Well, if others getting better results perhaps it is only us. I'll
answer your questions in case you have any more thoughts-
Each decision that the kids make in their robot
design matters. Using the "knob wheel" as a drive gear would be a bad idea for
precision, while most of the "normal" gears work quite well.
We're using the gears
that the machine came with (the whilte and orange ones) and didn't create
any gear boxes ourselves. (that made it into the final robotic
What kind of tires are they using? Are they
rigid or bendable?
We're using the 8.2 cm tires, the big ones, because
the inch to .1 rotation is 1 inch and a breeze to figure out when quickly
updating the robot. Because we're using rotations and not distance or
time, that should increase our precision. Should.
Are they using
crawler tracks? Nope.
What kind of gear ratios are they
using? 1"=.1 roation
Are they using programming techniques
that depend on consistent battery voltage?
Not to my knowledge.
We're programming it to go straight certain distances then turn, then go
back or forward, and turn again. Not complicated stuff.
Is their chassis rigid or highly flexible?
rigid. We have noticed that becasue of the length and position of the
back wheels, sometimes they can squeeze together slightly and I try to
remind the kids to open them up before sending it out. But altogether, it
should resemble a hard chassis.
Is the weight of the robot over
the drive wheels or offset?
They fixed this by adding a counter
weight during the 5th week and taking off a side mounted gear.
It was a hard decision and limited what missions the kids could do, but
ultimately it did lead to slightly higher, but not perfected consistency.
Is the weight unevenly distributed? All the rules of physics
apply and everything affects the outcome.
I can only say it's better and
it was, so perhaps it's still the main issue. I had asked a while ago if
anyone knew of any programs or books that would help with robotic design to
counter some of these problems, and ultimately I purchased a book to help me
understand the basic designs better and their pros and cons, but if you're
not having the same problems, then it MUST be our design. :( Hope
we'll figure it out after the competition. We're looking forward to
seeing what all the other robots look like :)
Or that the spinning back wheel of
the classic "tribot" design can alter the the direction of the robot as it
swings around when you start to back up.
This design was abandoned in the
3rd week for a much more stable design that wasn't as twitchy.
Then have them ask the robot designers of
that team "How did you get your robot to be so consistent? What did
you learn about inconsistency? Did you use any special parts that
helped (e.g. different wheels)?" The answers will mean so much
more to the kids coming from other kids rather than from a book or
coach, and they might get more excited about competing next year with
their new-found knowledge.
I will ask them to write down their
observations. ( I know at least two or three of them will find this
the best part of the competition.)
I always tell my kids that their goal is to
have each mission work 9 out of 10 times. Their tendency is to try an
idea once and if it doesn't work to fiddle with it. How do they know
if that wasn't the 1-in-10 failure and that the next 9 times it would have
worked great, unless they tried it multiple times? So even learning
good engineering "process" is something that produces consistency in the
They have been keeping a log to track data and the rule I asked
them to follow was no adaptations to the program until they had seen it run
3X in a row. Then fix it if it's still wrong.
I hope your team can turn your frustration
into a quest for more knowledge and understanding. After all, that's
what makes a great engineer!
Yes. We are upbeat about all they have
accomplished- the programming, research, teamwork. I am as sunny as a
summer day when it comes to what they have accomplished and at the meetings,
but afterward, I'm disappointed I couldn't lead them to better
answers. Not give them answers, that's worthless, but even send them
in the right direction to look around. The pitfalls I knew about, I
had lesson plans that taught about it and had them experimenting to figure
out the concept. It was great, but I clearly am lacking on the design
side :( It will be fascinating to me to see one that works better than