Meccano Society of Scotland
"Carry the Can" Competition
No less than eleven competitors took up this years challenge for our all-day get-together. Their task, to devise a machine capable of transporting a tin of baked beans as far as possible, using only the power of a clockwork Magic Motor.
A wide range of vehicles were each put through their paces along the floor of the Menstrie Scout Hall. Once again the ingenuity our members kept the judges busy. More than half the entrants carried their cans the length of the hall, an impressive feat for such a tiny motor. It's a shame the old Meccano Magazine never really advertised the potential performance of clockwork motors.
Jim Gregory carried his can on a trailer towed behind a clockwork tractor, which was a fine scale model in its own right. Others also opted for a power-hungry solution to the problem. With its powerful reduction gearing, Jim Wood's vehicle might have won a hill climb or the tug-of-war event, but sadly this wasn't it.
Angus Plumb's tricycle-like machine was compact, with great economy of parts, but unfortunately reluctant to travel in a straight line. There were good performances from the creations of Alan MacDonald, Douglas Carson and Margaret T, generally using vehicles tyred wheels, which travelled far before becoming tired. Alistair Nichol used Face Plates as his wheels for greater efficiency.
Alan Blair's well-engineered machine achieved 4th place. It made use of 6" Pulleys as driving wheels. Ken Macdonald's machine was larger and although heavier looking, was probably the fastest vehicle competing and it achieved 3rd place. In second place was Robert Jones, who had used a pair of circular Channel Girders to construct a large drum with the bean tin, held at the axis in a cage of rods. The clockwork motor was slung within the drum, driving the axle. In a previous competition (2001) I slung a larger motor within a drum built from 7½" Circular Strips which travelled further than rival wheeled vehicles. I think Robert's drum suffered some braking effect caused by the viscosity of the beans constantly churning and dragging against the inside of the tin. Try rolling a tin of beans and a tin of soup: the soup tin rolls more easily. I'd built my own 7½" drum with both the can and the motor suspended from the axis, and was able to get a little further than Robert. As a judge I wasn't competing, of course. In any case, somebody had got a better idea.
That person was Rod Bessent. He'd come up with a winning combination of thin 7½" driving wheels supplemented by 6" Pulleys as idlers. The driving axle was mounted in low friction bearings built from paired overlapping Face Plates. Rod had put the motor near the centre of the chassis, so the drive band was almost pulling the axle up out of its bearings. By mounting the motor on long bolts set horizontally, Rod would have been able to optimise the tension on the drive band: enough to grip the pulleys, but not so great as to cause excessive friction.
So here then are the results of the 2006 competition, the distance travelled by each competitor's vehicle, measured in inches (naturally!) using Tim Edwards tape measure:
Chris Shute (Judge)