Category: Uncategorized

Prototype 4

Subir / / Uncategorized
Finally i have finished the prototype number 4. This one is the most complete one with each set for the two legs. Here for fitting the legs Nicola suggested i use his inline skate shoes for the purpose so that there is no need of other kind of wheel supports(the ones needed to  keep the wheel upright and at a certain angle to the leg).

However its clearly visible the support to attache the shoe to the aluminium stand did not survive the pressure of me standing on it. The welding may have made it weak since its aluminium. Just to give an idea, the main structure looks somewhat like this:
So finally i had to resort to rethinking about the most important thing. Finally i made the following design.

The 2 base wheels are attached the the shoes through a 10 degree bent 3 mm aluminium plate and bolted with spacers together. note that the plates on each side of the wheel are of different sizes to incorporate the shift due to 10 degree angle. The rest of the support and wheel are attached like this:

 And finally its not so difficult to stand on them independent of any support, atleast for a moment now 😉

And ila tried it too, although the shoes are quiet large for her. So we have a first review and needed improvements:

  1. We need brakes, for safety and for learning
  2. could be made and should be made far lighter than the 2.63 kg each, as of now.
  3. there is some constant pressure on the front part of the foot to keep the wheel in the right angular position. this is so because of the flexibility of the skating shoes at the ankle which needs to be minimized.
  4. the wheels of one of the wheel sets is jamming too much due to correct fit. To take into account the little irregularities of the rim(spoke holes) and the wheels too, we must make them slightly undersized.
  5. sharp edges must be removed.
So today and tomorrow, we will try, and lest see if i can post a video!!

Project description

Subir / / Uncategorized
The intention is to create a personal transportation system that is a cross between a bicycle and a skate. Each leg is strapped to a large wheel, 20″ bicycle wheel as shown below in the third prototype.

Such a device will help in skating on rough terrain and village roads. A real application is addressing public commutation problems when large distances are involved to access public transportation services in developing countries.
Check out this interesting video :

Surely its not an easy implementation due to the various challenges. But more prototypes are on the way. This will be presented in whatever form, working or non-working in the makerfaire at rome this october 2013. www.makerfairerome.eu.

To make it really opensource and to see any light of the day, all are really welcome to comment and post experiences and suggest updates. I would be delighted if you have better ideas or totally opposite views. I don’t believe in any licensing(as if its a really great idea), so please feel free to use this for any use, it will only be my pleasure.

Subir / / Uncategorized
about the insignificant


it feels like writing again,
feels that what needs to be
can only be begun sometime
an inconspicuous time,
often this is the romantic spirit of idealism
often this minor effort will wither away into the average
but wont it be, even otherwise, the average i mean?


why make fun of the little ones
why neglect them as trivial and unimportant
why so, even when these
in ever so insignificant ways build what we understand by momentum
and momentum isnt that all that matters?


i doubt if major efforts and waiting for them
have ever been of significance
and one may question wherein comes the major effort from
but from a general momentum
built in ever insignificant ways
in ever miniature forms
little revolts here and there
the littleness hides the human nature


and a momentum is sure to be built
a momentum that is anyways built
and when it is built, its hard to brake it
to tame it, to control and release
and who comes to the rescue?
are little friends, miniature efforts


the making of an artist or an inventor
of an leader and a peasant
is not due to the bold stroke of genius we all hear about
it is the nurturing and practicing of the medium of expression
of years of little efforts
years spent in learning the language that can speak creativity
that can dance and walk on a tight rope, with energy and lack of fear
and all we notice is the miniature effort that makes all the difference
that sums up all the rest and thus hides from us
the ignorant bystander


and then we ignorant people, we ape these minor finishing touches
as real standalone efforts
to replace the artist/creator and fail
fail miserably cause we come to know how difficult an effort it would take
and thus we conclude, oh the ignorant bystander, how much of a genius it takes


and we live our lives with this learning embedded into our living
the importance of a certain kind of effort ever increasing,
of bold strokes and radical ideas, the illusion of glamour
and we neglect that what can build a momentum
and thus we fail again, and again we conclude what a genius it takes,
but this time, we also conclude that we can not.


