Archive for WOT Blog

Intro activities 2022

Monday, August 29th, 2022 No Comments

The WOT is hosting introduction activities every Wednesday and Thursday throughout the month of September.
Yes, that is a lot of intro activities.
The intro activites are easy to follow and well prepared, you need no prior knowledge and can come by to have a look what the WOT is all about. Interested? Use the signup form below to let us know that you are comming and to join the free dinner (If you so wish).

Sign up here

Wednesday the 7th of September
Terrain tour and marblepump workshop.
This Wednesday we will be giving tours of our terrain, multiple members will be walking around to explain what each contraption or building is and answer any questions you might have.|

After the tours (and dinner) we will be starting construction on marble pumps, each course taker can make their own marblepump and take it home with them afterwards.
Here is the manual we will be following, but you don’t need to prepare anything.

Thursday the 8th of September
Lecture on well drilling.
We will host a lecture on well drilling, and in particular manual well drilling. Different techniques and concepts will be introduced and discussed and of course there will be time for all your questions.

Wednesday the 14th of September
EMAS drilling!
Today we will put some of the learned theory in practice. (or give you a very quick catch up course if you missed last Thursday)
We will be drilling a well by hand using the EMAS method, last year we got to 6 meters. Will we be able to beat that?

Thursday the 15th of September
Project presentation and project night
We will give a short presentation on all the current projects the WOT is working on. Afterwards we will split into groups and work on some of these projects. This is a great way to get to know the practical side of our association and learn where everything is in our workshop.

Wednesday the 21st of September
Normal project night
Today we will continue working on different projects on our terrain and in our workshop. Every project has an assigned member so there is always someone to whom you can ask your questions and who can help you with your project work.

Thursday the 22th of September
Pubquiz “Or is it putquiz?”
Today we will be hosting a pubquiz on our terrain, expect normal pubquiz themes but also questions about development aid etc.

Wednesday the 28th of September
Workshop course
We will be giving a workshop course, you can get experience with different techniques like welding, grinding, cutting, reading technical drawings etc.

Thursday the 29th of September
Team vs. Team challenge
We will be having a buildoff one team agains the other, how creative are you? How well can you translate ideas into working machines using the different tools in our workshop? Will you be te one to win the team vs. team challenge?

Please sign up for an activity if you are interested, it is always possible to withdraw but this helps us estimate how many people (and thus food and materials) to expect.
Signing up can be done here.

Wotters in Kenya

Wednesday, June 1st, 2022 No Comments

A few months ago, two organisations specialized in well drilling training, invited the WOT to join them in Kenya. They wished to reach more people through a YouTube video of the drilling and training process. Two members of the WOT accepted this challenge and travelled to Kenya in May.

The course was focused on water supply for poorer communities in rural areas. The drilling method is designed in such a way that no difficult or expensive tools must be utilised in the process. The wells and boreholes are often a lot safer and more hygienic than the alternatives present in the area. The training stretched across 3 weeks in which multiple wells were drilled. Water tanks, various pumps and DIY solar showers were also demonstrated. People from all over the country, and even some from abroad, joined the course: a huge success!

Training as such, can be found all over the world. Unfortunately, this specific drilling method is used almost only in Bolivia, where the inventor lives. We hope that, through promotion efforts, the EMAS drilling method can be used more often in Kenya. And that the WOT can do our bit in distribution of said knowledge.

Afterwards we made a video on the EMAS drilling method:

Working weekend 1st and 2nd of April

Wednesday, April 27th, 2022 No Comments

After a long winter we’ve organised our first working weekend of the year! With joint efforts, the main goal was to drill a well at the back of the terrain for the new ‘Umoya’ test-setup that will use the earlier posted ‘new gearbox design’ by one of our members. The well was planned to be 20 meters deep with a diameter fitting for a PVC-tube of 125 mm. This seemed quite a challenge since this diameter has not been tried before on our terrain. However, with our EMAS drilling tip extended and filled with good hope whilst wearing warm clothing, we set to work.

Throughout the weekend some of our members posted stories on our new Instagram page to show to the outside world how the EMAS drilling method is used to drill a well and of course to show part of what we do as the WOT. So if  you do not do so already, be sure to follow us on Instagram! A big thank you to all members who worked on the Instagram stories!

In one Saturday we managed to drill to 9 meters in depth, not quite the depth we had hoped for. Next Sunday we set to work with an extra heavy first drilling pipe. Even this didn’t increase the amount of meters per hour achieved, so after lunch a less conventual electric pump was used to pump water into our well, combined with the newly developed rowing machine for lifting the drill pipes up and down.

