TOWARDS CONTROL

Kirkby on Bain Primary School used some of its prize money from the Design competition to buy a Valiant Control Console. Here the headteacher, Pete Douglas explains its first introduction to the pupils.

The Y6 children in the junior class were busily designing machines to raise and lower as part of their topic work on "Movement". The children worked in small groups on design sheets as they discussed and modified ideas to achieve a workable design. Differing ideas emerged and two groups resorted to Lego Technics to "model" the mechanism part of their machine to see if it would work. This led to one group attempting to motorise their lift and control its movement by slowing down the motor - a problem not uncommon in primary classrooms.

A workable solution was achieved and their investigations found the slowest movement to be a worm gear driving as large a gear as possible. However, feeling Lego was too restrictive and knowing their own design would have to be dismantled if Lego was used, the children decided to use our own system of gears and connectors that integrated with wood strip and other everyday materials. This not only freed them from the prescriptive usage of Lego parts but also allowed them to incorporate and modify their own ideas more freely!

Various problems were encountered in construction which needed to be overcome:

How can we get the lift to rise evenly to allow passengers to travel safely?

Where shall we position the mechanism?

How can we control the motor?

Fortunately, the children's ideas were supported by appropriate resources that were designed to integrate with their own materials, such as wood strip, and standard sizes meant that few difficulties were encountered in fitting the parts together.

A gear system that pushed straight onto a 4.5mm dowel allowed the worm gear and large gear wheel to be mounted and a motor connector allowed the dowel to be turned by a 3V motor, supported by a motor clip. A three-way switch enabled the mechanism to be controlled while the wiring was kept tidy using small self adhesive clips and spring connectors. The final result proved to work exceptionally well creating much excitement, although their original design had changed much along the way!

The lift was a fine example of "control in the environment' of which other examples were discussed with the children. The model clearly lent itself to computer control so I introduced the group to the Valiant Control Console. The Console seemed to have distinct advantages over using one of our few computer systems and seemed a natural development for the children who had experienced virtually the same programming facilities when using Roamer.

The Console was easily transported as the children worked in the corridor. They took to it with ease, connecting the motor directly to the Console, as they explored by trial and error how long it took the lift to reach the top floor and return to the basement. Why did it not take as long to go down? - led to discussions of weight and gravity. The children soon related to the high and low facility for switching the motor on and off and the "wait" facility allowed them to achieve their ultimate task - programming the lift to raise, stop at each floor to collect passengers and return to the ground floor. The list of instructions fed into the Console was written down and evaluated as the "go" button was pressed. The program was run several times by repeating this operation.

Finally, as several of their instructions were being repeated to stop the lift and wait at each floor as the distance between each floor was the same, I introduced the children to the "repeat" facility on the Console. More discussion led to a reduced list of instructions as programming skills were extended and the children closely scrutinised the lift's every move in relation to the program. A successful solution was achieved and the group were keen to pass on their experiences and skills to others to show what they had accomplished.

The Valiant Control Console had provided an important step for the children into computer control. Programming skills seemed to be acquired very quickly and the children were quick to see its potential for controlling other mechanisms using outputs such as lights, motors and buzzers. Curiosity was aroused and questions were being asked as to "What are the inputs for?" Not only that, the Console's portable size allowed it to be part of a "hands on" display in the foyer while the school's computer systems were busily employed for other purposes!