Thaka.AiReviewed 16 October 2026 · schematic not to scale
A small supervised model to compare fins, flow and lifted load before considering outdoor hydro. It demonstrates mechanical work, not a household electricity system.
- 1Consistent measured pouring flow
- 22 L bottle with fins and supported dowel
- 3String on the axle; supervised low load
- 4Known small mass; measure lift height and time
Site and operating requirements
- Survey net head, usable seasonal flow, flood level, debris and legal access. Select a design for that measured resource.
- Obtain complete shaft, bearing, mounting, guard and electrical drawings. A photograph is not a tolerance or load specification.
Tools and measuring equipment
- Tape/level and safe survey tools, timer and measured collection vessel for suitable small flows, tachometer and rated load/meter set; workshop tools follow the full drawings.
Output and operating conditions
Measure rpm and the height of a small lifted object. No electrical wattage is published for this classroom route.
Independent summary of the University of Colorado Boulder Water Power activity. Actual bottle and fin measurements must be recorded; there is no universal fin cut list.Parts, quantities and dimensions
| Part | Quantity | Specification / dimensions |
|---|---|---|
| Clean bottle and dowel axle | 1 each | 2 L bottle; approximately 6.35 mm wooden dowel, longer than the bottle so both ends can be supported. |
| Fins, tape and stable supports | 1 set | Water-resistant fins, matched axle holes and a catch tray; measure fin width and spacing. |
| Water and measurement tools | 1 set | Pouring vessel, timer, ruler, string and a small known mass; adult hole-making tools. |
Preparation and component checks
- Read the complete linked method, mark its edition, and create a measured component list and a labelled sketch before starting. Keep experimental changes separate from the published procedure.
- Prepare the work area and inspect every component. Run the lowest-risk dry or unpowered check before water, heat, moving parts or crop material are introduced.
Procedure
- 1
Measure the bottle, mark the cap and base centres, and have an adult make aligned axle holes. Smooth all edges.
- 2
Fit the dowel, attach evenly spaced fins, and support both ends over a catch tray so the wheel turns freely.
- 3
Mark one fin. Pour a consistent measured water volume from a fixed safe height and count turns over a timed interval.
- 4
Attach a light string load only with adult supervision; keep fingers and loose items clear. Measure lifted height and time.
- 5
Change one fin or load variable at a time, repeat under the same flow, then drain and dry the model.
Safety and inspection
Keep this model on a stable table with a catch tray and no mains electricity. Adults handle cutting; do not transfer classroom supports into a stream.
Verify the result
RPM = 60 × turns / seconds. Mechanical work = mass × 9.81 × lifted height; divide by time for average mechanical power. Include measured units.
Measurement log
- Drawing revision, measured dimensions, resource inputs, speed/flow, loaded output, trial duration and every observed fault. Mark unknown values as unmeasured.
Maintenance and repeat checks
- Inspect and clean after each trial following the source method. Record wear, contamination, leaks or loose components; do not restart until the cause is corrected.
- Use the source’s service intervals and replacement limits. Recheck the result whenever a component, material, input condition or method changes.
Troubleshooting
- No output, abnormal heat, noise, vibration or leaks
- Stop and isolate first. Check the documented input, load compatibility, alignment and connections; keep guards fitted and refer specialist systems to their installer.