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Demotech News


News Sat Feb 10 (2007) -- Fri Apr 22 (2016)
News Tue Jan 25 (2005) -- Mon Sep 25 (2006)
News Fri Jan 09 (2004) -- Tue Jan 25 (2005)
News Wed Aug 27 (2003) -- Tue Dec 16 (2003)
News Tue Jun 03 (2003) -- Thu Aug 14 (2003)

Making news

Thu May 22 (2003)

Ives Faye will get some well deserved publicity from the Dutch EO-television broadcast company for his garden project in Senegal, where the new well is finished, offering plenty water at 40 meter depth. He phoned me only a few days ago that he would come today to our workshop together with a television crew.
Short notice for me. I could not prepare the well mockup, the full scale model to give people in Keur Mousse in Senegal an idea what we expect to build.
But I just finished in time a new way to make the plastic rope bearing for the pulley wheel axle (see picture). It asks for a lengthwise cut in the end of the frame rod. I expect a blacksmith can get it done when the ends of the frame are made red hot in his furnace. With this setup it is much easier to wind the rope cross wise from the frame over the axle buts to form the bearing. It looks neat and effective.

Ives and his wife told the television people the story of the why and how of their Keur Mousse project. I had liked to focus attention to the pulley wheel, but Ives choose to put the rope pump forward. Together with Ives' and Els' their kids, I explained once again in front of the camera how the rope pump works. In just under ONE minute!

Evaluation of Demotech's presentation on the web

Sun May 11 (2003)

The weekend was used to reconsider the presentation of Demotech targets and policies with the means available in a website. The question of what Demotech is about, stood central. Currently the menu-item 'About us' links to text, but this text may not clarify in a visitor's mind the exact direction of Demotech's policies. How could this be done better?
Richard Zuidhof, Marc van der Kamp and Rejo Zenger have the experience in web-design to offer alternatives. It was my task to relate these alternatives to the present setup of our website.
The usual way in which presentations are made to an audience with a projector and images using MS Powerpoint seemed an effective as well as attractive option. It could combine short bits of text that relate (and are hyper linked) to a cluster of information. Such text could be displayed with a related picture as background. Text items with background could then be presented as a series of slides. How could this idea come together with other demand for a presentation of text related to images?
Two more text-picture related items need attention. One being the downloadable manual of a design. Which is what future users need. The second is the description of prototype development process. This is essential for making use of the feedback from others through the website. People collaborating with Demotech do not need a polished presentation, just a rough and sketchy presentation will do.
Rejo and I feel attracted to the simple but clear set up for a construction manual found on Internet. Marc promised to look into the possibility of programming the above three options for the Demotech website.

Search and what we are searching for

Mon Apr 28 (2003)

Should this website have a glossy finish before it is published? People accustomed to regular product promotion will say "yes, it irritates to look at unfinished and untidy stuff. There is no compagny who dares to risk that".
This website for sure, does not have a glossy finish and I doubt if it ever will have a finish at all. I like to take the risk because:
- The basic innovation, that we pursue, cannot give a final result for a long time to come. It is impossible to program its progress with any certainty.
- Anything left unfinished is an invitation to others to join development. What we publish, we publish as a contribution to Open Source interaction.
- Time is better invested in continuation of design instead of in an in-between stop.

Today I had a conversation on this subject with Dina Septiani (see picture), a student at the University InHolland in Diemen. She came over to our workshop for an interview about our website.
It struck me how much intellectual capacity is available in the environment of a school as this one, also remembering our interaction with its students Ayunda, Zhu, Farah and Lillian, half a year ago.
Over the years, interaction with students has always been very inspiring. They said it was inspiring for them, we felt the issues put forward by us, really mattered for them and could count on support in some way later on. Could it be that there are better ways for interaction between students and Demotech?
Last Saturday Rejo and I discussed with four students of the faculty of Industrial Design of the Delft Technical University how to shape an "inspiring environment on design for sustainability". At stake is the use of our workshop in Dieren. How to link our "inspiring environment" with the wish of students to have some reference from a radical design approach?
Some ideas were put forward, we will continue to work on them.

