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.