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 Home | Death Valley | Scientists | Jonathan | Rover Diary - Day 1
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Jonathan's Rover Diary Day 0 1 2 3 4

Day One

The first day of any filming is usually a long day as there are all sorts of shots to get to set-up the series. I get up about 4.30 am and am ready with the rest of the crew for a 5.30 am start. The series starts with us Roughies flying into the new location in a helicopter.

What is strange about this first day is that the desert is cool! Of course it is still early but it is surprising that it is so cool.

Our challenges for this first programme are varied and include finding water in the desert, purifying it to drink and - my personal challenge - to build a remote control ‘Mars Rover’ machine to explore the area!

For this challenge they have given us quite a lot of high-tech, though basic, household type equipment including battery powered power tools, a guitar tuner and various car type electrical parts and wires. I take one of the drills apart to see how the speed control works and to best understand how I might fix it in place and attach it to the wheels I found on the mine tip.

My first design uses 3 small bicycle wheels; 2 driven by modified electrical hand drills and the last wheel fixed in place on the rear. The thing looks like a sort of Reliant Robin but we have named it the Martian Tok-tok in honour of those 3 wheeled taxis in the Far East.

The idea is that the device is to be powered using the two motors from the power drills, with the wheels being fixed in the chucks of the drills. When power is applied to the drills they turn the wheels, moving the rover. If both the drills are on then the rover goes forward and reversing the motor connections will make the rover go in reverse. By reversing one motor wiring with respect to the other you can make the rover steer left, or with opposite connections - right.

I have already found a problem with this design, though. By reversing the power to the motors I have a simple way of making the Rover change direction. The problem is that as the power is adjusted to steer the vehicle to the left or right, the rear wheel tends to pull sideways when it's meant to be heading forward. It is especially bad if the rover is going slowly and in fact the effect brings the rover to a complete standstill. I hadn’t thought about this problem – what we need is a wheel that is free not only to go round but must also be free to follow the steering like a caster on a piano or the wheels on a trolley.

Good day – much progress.

The Rover
The idea of the rover would be to use the machine to navigate an assault course using only the remote control facilities we could make ourselves. One last challenge was that we could not see the Rover directly and that they would give us a wireless radio camera that would be fixed to the Rover so that it can send back pictures from it – we have then to navigate using this information from the live pictures!

Remote Control
There is a very simple but rather nice way to get the thing to be controllably remotely. Firstly they gave us two walki-talkies and a guitar tuner. The tuner has 5 LED’s that light when the correct note is played near to it (it has a built in microphone). I intend to take a wire from each of the lights and use this little signal to drive a relay that controls the motors. We can make use of what is called diode logic to program each LED output with a particular function.

For example the first LED will make both wheels go forward and so the rover will go forward. LED two will make the left wheel go forward but at the same time make the right wheel go backward – this should make the rover go left. LED three will do the reverse and make the rover go right. Finally LED four will make both wheels go backward and so the rover will reverse. No LED’s means there will be no signals and so the rover motors are off and the vehicle motionless.

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Jonathan builds his rover
Scientist Diaries

Water or wheels? How did the other members of the Rough Science team cope with the first challenge? Read their diaries to find out:

Ellen
Iain
Kathy
Mike