 Getting stuck on a layer of coarse gravel the depth was eventually settled on almost 15 meters, which is after all quite deep considering the PTB-tower next to the well is even smaller than that. After dinner the PVC pipes have been lifted in and the well was made ready for development and use.Despite the smaller amount of people joining this working weekend because of bad weather conditions and COVID-symptoms we managed to achieve the our main goal. To all members who joined, thanks for all enthusiasm, exhaustive drilling, building a rowing machine for Euros to be jealous of, a great campfire, all the necessary technical advice and, above all, a great time!

Youtube Video – Testing “Free Energy Water Pump”

Sunday, January 9th, 2022 2 Comments

A new youtube video has been published on our youtube channel.

The youtube channel ‘Learn for Life’ has posted multiple videos on a “free energy water pump’. Because we were sceptical whether this pump works or whether the video is fake we decided to build the pump ourselves.

You can watch the video below. Don’t forget to also have a look at the other videos at our channel

Plastic recycling projects – progress

Wednesday, November 17th, 2021 No Comments

Since last year, the WOT has been in contact with HGI, an organisation that focuses on solving the plastic waste problem on small islands in the Moluccas. Several projects have been worked on since then.


First of all a shredder has been made. Most commercially available shredders use rolls with teeth to slowly grind plastic into small pieces. The tolerances on these machines should however be rather small for it to function properly. Often advanced machines are used such as a laser/plasma cutter or parts have to be bought, to fabricate these types of shredders. The idea behind building the shredder at the WOT was to investigate if it would also be possible to create a shredder which requires less precise parts and can be made with widely available tools.

In this case an engine from an electric lawnmower has been used, mounted on a wooden frame and a custom blade was made. The shredder basically resembles a large blender. A mix of plastic waste (mostly packaging waste) was put in the shredder. This was a mix of PE and PP films (such as plastic bags) and harder products from PE,PP or PET.

After some tests, teeth were filed into the blade to decrease the possibility of film winding around the blade. After this adjustment the shredder performed reasonably well. It did not shred material quickly, but, with some help it was able to shred film, which is a difficult material to shred for most shredders. This shredder serves as a proof of concept to show it is possible to shred plastic without an advanced setup. Further research should be done to see if the shredding process can be made more efficient so it takes less time. Also, still some foil winded around the blades, further improvements might mitigate this. If these problems are solved a more generic model (with construction manual) may be designed.

Melting oven

Furthermore a melting oven was designed that can be used to melt the plastic. The molten plastic can then be pressed in a mould to form a product. The oven was designed to work on woodfire. Often electric heating elements are used to melt plastic, but the choice for fire was made because the product was designed to be as accessible to as many people as possible, and the large electricity demands for heating may be a limiting factor for people.

Fire is made on the lowest plate, of which the height can be adjusted. The bottom half of the oven is filled with sand to act as a buffer. This way temperature regulation is more controlled. Plastic is placed and melted in the top half of the oven.

Tests using the oven revealed that it was suitable for melting plastic, but that the temperatures reached were not high enough for melting PET properly. Possibly the buffer region could be made thinner to allow the oven to heat up further, but a more feasible approach is to separate the PET from the PE and PP. Also mixing the plastic when molten in the oven was difficult, the plastic is very viscous and the oven does not allow for great access.


Via HGI the WOT got into contact with Rik Voerman as he had designed an extruder for plastic. This extruder was made such that it would be easy to transport so that people in remote locations can use this machine. It uses a cement mixer that drives a wood auger, while plastic is heated with electrical heating elements. The machine extrudes a lump of plastic that is placed in a mould and pressed together. The extruder does not inject plastic into the mould under pressure as this would require more power and a bulkier setup. The machine is fed plastic pallets or agglomerated plastic film (film made into clumps). Foil is not picked up well by the screw and cannot be processed directly, even if it is shredded.

At the WOT we decided to build this extruder for ourselves. Rik supplied us with the necessary components which were assembled and a simple mould to perform tests with was made on the lathe. The extruder worked well, the molten plastic was deposited in the mould and the mould was closed in a vice. The results were as desired, and the machine was simpel to operate.

Challenges ahead

The extruder performs well at melting and mixing the plastic and it was easy to use. It seems to be a better option for melting plastic than the oven that was made. There are a few things that could be improved however. First of all the extruder is made in the Netherlands and shipped abroad, as it requires advanced machinery to produce. This raises questions about what happens if the machine breaks down, can it be fixed locally? Possible failure and the possibility of fixing the machine will be investigated.

