An Unbreakable Robot

Every self respecting robot must be tough and reliable.
We added another "must" to our design philosophy, and that was resilience

The Concise Oxford Dictionary defines 'resilient' as :
'Recoiling, springing back; resuming original form after stretching, bending etc. ...'

Every part of our robot that was even slightly fragile would be fitted with resilience in mind.
Better that it bends a bit in battle, rather than break.

The Baseboard
Charlie began this theme of resilient materials by choosing MDF for the base board. MDF stands for 'Medium Density Fibreboard' and it is tough and light and easy to work with, and yes, it's resilient too.

The base of our robot

 Here's the base of Slippery Strana, already well populated. Beautifully engineered, you must agree!

That giant ball bearing is a tough conveyor-belt component and gives Slippery Strana the freedom to spin on the spot and zoom in either direction on a whim. A bit noisy though.

The black angle-iron you see folded around the edge took hours to cut and bend, and was an ideal place to weld our 'mark 1' spikes. Sadly though, the spikes fell off one by one in our field trials and as you can read elsewhere, we even had to remove the hard earned rim to stay within our weight limit.

(Click the picture for a bigger view)

The Motor Bodies
The motors and gearboxes were still fixed within their Bosch drill bodies and we knew they'd have to withstand some hammering.

We pressed them into foam rubber (foam plastic really). Then, to fix them securely - but not too securely - while still allowing us to get at them for battle-damage-repairs, we tied them in place with carefully placed Jubilee Clips.

OK, they wobbled a tiny bit, but always wobbled back into line, where they should be.

(Click the picture for a bigger view)

The innards

Click for a bigger picture

The Wiring
All our wires were at least moderately well laced up, but again, not too tightly. If you click for the bigger picture, you'll see we used cable ties to fix down the fragile parts with 'limited elasticity'.

The little red button just left of centre is the reversing switch. It operated the sturdy relay behind it and the relay did the actual voltage reversal. Using the same servo arm to squeeze the trigger and to reverse the motors guaranteed that the motors were at 'stop' before the voltage was reversed. This made more demands on Charlie's remote control dexterity but we think it extended the life of the motors and triggers.

(Click the picture for a bigger view)

The Axles
Our axles were really just 'M12' sized steel bolts, cut to length and with the threads removed only where the bolt entered the drill chuck.

After tests with the Bosch drill bodies taking all the weight and pounding from the wheels, we guessed they wouldn't survive a battle without extra support. So we fitted a sealed-lubricant pillow block bearing to each side, after re-grinding two new longer 'axles'. The M12 bolts were a perfect fit.

You can see our bearing between the chuck and the wheel in the lower photo.

The Bearing Services Limited shop in Bath were very helpful and patient as we made enquiry after enquiry, trying to find exactly the right bearing.

Example pillow-block bearings

Our pillow-block wheel bearing

Spare Parts and Replenishments
You can't fight a battle without backup, so we made sure we brought some with us to London :-
For the robot - extra batteries (for motors, receiver and transmitter), all kept fully charged, plus lots of cable ties, bolts, nuts, sticky tape, tools etc.,
For the troops - cold drinks and snacks.

Special mention must go to our local Sainsbury's HomeBase who lent us a brand new Bosch drill as an 'emergency' replacement in case any Bosch part got bust. But all our Bosch bits survived intact so HomeBase willingly refunded our deposit - intact.

As it turned out, we needed little of either of these, because

For the robot - our anticipated "battles" were reduced to a single Lightweight Class mêlée, so there was no need for running repairs, and

For the troops - catering at the venue was pretty good, no, VERY good. Perhaps not so good for the spectators though (Charlie's Dad and sister were in the audience!).

Really though, we would have preferred Slippery Strana to have had a much harder time, and had the satisfaction of fixing things on the fly, for which we had rehearsed and practised. What about next year TV21 ???

The Shell - or 'Hood' or 'Lid' or 'Top'
All these 'innards' had to be protected by something, and the saga of our shell deserves a page of its own.

Please go to the 'Shell' page to read about our strongest and largest component




Slippery Strana Home



The Name

The Speed



Amazing Shell

A Good Fight

  Page updated 23rd October 2000