When we first heard that we there was going to be a contraption competition going to be held in our college I was pleasantly surprised . Me and my friend had already tried our hand at Contraption before but failed miserably. Now this time we started again with three other trusty companions.

A contraption is essentially a series of processes that take place sequentially like a ball rolling and knocking a series of dominoes which then switches on a switch. While we din’t have the bountiful resources of those of the Honda accord one or that rather annoying ta-da-di-pa-ti-da-pi :shock:, we embarked on a quest in creating something way more simpler, and cheaper. Here I will tend to list the steps and the processes we used mainly to help anyone make a contraption.

OUR CONTRAPTION = PTO -> Please Turn Over

The team :

Me, Rajkumar.R.K.M. , Karthick , Ramji, Arun Mozhi Varman.

BASIC RULE of contraption MURPHY’s LAW

If something can go wrong, it will definitely go wrong ( In the worst possible moment :twisted: ) . So, always I mean always recheck every aspect of your contraption till the end .


We started off by rolling a barrell which knocks a stably located jug of water. This pours water into a see-saw like arrangement comprising of a can ( a beer can to be exact ;) ) and a candle alight. The water which poured into the can increased it’s weight making the candle come up.

While, to say this seems very simple, the fact in creating the contraption is making it reproducible.

Always try to standardise ” … so quoth RKM.


The candle which upon rising will burn a thread we had nailed down. The thread holds a car on a slope. Once, unleashed the speedy ferrari ( hmmph, except for the fact that it often prefers going off-road ) knocks a series of dominoes down. The dominoes we used were casettes. The row of cassettes upon falling consecutively knocked down a switch upon an extension box.


This powers a speaker and a light switch. Now, we use my mobile phone, which plays tracks in a loop ( No Fear from The Rasmus ) to blow off a ball. This is of course incredibly cheesy making the entire roomful of people turn towards our contraption :mrgreen:


The ball coming down strikes down a row of dominoes. The stimulates a machine which we built this swings away a cover of the LDR ( a light-dependent resistor aka something which conducts current essentially when there is light only ) and also unhooks the breaker we place it in the path of a wound-up car.


Since, the cover of the LDR is already open the current flows. The voltage from there goes to a fan, around which a wire is wound. This wire is wounded such that a ball drops and disturbs a scale propping a ball upon our ‘ Machine of Ball madness’ - a device we modified. This simply rolls ball up the slope purely using slope and a gradient. This finally pops a ball upon a thread which holds our batma ( my unicorn key chain :grin: )


This keys flows down the long chain and knocks of a test tube full of vinegar into a ballon of baking soda. The two react to produce a gas ( probably CO2) . This fills the ballon which expands and knocks of a cassette upon a contact switch. This switch controls a motor.


Remeber that wounded car we unleashed, while STEP6 is occuring this car goes and knocks up a scale with a double-sided tape taped to it upon the page of a book.


Now, when the motor is switched on the scale is pushed up gradually. The tape sticks firmly on to the paper. The motor wounds up, the paper is gradually turned .

Ta da ti ta da pi

PTO - Please turn over.

yup … this is bloody simple but this was a real trap. We spent about a week locked into it. We faced strange stares from people across the house when we first began rolling a ball upon my friend Ramji’s House Terrace. We borrowed ( err … rather without notice :p ) sand and stones from a construction site across the road. We devoured nearly every packet of biscuit in and around the area. We spent a entire day simply playing annoying music loud enough for the entire neighbourhood to hear in our attempt to make the ball fall ( We realised in the end that we needed a woofer to do that). We fought over Rajini cassettes and keeping them last. We wasted nearly two entire rolls of thread. We must also used up clay the amount of all our heads combined :D .¬†We enjoyed watching the car falling off the road just before hitting the cassette. We watched the switch being switched half on and half off :roll:.

Yet, we had fun. We enjoyed the experience. We sure learned a lot. Looking back, it was a wonderful experience.

By the way, we won the first prize :P :mrgreen:

Ipse Dixit
I have spoken.


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