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Handmade vacuum pump
Level: Elementary/Secondary
Concept: Equipment to make a vacuum
Introduction:
Air is so close to us that we don’t feel its existence. We can find that it has weight and air pressure is caused by its weight only by making a vacuum. We can make our own vacuum pump using low cost materials.There are three types of handmade vacuum pump. One is made of a big syringe, the second is made of a bicycle air pump and the third is made of a balloon air pump
Vacuum pump adapting a big syringe
Materials
- 50ml/100ml plastic syringe
- super glue
- a small piece of rubber sheet/ rubber balloon
- 2 glass tubes (outer diameter 6mm, length 5 cm)e) a small rubber bung for attachment A (NO.7)
- a big rubber bung for attachment B (NO.11)
- 2 plastic tubes (internal diameter 6mm, length 1 m)
Fabrication
- Using a heated soldering iron, make a small hole make a hole with diameter of 3-5 mm on the head of the syringe
- Cut out an inlet valve and an outlet valve from rubber sheet/ rubber balloon and paste the first one to inside of the syringe and the second to outside of the syringe using super glue as shown in Fig.2.
- Check the workings of these valves by moving the piston of the syringe in and out.
- (Making attachment A) Make a hole of 5 mm at the centre of the small rubber bung using a cork borer, push the glass tube through the hole and put the plastic tube to it as shown in Fig.3.
- (Making attachment B) Make a hole of 5 mm at the centre of the big rubber bung using a cork borer, make a hollow around the hole, push the glass tube through the hole and put the plastic tube to it as shown in Fig.3.
- Put one end of the plastic tube of an attachment (A or B) to the projection of the syringe.
Science
As shown in Fig.4, when we pull the piston ofthe syringe, the exhaust valve closes and theinlet valve opens and air comes into the syringe.When we push the piston, the inlet valvecloses and the exhaust valve opens and the airin the syringe goes out. Thus we can make a vacuum in the container which we want to evacuate by pulling and pushing the piston of the syringe. 
