DOWNHILL RACE

We have fabricated the Discs using Laser cut 4mm SS sheet bolted with 3 nos of one Kg standard weights in each Disc set. First we had made the Discs to roll down on the SS ramp along with SS tube guides.The results were not consistent .We changed the design so that the Discs were made to roll down on the Pipes from the Axle in the Disc.We also smade one more improvement that is we made the whole table to swivel, so that there was no need to lift and move it by hand to the starting position. The Discs are made to climb a ramp at the end of travel so they come to a rest without impact.

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FALLING SEED AND LEAF

Bottom cams have tilted the Trap doors to allow the items to fall through

To Charging position : Handle is turned to take the items to Top dropping position

Dropping : The chord is pulled gently to operate the trap door to release the items.

View of the trap door when chord is pulled.

We have used two sets of 75mm Acrylic tubes one for air and the other for vacuum. Each tube is joined at the centre with a collar as 4ft tubes were not available and long tubes are necessary to observe the effect.The air is removed from the vacuum tube using a pump with quick change coupler. The pressure gauge mounted at the end of the tube gives the status of the vacuum pressure. As the feather sometimes stuck to the tube we decided to use leaf and seed as the exhibits of light and heavy objects. The tube assembly is mounted on a board , which is mounted on to a FIAT car front wheel assembly . Trap door flaps are provided in each tube to keep the object when rotated and to release when required. Cams also assist in this operation. For dropping the door is operated by pulling the thread. The doors are linked to the external levers through button magnets. This Exhibit was a challenging item for us. Inside the exhibit we have loaded the assembly with two cement concrete blocks to increase the stability of the exhibit.

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TURN TABLE

We have used the Fiat car front wheel axle assembly with special mounting, We have only one set of compound pulley with vee belts which connects to the wheel tire holder which acts as a pulley. A standard 1400 rpm motor is used with a timer. The turn table speed is 65 rpm. The Rotating disc is a stainless sheet that is glued to 10mm Phenolic sheet. The Round shape was ground in-suit after fixing , thereby ensuring good concentricity.

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MOMENTUM MACHINE

These "Child Inspectors" are certifying the exhibit with a "VOVH" before dispatching it to the science centre

The assembly showing the wheel axle and Rotating platform

Hub assembly in place

....................................Frame work details

We have used the Fiat car front wheel axle assembly for the movement. As the assembly was inclined to the swiveling posts, suitable clamping was made. Top plywood was fixed to the hub flange with an iron disc. The entire platform was covered with Vinyl. Foot print were made with round head star screws.

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BALANCING BALL

This is a favorite hands on exhibit among children. The exhibit is very simple in construction. A standard hand blower is fixed below the table. A wooden box is made around it to reduce the noise and a filter is fixed to the in-take holes. A wire basket is placed above the table so that the Ball always come in contact with the air blast when it comes down .

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