Demotech News

News Tue Mar 23 (2010) -- Tue Sep 23 (2025)
News Mon Apr 03 (2006) -- Thu Jun 19 (2008)
News Wed Nov 24 (2004) -- Fri Oct 21 (2005)
News Sat Oct 18 (2003) -- Wed Jul 07 (2004)
News Thu Jul 31 (2003) -- Sun Oct 12 (2003)
News Fri Apr 25 (2003) -- Fri Jul 11 (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.

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.

	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.

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.

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.

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.

The south side of the tach roof of our barn (=our workshop) is in bad condition. Out of the blue, two very special people popped up offering help with the repair: Hans de Haas and his son Arjan. Hans has a special practical knowledge of basic handicraft work, such as axing timber out of logs and the construction of roofs in days long past. He did action-research on such technologies as used in the stone age and in medieval periods.

Arjan de Haas has a similar expertise and is involved in a development project in Senegal. One of the technologies he introduced in this project was -to my big surprise- the rope pump! There seems to be plenty of overlapping interests in both our field of work and expertise. I am looking forward to the chance to work together on the roof this week and on other projects later on. As a contribution to start with, Hans en Arjan donated bundles of reed they loaded on my trailer as the picture shows.

Yesterdays one-day fair of the LHUMP proved to be a very productive gathering. Rejo Zenger and I set out to contact students who would like to share our work. More than a dozen students were interested in a followup. During these first contacts students expressed interest in a multi-day stay at the workshop of Demotech to get the feel of the potential the Demotech action-research approach could have for them. We promised to try to organize such a 'design-in'.
Apart from productive, this gathering was also a very nice follow-up of the workshop we did with the LUMPH.
Our stand was situated next to a food bar offering beautiful looking and tasting food. Apart from this food and the free smell of it, we got all the help from the LHUMP-people we needed.
Many students browsed through our website on our computer and used the entry form so we can send them follow-up information. This form is still accessable here.

On March 5th, Demotech participates in a one-day fair, organized for students to select and arrange their internships and assignments. However, this fair is dedicated to such assigments and working practices that relate to environmental care and development studies. The initiatieve for this fair is taken by LHUMP, an inter-university platform for the promotion of student commitment to these issues.
For a description of the internships and assignments Demotech offers, click here. As soon as time permits, we'll translate the Dutch text into English.

The small result from my visit to Senegal: only four days working in the village Keur Mousse, one week hospitalized in Dakar, two weeks recovery, now back in track in the Demotech workshop. Some impressions are noted here.

During a four days visit to the village Keur Mousse, Ives Fayes showed me the location of his garden project. In one of the neighbouring gardens a well in construction had reached the groundwater level at 35 meters depth. For the last time, boys with a donkey cart fllled the water tank in Ives' garden from which the small fruit trees have been watered up to now. Further irrigation will come from the well.
I met the team of well diggers, that arrived to continue work on Ives well, starting at 17 meters depth. In the mean time they dug it out to groundwater level. They will continue with the construction of concrete rings that they will sink into the water bearing layers.
Ives took me to a carpenter, enthousiastic to assist in constructing the pulley and its support over the well. Ideas developed to make a platform as a well cover. On it a person could stand to pull down the rope, running over the pulley. At each end of the rope a rubber bag is attached. The rubber bag, connected to the part of the rope, lowered into the water down in the well will fill up, while the rubber bag having reached the platform is being emptied into a container placed on the platform. From this higher position of the container, water could run through a hose to plant beds and trees to be watered.
I promised Ives to make a scale model of this setup, that he could send to Keur Mousse, to inspire the carpenter and others that now continue work on Ives' garden project.

Sadly nothing came of the plan to instruct people from Oumar's school how to make the NightReader. However bad I felt because of lost time and opportunities and because of my sick body, it felt so good to receive continues kind support from Ives, his family and his friends. Certainly I owe them an effective continuation of support for their projects.

News Sun Jan 19 (2003) -- Wed Nov 13 (2002)
News Tue Nov 12 (2002) -- Fri Sep 20 (2002)
News Mon Sep 16 (2002) -- Thu Aug 08 (2002)
News Mon Jul 01 (2002)