Also the processing of film is difficult, while a significant portion of plastic waste is film. Shredding and agglomerating it is possible, but agglomerators are generally heavy machines that need a very large power supply. These machines may not be accessible to small businesses in developing countries. Research will be done to investigate if it is possible to agglomerate plastic with a smaller machine that requires less power. Also the shredder should be further improved to reliably and quickly shred plastic foils.

Another solution to this problem would be to study what happens inside the extruder and investigate whether the design can be changed such that it accepts film directly.

The further progress of these projects will be posted on this website.

New Youtube Video – Rotary Jetting Well Drilling

Saturday, October 23rd, 2021 28 Comments

A new youtube video has been published on our youtube channel.

The video shows a custom made well drilling method called rotary jetting. It combines a rotating drill head with a water jet. If you are interested also have a look at the experimental setup of airlift drilling and the motorised airlift drilling setup.

You can watch the video below. Don’t forget to also have a look at the other videos at our channel

Overview Introduction Activities 2021

Friday, September 3rd, 2021 No Comments

The WOT will host introduction activities every Wednesday and Thursday this September.
You can sign up for these activities using the following google form: Sign up via Google Forms

These activities will be organised like our weekly association nights (normally every Wednesday) so we’ll gather at the wot around 17:00 and have dinner at about 18:00, afterwards we would normally work on our projects and end the night around the campfire, but for this introduction period we have some activities planned.

-Wed 8 Sept,

Introduction evening, we will give tours of our terrain and workshop and we will be making marble pumps
*A manual for the marble pump (you don’t need to prepare anything) can be found here.

-Thu 9 Sept,

We will host a lecture on well drilling (using manual methods that can be used in development countries), and of-course if you missed the tour on Wednesday there will be an option to be introduced to the terrain.

A lecture on manual drilling methods (2021)
-Wed 15 Sept,

After the well drilling lecture of the previous week we will now actually drill a well using the “Mzuzu” or the “Emas” method.

*these methods will be introduced and explained in the lecture on Thu 9 Sept.

Drilling a well (2020)
Emas drilling (2021)
-Thu 16 Sept,

We will host a presentation on some of the wot’s most prominent projects from the past and discuss our various currently ongoing projects afterwards we will split up into groups and work on some small projects around the terrain.

-Wed 22 Sept,

We invited happy green islands to host a lecture on low-tech plastic recycling techniques.
Two people from happy green islands came to the wot and presented their work and goals, they showed us the website ekoMaluku and discussed technical innovations to localize plastic recycling (so it can be done on small islands).

-Thu 23 Sept,

We will divide the group into teams to play a pubquiz on mostly wot related topics (development techniques, climate, mechanical engineering etc.)

-Wed 29 Sept,

We will continue working on small projects and there will be the change to get involved/help out/watch over some larger projects.

Working on small projects (2021)
-Thu 30 Sept,

We will be giving workshop courses to our new members to introduce them to and familiarize them with the various machines and tools in our workshop.
(Welding, grinding etc.)

On all these days we will be eating together at the wot, and ending the night around the campfire.

Ending the night around our campfire.

You can sign up for these activities using the following google form: Sign up via Google Forms
If you have any further questions please don’t hesitate to contact us.
Want to have a better overview of the wot from the comfort of your couch? watch this video that we made last year:
*The dates and activities at the end of the video are outdated.

Mzuzu Demonstration

Thursday, August 12th, 2021 1 Comment

This June, the WOT organized its first physical activity in a long time! In light with the start of producing a Mzuzu well-drilling set, Henk Holtslag from SMART introduced enthusiastic WOTters to the Mzuzu drilling method in a 1-day course.

With regard to an information request on drilling holes through small rocks and thin layers of stone by the Afundisen foundation, the WOT will built and test its own Mzuzu drill set, suitable for this purpose.

core auger in action

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Core auger in action

The method consists of 3 different kinds of drill bits and a bailer. Drilling the well starts with the core auger, drilling through layers of loose dirt and clay. The auger can be emptied by pushing the contents on a stick dug in the ground. The drilling speed in this process was about 8 meters per hour.

Once the dirt becomes too wet to use the core auger a spiral auger is used, which is cleaned using a special tool to fit in the spiral. Drilling speed was difficult to measure, but a lot lower compared to the core auger. 

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The spiral auger in use

Once the mud becomes too viscous for the spiral auger a bailer is used. This bailer is used within the well casing which will sink deeper into the ground by applying some weight while using the bailer. This is different from other drilling methods which generally place the casing after drilling has finished, using drilling liquids in the process to support the well during drilling.

