Roller development

Sat Oct 18 (2003)

Prototypes: strips, rings, disks

The test rig of the rope pump has many new components. In fact only the electric engine, its drive disk and the big two meter diameter wheel, that it drives remain from the first setup. As the big wheel is not round at all (it has 12 corners), it needs a roller to keep the tension on the rope steady, specially the unloaded part, moving back to the electric engine.
In the old setup a sort of lightweight pulley folded from thin aluminum sheet did the tensioning. This worked fine, but the pulley was to difficult to make.

How the strips fit into the disks

Together with Bram de Vries I tried to simplify the making of this tensioning roller. We started out with a cylinder of bamboo slats, woven into a strip (left in picture). We found this too heavy and side ways flexible. For the bearings we had a woven construction in mind. Sideways stability was achieved with less bamboo by tying it zigzag on two rings wound from wire. Stability was perfect, but the woven bearing was difficult to make. (middle position, woven bearing removed).
Amazingly easy it proved to be to insert the bamboo sticks in a zigzag way into disks cut from a bucket. Six small square holes and an shallow slot in the bamboos did the trick. The lower picture shows this detail
Puncturing the disk in the middle with a piece of wire results in the creating of the bearing as well as of the axle.

Games with heat and air

Sun Oct 12 (2003)

Mail contact with Sasha Mrkailo, Serbia brought me to this link on small gassifying woodstoves:
First of all it shows the feasability of the idea of forced draft through the oven, as tests show. This encourages, as Demotech explores this principle in experimenting with the Brick Stove.
Second it shows how helpfull it is when information exchange really centers on the issue at stake. It saves everybody a lot of valuable time.
The picture indicates how the draft through this small stove results in gassifying wood and burning this gas in the top part of this stove. It looks like a very smart game with heat and air. How it works is explained in this article.

Layout test

Sat Sep 20 (2003)

Why *This is a layout experiment to find out how the layout should be of the listing of the records in the category page. I want to see how it looks if I use the same method as with making the layout of News. so please do not look at the text that is just a dummy
* Progress within poverty depends on improving conditions for education for 1 billion students world wide.
* Poverty reduces the capacity of young people to study at home. Cramped interior space used by too many and insufficient interior lighting are negative factors to be overcome.
How * Education ask for time to study. Four hours each day after sunset can be used for study with a proper reading light, called the NightReader, that fits conditions of poverty.
* A box with batteries to which two LED's are attached is placed on the page or paper to be read. The LED's only illuminates a few lines of text, not attracting insects.
* A NightReader can be constructed with the help of a construction manual by its user or people around from local scrap material.

Second layout test

Sat Sep 20 (2003)

Why *This is a second layout experiment with a smaller picture, to find out how the layout should be of the listing of the records in the category page. I want to see how it looks if I use the same method as with making the layout of News. so please do not look at the text that is just a dummy
* Progress within poverty depends on improving conditions for education for 1 billion students world wide.
* Poverty reduces the capacity of young people to study at home. Cramped interior space used by too many and insufficient interior lighting are negative factors to be overcome.
How * Education ask for time to study. Four hours each day after sunset can be used for study with a proper reading light, called the NightReader, that fits conditions of poverty.
* A box with batteries to which two LED's are attached is placed on the page or paper to be read. The LED's only illuminates a few lines of text, not attracting insects.
* A NightReader can be constructed with the help of a construction manual by its user or people around from local scrap material.

Getting ready for Cameroon

Sun Sep 14 (2003)

A NGO in Cameroon contacted Demotech by mail. They had a sincere interest in many of the designs, related to rural as well as to urban conditions. It would be nice to be able to serve these people better. Still not even the old manuals of the rope pump are properly visible in 'Make It'. It just is an amazing amount of work, taking a amount of time destructive for other projects that should be done as well.
However on behalf or these people in Cameroon I organized the 'Make It'-manual for the construction of the Bathroom/Toilet unit better. This became possible after the reorganization of the images was done. Also my answer to the demand of Leonora and Petz for a bullets in 'How' and 'Why' extends now into 'Presentations'.
The demand of these intern girls resulted into a sceme to present a few short items marked with bullets in 'Why' and 'How' , these two fields as presented for each record in the 'Category' page. Together, these items can be read as a summary that is covered more extensively in "Why' and 'How' as visible in the design page. This proves to be a workable structure.
The same structure now applies also to the first page of a presentation, such as Manual for the Bathroom/Toilet unit. Each chapter of such longer manuals is in short described in one sub-record of 'Presentations', hyper-linked to this page. I made sure the chapter descriptions together could be read and understood as a summary of the total manual.
The net result should be easier navigation through Demotech's website. Our new contact in Cameroon is the first who can tell us if this works. I sincerely hope they will use our discussion page to air their findings!

How to find out what works and what does not work? Only to try gives an answer. Around 1986 Demotech tried to speed up instruction around improved wells and water pumps in Ghana with the Mobile Training unit.
We bought a DAF-truck to get going .. but got nowhere. No support or support that halfway redoing the electric wiring thought of something better. Now the DAF-truck at last is on the road again. I gave it away to a nice guy in exchange for his promise that he would support Hanna's Senegal project with some free transportation when needed.

Drifting apart, creeping together

Mon Sep 08 (2003)

Dull administration

Wed Aug 27 (2003)

This website asks for an enormous amount of pictures to clarify its content. Hundreds are already uploaded to the computer of Demotech's provider, AS-Hosting. Many thousands will follow. Many recent mistakes make it clear that a simple and clear system is needed first to size, then to name and finally to store the images.
Coordinating work with volonteers like Leonora and Petz, who produced a flood of most beautiful photo's, also ask for a system that is very easy to explain, as such workers assist Demotech only for a short time, be it days or weeks.
Today I cleaned up only the beginning of the mess that came into being as such an administrative system had not yet been perfected. This is the work drill from now on:

Welding wood, checking the manual

Thu Aug 14 (2003)

Rogier is now familiar with the technique of welding wood. When I asked him to set up the construction of the new toilet seat, he had no difficulty in selecting the right size nails, width and thickness of sheet metal, and then a good position for the wooden parts to fit nicely together. He does the nailing swiftly, the sheet flows around the wood, and there are no sharp bits sticking out.
Yet this is only the eighth joint he has welded. Does this prove that the system of Welding Wood does what it promises: offering real strength in connections between wooden parts, without the need for professional abilities?
The two interns Leonora and Petz checked it for themselves. They found the welding OK, but had several remarks on the effectiveness of the manual.
I will discuss these with the girls today and make the appropriate changes.

Make it! See it!

Sat Aug 02 (2003)

The sunny side of the NightReader

Fri Aug 01 (2003)

The interns Leonora and Petz now focus on the NightReader. They have another two weeks to go and want to get this design job done. They plan to use their experiences with this design in the presentation they are expected to deliver at their school. However it is still not clear how a number of problems should be solved.
Leonora and Petz discovered two fundamental new approaches for the construction of the box that houses the three batteries of the NightReader. Both ideas help to make the instruction package to make the NightReader thin enough to be sent to users by post in an envelope.
One is to link all parts of the box -if sheet metal is used- with a hinge-like construction so that is is completely collapsible. We have still to explore the possibilities this method offers.
The other approach does away with sheet metal. It makes the box from two layers of cloth, sewn into rectangles made stiff with inserted bits of carton. This approach is promising: easy to make on a sewing machine, looks nice, easy to decorate. But as yet there is no answer to how a number of parts will be joined.
I trust that the continuing experiments, by the two girls, in our sunny garden will provide that answer.