Imagination Rules

Imagine a robot capable of being thrown into the air, and no matter which side it lands on it,
it can cushion its fall with its legs, and immediately return to attack.

No self-righting needed: it's always right.

Imagine a robot that can look like a beetle or a War of the Worlds Martian, with an attitude
to match.

Imagine a robot that can change its direction of travel and the way it "looks" in half a second.

Imagine a robot that can lift itself over a metre into the air, and stay there.

Imagine a robot with a seriously deranged attitude to those beneath it.

Imagine a robot that can turn its legs into drills.

Imagine a robot that can span a clear space of 2.3 metres in width and length,
and still have the means to stomp on things beneath it.

Imagine the look of fear and trepidation on other roboteers faces in having to deal with this
monster.

Imagine what this robot would be able to do to a fluffy bunny rabbit.
... and let that picture help you keep well clear of its legs!

Rules & Regulations

up to 200kg. Feb 2 2001. COOOOOL!!!

Design Sections

An outline of the components follows, here, along with an assessement and evaluation of different options. In order to minimise embarrassment and also to deceive myself such that I am not put off from going ahead, actual costs have been excluded. Relative pricing, and the most cost effective options *are* used to assess what to use.

It's the usual engineering story, basically. Come up with the goods, then work out how much it costs, and *then* find out alternative, cheaper solutions, where possible...

Stress!	Section outlining engineering stresses, and calculations necessary to prove reliability!
Comms	Communications section, between robot and control computer.
Control	Section describing how control of robot is managed. Includes embedded processor and main PC.
Legs	Design and specification of legs.
Gears	Specification of gears, appropriate gear ratios and helix ratios.
Frame	Brief details on frame.
Controllers	Motor Controllers. Analysis of options - assessment of weights, sizes, price and performance.
Batteries	Battery options. Weights, and calculation of power needed for time available.
Motors	Monster motors and littler motors, and on how one of them simply out-does the rest.
Armour	Armour-plating. Steel, Lexan, Titanium. Haven't included Aluminium, yet.
Feedback	Sensor input for legs and the SpiderBall body, to determine extension and rotation.
Challenges	How to break SpiderBall. How SpiderBall mashes other Robots.

Formulae

Useful formulae necessary for engineering calculations. Kept here until another location is found for them!

Area of pentagon = apotherm * radius * 5 / 2

Lifting capability (N) per motor = Torque (Nm) * GearRatio / LegRadius * GearHelixRatio

Leg travel speed (m/s) = Motor (RPM) / 60 (sec/min) / (Gear Ratio * Leg-Helix-Ratio ) *
                         PI * Leg-Diameter (mm) / 1000 (mm/M)

Power (Watts) = Wheel (RPsec) * PI * 2 * Torque (Nm)

SpiderBall Weight Assessement

For a 70cm bot:

	utter monster.  space good enough to place larger controllers...
	hmm... probably don't have to mess about with cramped spaces.
	means better maintenance.

	using CDFRs means that there's 6 spaces in which the 6
	Hawker batteries can go... without attempting to cram
	things in.

 	... but CDFRs work out at about twice the cost of NCC-70s,
	but might be worth it for the space saving.

	12of OSMC3-2 is same weight as 6of CDFRs.

For a 50cm bot:

	50cm diameter: minus appx 15cm clearance in middle
	equals 17cm space for motors.  minus space for framework,
	probably drops to 15cm for motors.

	yeeks!  _really_ close

	hmmm... gear arrangement sideways?

Might have to rethink the 70cm size. May have to go down to 65cm to a) reduce the weight b) still be able to fit everything c) not be so small as to be vulnerable.

I'd love to be able to do a tiny 50cm bot, however it's going to be possible for robots with claws, such as Razor, to get round that and crush it. The whole point of the 70cm bot is that that isn't possible. Yet...