The Waterwheel Project V1.0

Introduction

Motivation:

In montaineous regions like the Himalayas, access to reliable electricity remains a challenge for many communities. Despite substantial hydropower potential in these regions, a significant portion of its population still lacks consistent electrical energy. To address this issue, a collaborative effort between researchers, craftspeople, and operators has led to the development of a modular low-tech hydropower solution using overshot waterwheels. This project aims to provide a simple, robust, cost-effective, and locally accessible way to generate electricity for off-grid communities.

Local Collaboration:

The project involves close collaboration with local craftspeople, local researchers, and local operators. In particular, the combination of different expertise and experience contributes to the success of the waterwheel concept. The goal is to foster knowledge exchange and empower local communities to build, operate, and maintain these systems independently.

The project was initiated by Stephan Baur.

The first real pilot system was built and implemented by Johannes Eisner in Nepal with local craftsmen.

Since 2023, Michael Erhart has been the main person responsible for the project. Michael Erhart collected very useful and also new experiences during the construction of a system with local people in India. Based on these findings, Michael Erhart further developed technical details and the manufacturing (for example with laser-cut) of the waterwheel, particularly for the conditions in India. Details on the updated version of the waterwheel and further additional information can be found in the article "The waterwheel project V2.0" from Michael Erhart. This article here for the original version of the waterwheel will no longer be expanded or adapted (page retired).

Prototype and Future Plans:

Prototypes have been developed and tested in Germany, Nepal and India. These prototypes serve as a foundation for continuous improvement and development. The project aims to establish a repository of open-source technical details and manufacturing instructions for public access, allowing individuals and communities to build and test their own system.

Electricity Generation:

Depending on the dimensions of the modular waterwheel, the system can generate between 100 and 1000 W of electrical power. This capacity is sufficient to provide lighting, power small appliances, and potentially reduce reliance on conventional fuels for cooking and heating. The system presented on this page is a stand-alone system. An asynchronous machine with gearbox can be used as a generator, which can supply the consumers (230 V AC) directly. 

Video clip: From different prototypes to the first pilot system.

Before embarking on the construction of the modular waterwheel using this tutorial, it is essential to note that this guide is intended for individuals who possess prior experience in working with metal and are familiar with workshop tools and procedures. The manufacturing process involves cutting, drilling, bending, and assembling metal components, which require a certain level of skill and knowledge to ensure safety and precision. The instructions roughly describe how the waterwheel can be made using common and very simple tools - such as those available for example in Nepal. The following steps describe and illustrate how to build the waterwheel from start to finish. The selection of a suitable generator and the correct connection of the generator are not covered in this article.

Disclaimer:

The information provided in this tutorial is intended for educational and informational purposes only. The authors do not assume any responsibility for any harm, injury, or damage that may arise during the construction, assembly, or operation of the modular waterwheel or its associated components. All activities described should be carried out with the utmost care and attention to safety protocols.

By proceeding with this tutorial, you acknowledge that you are responsible for your actions and safety while working on the project. If you are unsure about any aspect of the process or lack the necessary skills, it is advisable to seek assistance from experienced individuals or professionals. Your commitment to safety and responsible craftsmanship will contribute to the success of your waterwheel project and the realization of its benefits for renewable energy generation.

Tools and material needed for this step:

• Cutting tools (metal scissor or angle grinder etc.)
• Saftey gear (gloves, googles, ear protection)
• galvanized or stainless steel sheet:
• 0.5 - 0.8 mm thickness
• 2 pieces of 4 x 8 feet for 12 modules

Step 2.1: Preparing the Sheet

Place the metal sheet on a clean and safe working surface. Refer to the provided picture to visualize the size and form of the module you're creating. Ensure you have all necessary tools and safety gear at hand.

Step 2.2: Cutting the Buckets

Using your cutting tool, carefully follow the dimensions marked on the metal sheet. These cuts will shape the buckets that capture the force of water to generate power. Precise cutting is essential to ensure proper water flow and energy efficiency.

Tools for this step:

• Hammer
• Center punch
• Drill machine
• 9 mm & 3 mm drill bit

Step 3.1: Punch Marking and Drilling

Using a center punch and a hammer, create punch marks at key locations. These punch marks indicate where holes will be drilled and cuts will be made. More important dimensions are the one in the box in the provided picture. More important because these will define the size of the module, while the others are only flaps needed for riveting in later steps where it's not as crucial.

Drilling the 3 mm holes, indicated by an "X" in the picture are a crucial step that reinforces the strength of your water wheel module, preventing stress concentration and potential tearing when bending the metal sheet. The carefully placed holes contribute to the overall durability and reliability of your module, ensuring it stands up to the rigors of its intended purpose.