Today a big step forward was made with our website. As our website will soon contain more than five Megabyte of information, it will be a good thing to be able to find information by a search query. Marc van der Kamp has now created this potential. From now on it is possible to fill in a key-word in a search window and get the immediate result neatly sorted out by our database.
Marc is working on extending this search capacity. Soon it will be possible to sort information on categories of design, progress made so far, design targets and many other issues.

Forking in ventilating the chimney-less wood stove

Fri Apr 25 (2003)

Forking is the expression for a split in approach, a new way taken up next to the research that goes along according to a previous plan.
Bram de Vries, one of the people I recently met through the contact with LHUMP thought different about a method to create the draft of air through the stove.
Demotech proposed the use of a Stirling engine. Such a machine could have a very low efficiency, as heat was plenty available in a stove, while the energy needed to drive the ventilator was but a little.

However Bram asked himself the question how to reach the same effect with even less moving parts. Today he came over to our workshop to discuss and demonstrate his ideas.
He started experimenting with a tin can functioning as a vessel to heat up air. Over this vessel a rubber membrane is attached with an air valve in the middle. This valve should switch at reaching the top and the bottom of its stroke, thus creating a draft by sucking air in and pushing air out.
Bram realizes his forking concentrates on a mechanical train of thoughts. Next step is to discuss it with people who can make a proper calculation, as the expansion of air by heat can be properly calculated. To inspire these people he plans to make in his kitchen at home a new set up, clarifying his idea better. Such a contraption could even shown a first sign of life!

Try-out for a better use of the width of a 15 inch monitor

Wed Apr 23 (2003)

The machine that organizes the data of this site is working to full satisfaction. No, it is not yet complete. Yes, some more components will be added by Marc van der Kamp and Rejo Zenger. However it was time to look again at our site with the eyes of our customers.
English speaking visitors may like to read about some philosophy on technology that we present in our publications, project descriptions and plans. But if this Demotech site should be of any use to people in Third World countries, the best would be to omit the use of written text all-together. Just pictures, graphics and photographs should tell the story and for that reason should use very many of them.
What would be the generally used size of the monitor? I should check it, but I guess it is 15''. To make best use of the 800 pixels offered in the width of such a monitor, I can use slightly larger pictures. Not 114 pixels width, but 140 pixels per inch.
For Rejo it is not to much work to adapt the general layout of the pages. But for me it will take a considerable time to resize a hundred or more images to the new size.
Best solution would be to get some assistance for this job. But also when I'll have to do it myself in clumsy slowness, even then it will give me the good feeling that the ability to explain our ideas has improved.

Smart mice

Wed Apr 16 (2003)

To filter the waste water of our workshop while using it for growing flowers or vegetables, we made a glasshouse against the wall of our barn. We used techniques as promoted by "De Twaalf Ambachten", such as lowering the glasshouse half way into the ground to collect in the cold season some stored warmth from deeper layers.

Under the cover of this glass house shallow trays filled with a mixture of shredded foam plastic and compost are attached to the brick wall of the barn, facing South. Our neighbour Paula had put a diversity of seeds into these shallow trays.

Yesterday I received my first feedback from nature: notwithstanding a glass cover mice found a way in and dug up and eat most of the planted seeds.
Trying to be smarter then mice, I used a lot of waste glass strips. I placed them close together with only a narrow slot between them for ventilation. The space offered under the glass cover should be high enough for the seeds to grow up some more. When then the glass strips are removed, Paula expects the plants will not to be appriciated by our mice anymore.
However such a protection is not in line with the more simplified setup for growing vegetables as described in the project idea Green Walls. According to this idea there is no need for a glass house. A plastic cover hung over the plant trays could give the neccesary protection. I doubt if this plasitc will also give protection against hungry mice. Yet this problem has to be solved.

