new multipurpose robot. It will be the Little
Green Machine Two.
The original Little Green Machine was disassembled
after it
suffered many design flaws. I thought I would go through
those failures, and explain some things I picked up along
the way.
First off, it turns out that modified servo motors
aren't
as good as some people say they are, especially under
constant running (they are really only suited for a very
light robot that won't being running for a while at a
time). As they get hot, the RC circuit inside is
thrown off, and the timing gets messed up. This means that
if you calibrated the motors to have stop in the middle,
they will actually rotate when you think they are stopped.
Go for broke and buy gear motors with encoders, that is
what I am doing for the new robot.
The other problem I had was suspension. The old
robot
didn't have any and would often get hung up, the new one
has suspension on the casters. I am using those little RC
air shocks - they are slightly expensive but are smoother
than coil springs - and look really cool.
The new robot also has a more powerful, more
reliable
controller. I was using a Dios - kindof like a basic stamp
only bigger, faster and cheaper - from Kronos Robotics
(www.kronosrobotics.com) and although I did love the chip,
I have to upgrade. The chips are a great learning tool, but
I want a C compiler.
Anyways, thats my motivation for designing the new
robot
and a little bit about the old one. I will post more
details as I go along. Right now I am working on getting
AVR-GCC customized and ready to go and designing the
boards - then its on to making a bootloader and designing
the motor controller.