If I had to second guess what the team that designed the tread section 40 years ago were intending
I would have to guess like this: The Robot was never meant to go outside the Jupiter 2. The treads would have too many problems
if they were used outside in the dirt and sand and rocks. But it might not have been so bad on the smooth floor inside the
spaceship. Remember, per the story line, the human crew were supposed to spend the trip in suspended animation. Maybe the
designers/writers figured that the Robot would take care of things while everyone was asleep. Of course I could be all wrong,
the Robot and Dr Smith were last minute additions.
First problem:
2 feet. In the first few episodes the robot does "walk" by moving its feet. It just shuffles along. Very slowly. So slowly
that it never walks again, the feet were then bolted together. A good move. But even today construction plans still call for
two separate feet. A bad move. Forget about it, build the tread section as one part. This is cheaper, easier, and will give
lots more room in the single tread section for motors and batteries.
Second problem:
Treads. It is very difficult to navigate and maneuver a machine with treads. I don't care what you see on TV, it does not
work well. Really the only time treads work is when they are on dirt, then the friction is low and most of the time accurate,
pin point navigation is not needed. When you parallel park your M1 Abrams tank
and can't quite get it 6" from the curb (if there is any curb left after your attempts) you may get a parking ticket. Of course
the ticket cop may have trouble reaching the windshield wiper to put the ticket under…
Third problem:
There are actually 4 treads, two wide and two narrow. If the feet are not bolted together it would be quite a task to run
(power) different width treads on a non solid surface, the narrow tread would tend to dig into sand/dirt more then the wide
tread. And if the feet were bolted together there would be serious traction problems operating on a non-flat surface.
I am not saying
that treads are impossible to make work. But I am saying that it will take a huge effort to make work. Treads must be made
of a material that is reinforced and not going to stretch. It is possible to have such treads manufactured but it will be
very expensive, probably 5 or 10 times what treads now cost.
Wheels must
also be designed so that they guide the treads such that they do not fall off the wheels. Probably
some sort of spring loaded system will be necessary to maintain tension in the treads. Just more complexity.
And in the
real world it is necessary to work near and around objects. It is necessary to not bang into walls and not run over human
feet. So why not treads?
Its because
treads will fight each other during a turn. If there is different frictional forces at each tread the center of rotation of
the turn will not be predictable and there will be no way to steer accurately, your 300 lb Robot will roll over your wife’s
foot and you will have to take a quick trip to urgent care.
And remember,
the standard plans are not and never were intended to use any sort of motorised system.
But build a B9 robot without
treads? No, not possible.
Build a B9 with treads that
can be steered accurately? Yes!