Old and new dreams, but repair continues

Mon Apr 07 (2003)

Some more of the repair of the roof of our workshop was done today by Hans de Haas, seen here preparing to apply thatch around one of the roof's corners. To get at that spot was not so easy however and asked for a lot of preparation

Reason for difficult access was one of Demotech's old dreams being in the way, namely the DAF-truck. This truck was once bought with the intention to transport the team that would give instruction in Ghanean villages. See for this very promising project The Mobile Training Unit. Sadly we could not materialize it up to now.
We build a platform attached to a ladder standing between the truck and the side of the barn. The picture shows Hans working from that position.

It is a new dream to replace the DAF-truck, as a costly and difficult to manage travelling tool by a different type and ultra light travelling tool, the Traveling Bed.
With Paula I made the first successful test with a loaded frame construction. I want to be able to repair or replace this frame construction at any place I could travel to. The interconnections as used in the first test was to complex for that. The aluminum tube-like fittings are now replaced by tin, cut from a bean can, nailed to tiny bits of wood, resulting in similar fittings.
These frames fit into the box of the Travel Bed as shown in the third picture.

Repair of the thatch roof

Thu Mar 20 (2003)

Good use of a sunny day was made by the start of the actual repair of the thatch roof of the Demotech barn. Hans de Haas and his son Arjan, both experienced thatchers, started work by removing the old thatch and some repair on wooden parts. To attach the new thatch to the battens is carefull work that will be continued today by Hans.

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Message from Senegal

Thu Mar 20 (2003)

A message from Keur Mousse in Senegal reached me about a slow-down in the digging of the well. This because of a very hard layer of laterite just above the water bearing layer at 35 meters depth. Demotech in the Netherlands has now some more time to provide a proper design and a scale model for a well cover. Such a scale model, together with pictures and instructions by telephone should help to communicate the ideas of Ives and me to our friends in Senegal about the well cover.

In our garden Rejo and I made a mockup of the well looking like the well in Ives project garden in Keur Mousse (see picture). Build with adhesive tape from plastic sheet and bamboo sticks, it will give us the impression of size and energometrics for the proper functioning.
This is what we want to achieve:

  • A well cover, first to be made from wooden boards as a prototype. But for the final product metal profiles and sheet is preferred.
  • The person hoisting waters should stand on it in the middle, a container of some 200 liters will be positioned close to the edge. The construction of the well cover has to take this load without the slightest risk.
  • A frame is constructed on top of the well cover to attach the pulley. The person lifting the water from the well does this by pulling down the rope running over the pulley. The frame has to position the pulley high enough over the person to allow an upward movement of the arm to grip for the rope.
  • Rombout has made a frame for the pulley wheel (see picture Rombout spinning the wheel). It puzzles people that the metal pins sticking out of the pulley hub (the actual axle) run in a rough winding of plastic rope with so little friction. They expect the axle has to run in a metal support. It takes some explaining, that friction of steel on steel causes the rapid wear of the normal pulley construction. Apart from giving long service and low friction, the "rope bearing" is also very easy to make and to repair.

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    LHUMP people getting involved

    Mon Mar 17 (2003)

    The people we met at the LHUMP-fair got a mailing with details for a meeting at Demotech in a weekend in the beginning of April. One of them, Rombout den Ouden did not want to wait for that and worked with us on Tuesday last. He choose to tackle some refinements needed for the Senegal pulley (see picture). A method was developed to mount the spokes with considerable more pre-tension than before.

    The second picture shows Rombout testing the bicycle with the instant load rack. As a design challenge he will adopt the project to construct a brake on the rear wheel, also instantly to be made from bits of rope, metal wire, wood and rubber.
    In a similar way other LHUMP people could get involved in Demotech work, each with her or his own project or working together in small groups of two or three.


    News Mon Mar 17 (2003) -- Wed Dec 04 (2002)
    News Thu Nov 28 (2002) -- Mon Oct 21 (2002)
    News Fri Oct 11 (2002) -- Tue Aug 27 (2002)
    News Tue Aug 27 (2002) -- Mon Jul 01 (2002)