and sometimes, we wait for our bold stroke of creativity,
and never make the smaller ones that might give momentum,
because our yardstick is just so bigger than what we can manage to do,
and so we wait for the enlightenment, we dream for the big moment,
we are desperate for the minor sparks of opportunity that we might come across,
and we neglect so much…


and thus fails another artist, even before the journey began,
ignorant and disillusioned, and convinced that it takes a genius,

and mistakes it as hardwork instead.

greed, growth and efficiency

Subir / / Personal, Uncategorized
the habit of trying to move mountains:
there are two types of people who can break stones, the first is the simple stone breaker, who sees the stones and takes a hammer and breaks them. and then there is another type, the ‘intelligent’ one, who wants to achieve more than the simple one i.e. break more stones than the simple man, with lesser actions/resources but more thinking….achieve more with one go…

the latter creates ideas, makes assumptions, measure resources and strategizes over how to be ‘efficient’ in breaking stones. he puts a lot of effort in thinking and researching other tools, with the ultimate goal of higher efficiency. after numerous experiments and years, he develops a design that can break 5 stones in one go, but requires additional resources, more metal, fuels and is costlier than the humble hammer. its requires time to manufacture and labour. so the tech guy see this as an opportunity, convinces 5 stone breakers to leave their profession and join a labour camp to make stone breaking equipment. the balance sheet is balanced, the prices, wages are fixed, etc. its a profitable business. u can build a 10 stonebreakers/month, each with a capacity to replace 5 stonebreakers multiplied with the ability to replace another 10 by working day and night, and thus the process is very efficient.

By the end of above paragraph,  the ‘tech’ have ‘liberated’ 150 not-so-perfect-and-efficient-machines, the human stonebreakers, from the back breaking work, and gained a huge ‘profit’. so its is only ‘sustainable’ to continue and more such machines are built and distributed. profit is tastier and its a pleasure to have as much. however, what about the 150/month of free souls? well some are as enterprising as the tech guy, so they decide to compete, and you have another 150/month count of free souls. well not everyone is interested in replacing stonebuilders, so some start building the farm machines. more free souls. and so on….

free souls(humans) are not sustainable and peaceful in general and they start to create menace, so the government decides to employ them, create jobs. also one of the tech guy decides he doesnt want to just build some stonebreakers, but many and for that its would be efficient to takeover other companies. to do that it would be more efficient if force is used instead of buyin it out, so he asks the little government of ex-stone breakers and ex-farmers to help him take stuff from the other, and a new profession is born, the militia. after the takeover, the government is stronger, the military gets more men and funds are available to develop new industry of this war machines. other people are scared and they develop their own militia, and efficiency of operations increase globally.

then there are some subtypes of the tech people, who spend all life studying the stones and finding out how to break them more and more efficiently. they branch out into various techniques and stuff. some people get bitten by the bug of exploration and leave the trail that heads back to industry, and they delve into theoretical physics,maths…and yes, they are ofcourse fed by the government since now the governments know that there is chance that these guys may make the processes more efficient.

in all, tech is created to increase efficiencies and it also creates more free souls, who enterprise to create more tech and more free souls. just like a stack of cards, the only difference being that the cards are dynamic. this process of super efficiency : replace more with less, continues creating the world today. all to break simple stones…funny.

it seems greed and efficiency are quiet related. well we have examples right in our own brains. often we dream, and imagine of moving mountains, because you know that it is the most efficient of all thoughts. by moving mountains i mean being successful at first go, become the richest man on earth, become super intelligent, ultra cools and others…..well if you ask the question why do you want to move anything in the first place, then you must head back to the start of this story and understand why a stonebreaker was ‘inefficient’..we dont like inefficiency at all, its very annoying…so why try moving stones when you can imagine moving mountains. why do the ground work when u can see the sky…

the idea of ultra-efficiency is very lucrative and we fall for it. There are 2 side-effects of this persuit, 1)you spend enormous time dreaming 2)you build a virtual image of achieving the dreams and the feelings you will posses then(if you do). it is very tempting and so much that it becomes a habit. the images in your head become stronger and stronger and for you its is an unacceptable contrast to the reality around you. When the time comes for living in real life, u expect yourself to move the mountains you always have imagined you are able to, and you fail. the fall from the castle of dreams is so large that it dents you pretty permanently. however we try some more times, till we realize that we cant do this, that the world is not a fair place for you to be, that your life is doomed. however you still cant let go of the dream, its a habit now, years of dreaming cant be wished away. it would require years of practicality, of reality, and that to only when you accept that you are a stonebreaker by birth, you can only move stones rather than mountains. that efficiency is nothing but greed.