Bending the metal without holes at the corners could potentially lead to tearing, which could significantly reduce the lifespan of the module.

Step 3.2: Further Drilling

In this crucial step, you'll drill 9 mm holes at specific positions indicated by small circles and dimensions in the provided picture. These holes serve as an integral part of ensuring the structural integrity when assembling the module. Again the more important measurements are boxed in the drawing.

Tools for this step:

• Cutting tools (metal scissor or angle grinder etc.)
• Prepared sheets
• Pen or scriber

Before proceeding with the bending process, it's essential to perform a fine cutting step that ensures the sheets won't obstruct the bending and helps maintain the structural integrity of your water wheel module. This step involves precise cuts at specific angles, indicated by dimensions in the drawing.

Mark all postions with a pen before starting cutting.

Begin the cutting process, making sure to align the cutting tool with the prior drilled 3 mm holes. It's crucial to cut exactly to these holes to avoid any tearing or damage during the bending process.

Slowly and steadily guide the cutting tool along the marked lines, ensuring a smooth and accurate cut.

Once all cuts are made, inspect the edges to ensure they are clean and free from any rough or jagged areas. You can use a file or sandpaper to smooth out any sharp edges if needed.

If you don't have a protactor for the 60 degree angle at hand, follow the DIY instructions for the 60 degree template provided in the drawing. This will make your life a lot easier cutting the whole lot.

Tools and Materials Needed:

• Bending machine (sheet metal brake)
• Hammer
• Protactor

Now that the fine cutting step is completed, it's time to move on to the bending process. Proper bending is crucial for forming the metal sheets into the required shape for your water wheel module. Follow these instructions carefully to achieve accurate and effective results.

Begin by positioning the metal sheet in the bending machine (sheet metal brake), ensuring it is aligned correctly and securely held in place. Depending on the type of bending machine used you have to pay special attention to the order in which you bend the edges to ensure you can properly place the sheet in the machine for the remaining steps. Experience has shown that the order indicated by the numbers on the edges in the picture works very well.

Proper bending is essential for creating the correct shape for your water wheel module. By following the indicated angles and the specified bending sequence, you'll ensure that the metal sheet takes on the necessary form without any hindrances or inaccuracies. With the bending step successfully completed, your module is well on its way to becoming a sturdy and reliable component of your water wheel system.

With the manufacturing process complete, it's good practice to perform a thorough inspection to ensure that all parts match the specifications and appearance shown in the picture.

Examine the edges of all components. Ensure that they have been properly deburred. Use sandpaper or a file to gently smooth out any sharp or rough edges. Deburring is essential to prevent injuries when assembling the cells from the modules.

Correcting fine deviations at this stage will save you a lot of time during the assembly process. It's essential that all modules are as uniform as possible the ensure the final wheel will be as balanced as possible guaranteeing a symmetrical wheel to maintain a smooth rotation.

Tools and Materials Needed:

• Drilling machine
• 4 mm drill bit
• Rivet gun
• 18 x 4 mm rivets
• 2 x screw clamp ( C-clamp)

Now that you have prepared the individual components, it's time to assemble them into a cohesive module. This step involves precise alignment and the use of screws clamps and rivets to create a robust structure. Follow these instructions carefully to successfully assemble your water wheel module:

Begin by arranging the prepared components according to the picture provided. Pay close attention to the alignment of edges to ensure a perfect fit. Achieving accurate alignment at this stage is crucial for a well-constructed module and a smooth assembly of the wheel in the next step

Once the parts are aligned, use screw clamps to securely fix them in place. Position the clamps on opposite ends to hold the components tightly together. During the riveting process, apply consistent pressure with the rivet gun to ensure that the rivets create a secure and gap-free connection between the parts. Gaps between the parts will lead to a leaky module and affect the efficiency of the water wheel.

Refer to the provided drawing to determine the approximate locations for the 4 holes needed for riveting. Mark these locations on the components using a pen or a punch mark. Using a drilling machine, carefully bore the 4 holes at the marked locations. With the holes in place, it's time to rivet the two parts together. Insert the rivets into the holes as shown in the picture.

Continue with the two side panels just like before, placing the holes as depicted in the drawing.

The final waterwheel cells should now look like in the picture.

