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From: jaeger@sunrayce.solar.umn.edu (Charles A. Jaeger)
Subject: Just finished building Jones/Flynn's Tutebot
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Date: Thu, 30 Dec 1993 21:32:08 GMT
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For those of you who have considered building a small robot on your
own in your spare time, I would highly suggest you get the book --
"MOBILE ROBOTS : INSPIRATIONS TO IMPLEMENTATION / JOSEPH L. JONES,
 ANITA M. FLYNN. ISBN 1-56881-011-3"

I finished building the Tutebot (A Tutorial Robot) as described on 
pages 11-36 and got the little beasty working with less than 20 hours
of work.  The cost to me was about $40 in parts from Radio Shack,
about $30 for two contact switches and an additional motor from Lego Inc.
(can you say 'overpriced':(  ) and many many scrounged parts from my brothers
Lego-Technic collection.

General performance comments--
- My 9 year old nephew said it was his greatest christmas present ever.
- Forward speed is about 25cm / sec
- Geartrain reduced shaft speed by 27:1
- Lego construction allowed for quick fixes (which were required quite 
    frequently) since the frame has an inherent short lifetime.
- Front bumper using contact switches holds up exceedingly well.
- The potentiometers and capacitors don't hold up to much side impact
    force on the breadboard so they are a common failure point.
- Experiment on an extra potentiometer to test other methods of mounting. 
  (I toyed around with a necessary one and had to buy another!)
- Forget mounting the power switch on the breadboard.  Get a chisel and 
    a drill and mount it through one of the pegholes on the breadboard.
- The center of gravity tended to be too close to the front axle.  This 
    causes the robot to tip forward on sudden stops and reverses.  One 
    quick fix is to mount the batteries closer to the rear caster type wheel.
- Battery life: Depends on too many variables to talk about.  I would suggest
    you use 4 C rechargeable nicads since they will probably be more cost
    efficient in the long run.
--
Charles A. Jaeger, B.S. CpE          612/890-5660 or 612/890-5696
Computer Engineer                    jaeger@sunrayce.solar.umn.edu
Burnsville, MN                       cjaeger@gellersen.valpo.edu