life is not doomed, it can only be worse. if you stick to the moving stones, you can move the mountains some day, but dreaming about ultra-efficiency is a disease. you must fight the illness or else fight the reality.

the state of world today, is a result of greed and we continue to participate in it. we value efficiency more than human life. we value concepts of our mind more than the lives involved. the question that must be asked , humbleness or efficiency? 

Viscosity Drive Stirling Engine

Subir / / Uncategorized
I am currently trying this one out, so please let me know if you are interested in the results. So far i am just making it out of coke cans and stuff..
This is a stirling engine concept, a mix between FPSE and fluidyne engine.

As you can see, there are two chambers connected with a tube. in one of the chamber there is a displacer with a long rod dipped in the liquid piston(water). the unit may be hermitically sealed and pressurized. 
You must get familiar with FPSE engines in order to understand the potential merits of this design. Assuming you have done so, i begin:
There is important difference between an FPSE and this VDSE(viscous drive Stirling engine). in an FPSE the displacer is actuated by its own spring or gas spring, independent of piston. actually the displacer is a leader. however in case of VDSE, the piston leads, actuates the displacer and completes its full expansion before actuating the displacer again. this is due to the viscous drag. in this way, the displacer would not obey a sinusoidal relation with time, and hence the PV curve would tend to be more boxy rather than circular, giving some potential extension of PV area.
so the cycle is as follows(from the figure)
  1. The engine is supplied heat at the top, the little gas above displacer expands, pushing the liquid level A into the tube.
  2. This movement of liquid, the speed in the tube would be a multiple of speed at level A due to difference in diameters, and thus will drive(viscous drag) the displacer rod at a similar speed.
  3. The displacer moves and thus remaining gas below displacer moves to the hotter top, increasing the driving pressure. 
  4. The displacer and water level keep moving down, and after full expansion( due to momentum gained by heavy water column), the expansion process stops.
  5. In case of an FPSE, the displacer would have reversed much before this complete expansion. This is so because the displacer is driven by an actuator(gas spring) different than the piston’s actuator. Thus it moves back to the top pushing the hot gases back to cold chamber even if they still have more potential to expand. This action stops the expansion of the piston and results in the corners of PV graph begin circular or clipped However in the VDSE, the displacer is driven by the same piston(water) and so the things are slightly different.
  6. The water now flows back from reservoir through the tube into the engine. Only after this motion, the displacer is actuated by the viscous flow of liquid around the displacer rod, and the displacer reaches the top. The hot gases are compressed by the incoming liquid above water surface ‘level A’.
  7. this compression continues till the momentum of liquid is reduced to zero. Again in case of an FPSE this would not have been possible as the displacer would have started moving downwards much before complete compression is accomplished.

So as you can see, the area under PV curve is potentially increased. the speed of displacer movement is different from piston which cannot be realized in conventional engines(hence the circular PV curve). this (ideally)discrete motion of displacer is what makes this concept very interesting.

As for viscous losses, we are lucky, that these losses dont scaleup with pressure, although the speed of operation must be kept low to minimize these.

———-
Updates:
Well i tried the above idea ..here are some pics

..Well the result was the following:

  1. With the heat sources(hot air gun / propane flame) the flow of water to the other column was too slow to cause any drag. the reasons might be the displacer rod dia is too large, causing a large drag and hence slowing the water flow.
  2. i have no idea how much water was filled in. next time i will calculate.
  3. when i removed the green pipe, at the end of experiemnts, there was still some water left in the chamber, and this again proves the 1st point, the displacer rod dia must be smaller so as to permit free flow at high speeds..
well thats all, so i have to modify the dispplacer rod diameter…sorry i dont have the pics of these(displacer and rod). will post shortly.
thanks 🙂