Now that you have successfully created the individual modules, it's time to assemble the final waterwheel by carefully combining these modules. This assembly process requires precision and attention to detail to ensure a well-balanced and smoothly rotating wheel. Follow these steps for a successful assembly:

Tools and Materials Needed:

• Prepared modules/cells
• Protactor
• Screw clamps ( C-clamps)
• 24 x M8 screws (20 mm length)
• 24 x M8 nuts
• 48 x M8 washers
• Tools for screwing and nut fastening ( 2 x 13 mm wrenches )

Step 8.1: Rough Positioning of Modules

Begin by sliding the prepared modules into one another like shown in the picture. As you continue inserting modules, you'll gradually form the circular shape of the wheel. Pay close attention to ensure that the modules are aligned and fit snugly together.

Step 8.2: Fine Adjustment for Balance

With the modules in rough position, it's time for the fine adjustment process. This step is critical to achieve perfect balance and a smooth rotation. In the outer holes of the modules, insert M8 screws with a length of 20mm. Along with the screws, place M8 nuts on the opposite side.

Important: Do not fully tighten the screws and nuts at this stage. Leave them slightly loose to allow for adjustments.

The inner angle of each module, as indicated in the provided picture, plays a crucial role in positioning the chambers. For example, if your wheel consists of 12 cells, the inner angle should be adjusted to 150 degrees.

With the M8 screws and nuts loosely in place, carefully adjust the angle and positioning of each module. This step requires patience and precision to achieve a perfectly balanced and round wheel.

Step 8.3: Final Tightening

Once you are satisfied with the fine adjustment and the wheel's balance, proceed to tighten all the M8 screws and nuts. Use the appropriate tools for screwing and nut fastening.

Tighten the screws evenly and with consistent torque to maintain the balance achieved during the fine adjustment.

Step 8.4: Flipping and Repeating

Now that the wheels is perfectly round and tightly held in place by the screws it time to carefully flip over the wheel and repeat steps 8.2 and 8.3. This will be a lot easier then before since the wheel should already be nicely in position.

With the wheel assembled, balanced, and outer screws tightened, it's time to proceed with drilling holes for the inner bolts. This step is crucial to ensure that the individual modules are securely aligned and held together within the wheel. Here's how to accomplish this task:

Tools and Materials Needed:

• Assembled waterwheel with outer screws tightened
• Pen or punch mark
• 9 mm drill bit
• 4 mm drill bit (used previously)
• Drilling equipment
• 24 x M8 screws (30 mm length)
• 24 x M8 nuts
• 48 x M8 washers

Step 9.1: Marking Hole Positions for Alignment

Extend the inner edges of one module that slide into the other. Also, locate the hidden edges of this module inside the other module from the top.

The objective is to create holes that align the two corresponding edges of adjacent modules, effectively fastening them together. This alignment contributes to the overall stability and integrity of the wheel.

Using a pen or a punch mark, mark the positions for the holes on both edges. Make these marks exactly 15 mm from each side of the created lines as shown in the picture.

Step 9.2: Drilling the Holes

To ensure accurate drilling, use the 4mm drill bit from the previous step to create a pilot hole at the marked positions. This pilot hole will help guide the larger 9 mm drill bit and prevent any potential drifting during drilling.

Now, switch to the 9mm drill bit and carefully drill the holes at the marked positions. Make sure to maintain a steady hand and consistent pressure while drilling.

Step 9.3: Repeat for All Modules

Repeat the marking and drilling process for all the 12 modules within the wheel. Each module should have corresponding holes that align with adjacent modules.

Consistency in hole placement and alignment is essential to maintain the balance and stability of the entire wheel and ease the assembly of the spokes to mount the wheel on the shaft in the following steps.

In the final step, the finished modular waterwheel is mounted on a suitable shaft. Different methods are possible for this step and depend in specific on the possibilities and available materials and components. The images and drawings are to give an impression of how the last step was realized on already implemented prototypes.  

The method described here uses only cut pieces of flat steel and components from the industrial sector (gearwheels and bearings). The spokes (inner wheel) are manufactured individually for each wheel size. The flat steel pieces are cut to size and bolted together. The adapted gearwheels enable the inner wheel to be fixed simply and robustly to the shaft. Commercially available standard pillow blocks are used as bearings, which are mounted on a suitable base structure, for example made of steel. The coupling between the shaft and the generator with gearbox can be made very well with a claw coupling. Long-term experience has shown that this type of coupling satisfies all requirements and also compensates any imperfect positioning of the components. 

Detailed instructions and alternative methods for this final step are provided on the page "The waterwheel project V2.0". This page also provides guidance on selecting a generator. In addition, further instructions, diagrams and specifications tailored to various wheel sizes are provided on this page, for example to facilitate the construction process.