ten little fingers - arvind gupta (4 mb pdf)

A TOUCHING SLATEThis slate can help blind children in recognising shapes. But it is great fun for normal children too.Dr. Dilip Bhatt designed it for his blind son. Dr. Bhatt works for the Indian Space Research Center(ISRO) in Ahmedabad. As you write on this slate, wool comes out of a pen and sticks to the Velcroon the slate.The SlateThe actual writing is done onthe Velcro, which is supportedunderneath by plywood. StickVelcro strips on a rectangularpiece of plywood to make thisslate. Velcro comes as a strip.It has got thousands of minutenylon hooks on its surface. Thefibres of the wool stick to thesehooks.The PenThe special pen is made from afilm roll bottle and the outerplastic casing of an ordinaryball pen. A hole is made in thebase of the bottle. The pen isfixed in this hole with a piece ofshoe rubber and some Fevibond(rubber adhesive). A small wire(cycle spoke piece) is bent intoa ‘Z’ shape to make the crank.A small pulley - made from apiece of shoe rubber is attachedto the crank. Two holesare made near the mouth of thebottle to fix the crank. One holeis slit for easy fixing andremoval of the crank from thebottle.Take 1.5 meters of thin wool.Tie one of its ends to the pulleyand then wrap it around thepulley. Weave the other end ofthe wool through the bottle andthe pen body. Tie a thick knotat the writing end of the wool.Now place the crank with thewool in the bottle.Hold the pen and start drawinga cat on the slate. The woolwill come out of the pen andstick to the Velcro. To erasethe picture simply rotates thehandle. The wool will getwrapped around the pulley andthe picture will disappear. (Illustration by Henrik Johansson)