ten little fingers - arvind gupta (4 mb pdf)

BELLOWS PUMPWith this very efficient pump you can inflate a balloon with air or fill it with water. This pump will alsomake a great Pichkari for Holi, for with every down stroke 40-ml of water comes gushing out.1. For making the pump you will need twofilm-reel bottles, 15-cm of old cycle tube, anold refill or a Frooti straw, and some rubberbased adhesive like Fevibond or Vamicol2 Make a hole in thebase of film-reel bottleA by using a dividerpoint. Widen this holeby gently rotating thepointed end of ascissors The holeshould be about 1-cmin diameter and shouldnot have any burrs.3. Make asimilar holein cap B.4. Cut two circular washersabout 1.5-cm in diameterfrom a cycle rubber-tube.Apply Fevibond on half ofthe area of the two washers.5. ApplyFevibond to thecap and pasteone washer.6. The washerwhich is stuck onone side only willact like a hinge. Itcan open and closelike a valve.This is theDELIVERYVALVE.7. Paste the othervalve on the base ofthe film-reel bottle.This is theSUCTION VALVE.8. Take anotherfilm- reel bottle Band make a smallhole on its cylindricalsurface.9. Press fit a short thick Frootistraw or a ball-pen refill in itfor the delivery pipe. Fix thecap with the delivery valve(Fig 6) to bottle B.DeliveryValveSuctionValve10. Cut a 15-cm long piecefrom an old bicycle tube.Stretch and slide the tubeover both the bottles asshown. The bottles will beseparated by 7-8 cm ofcycle tube. This rubbertube acts like a pair ofbellows.11. Now hold the lower bottle in water andpress the top bottle B downwards. After afew initial strokes water will start gushingout of the delivery tube.