Start of bailing

The bailer that is used acts as a small bucket with a valve at the bottom, filling with sand by a vertical pounding movement. The bailer is suspended in the well casing on a flexible pipe and is emptied using a bucket of water. Once more drilling speeds were difficult to measure, but were even slower than while using the spiral auger.

As a last part the bottom of the well is sealed by dropping a small plastic bag filled with cement into the casing. 

During drilling with augers a stone punch, fixed on the same pipe as the two augers, can be used to disintegrate small rocks and thin layers of stone to reach the water aquifer. However the soil on the WOT terrain contains neither, so this has not been practiced.       

A big thank you to Henk Holtslag for displaying the Mzuzu drill method to the members of the WOT! Once we have finished building our own Mzuzu drill set we will start with more tests to get experienced and find more accurate drilling speeds, depths and the possibilities of using a stone punch.

New Youtube Video – Amanzi Water Pump

Sunday, August 1st, 2021 No Comments

A new video has been posted on our youtube channel. The video shows how to construct an amanzi water pump. This is a pump made from HDPE pipes. Therefore it is flexible and lightweight.

You can watch the video below. Don’t forget to also have a look at the other videos at our channel.

Update gearbox design

Sunday, June 27th, 2021 1 Comment

Since the last post about the new windpump gearbox a lot of progress has been made. In this blog, we will discuss some of the findings during the process. Also, some important changes are made to the design which will be discussed. Starting from the last blog post about the gearbox the test installation is finalized from the first design.


One of the first major changes to the design is the type of bearing used. At first normal bearings are used for which a housing is made and welded to the gearbox casing. As could be expected the alignment of the bearings was rather difficult. When the bearings were installed it was not possible anymore to change the distance between the two gears.

Both problems are solved by making use of flanged bearings which have a couple of advantages:

  • Easy to replace.
  • Axle can be fixed in place, so no additional parts are required.
  • The ability to compensate for some misalignment.

First run

In the video below the first rotations of the gearbox are shown including the counting of the strokes. The transparant window is only for inspection purposes during the test phase of the gearbox.

Now all the main components are working the gearbox is painted and the last details are worked out such as preventing the weight from rotating during yawing.

Steel cable

At first a steel cable is used to transfer the rotating motion of the rotor into a translating motion. A 6mm thick steel cable is used, however this cable snapped after 59.535 strokes due to the small pully (60mm diameter) used to guide the cable. According to the steel cable manufacturer, a pully of a steel cable should have a minimum diameter of 20x the cable diameter. This would result in a pulley with a minimum diameter of 120mm, within the gearbox there is no space for such a pulley.

A smaller steel cable of 4mm in diameter is used in combination with a slightly larger pulley (85mm). This cable snapped after only 19.334 strokes, a final test is done with the 6mm cable in combination with the larger pulley. This helped a bit, however the cable still snapped after 69.591 strokes.

Another problem with the steel cable is that if the tension by the weight is released it will immediately ‘jump’ of the guide pulley. Whenever the gearbox is started after that the cable is damaged, which is not preferred if the gearbox is up a windpump.

Solution: Instead of the cable, a chain is used in the newest improvement of the gearbox. This new configuration has done over 120.000 strokes without problems.

Test results

Based on the previous blog post about the gearbox several things where tested and monitored during the manufacturing and working of the test setup:

  • Effect of yawing on the cable: The weight is fixed and cannot rotate as we expect that the cable/chain will fail before the pump starts rotating in the borehole. Therefore a coupling is made which will account for the yawing motion of the windpump head. This connection can also be used as a safety feature if the pump will get stuck in the borehole for instance. –> this coupling is working well and will be discussed in a later blog.
  • Ease of manufacturing: As discussed before, alignment of the bearings appeared to be difficult. With the new flanged bearings, the tolerances on the different shafts can be less precise.
  • Oil consumption: Oil will leak through almost every hole present in the gearbox, so the correct type of seals have to be used where the axle goes through the gearbox housing and where the gearbox is bolted to the tower head. Most of the oil will leak via the cable/chain through the tower pipe if the cable/chain is touching the main gear. This can be easily prevented by making the gearbox housing a bit bigger.
  • Failure modes: The main failure mode appeared to be the snapping of the cable, this is solved by using a chain instead of the cable. To find more failure modes the gearbox has to be tested with contamination like sand and water from outside the gearbox.
  • Maximum load: The maximum load and the weight of the weight is not determined yet. It is assumed that the maximum load is currently limited by the motor simulating the rotor.