FROM CHORD SECTIONS TO THE BLADE SKELETON / ORIGINAL WORKSHOP IMAGES
01 / THE DESIGN TOOL
Start with BladeCalc.
BladeCalc helps you explore the relationship between blade radius, blade count, tip-speed ratio, wind speed and estimated turbine performance.
IN THE LIVE CALCULATOR
Choose your design inputs.
Select a 2- or 3-blade configuration.
Set the radius and test wind speed for the design you want to compare.
Review the displayed power and RPM; adjust TSR if appropriate.
Check the displayed plan range before proceeding. Advanced options are provided in the calculator's expert menu.
The historic guide assumes chord-section PDF plans are available. Plan ordering and free-download behaviour in the current calculator should be checked there; this guide does not promise a working PDF export or current pricing.
BladeCalc and chord sectionsOriginal guide illustration.
02 / PRINTED AIRFOIL CHORD SECTIONS / ORIGINAL STEPS 1–3
Begin with the printed cross-sections.
Each chord template represents a blade profile at a particular radius along the span.
The original starting guide described free sample chord sections for 2- or 3-blade wind turbines, using a radius of 0.70–0.80 m and a tip-speed ratio of 7–8. Those are historical trial-range descriptions, not confirmation of what the current calculator can download. It also referred to custom PDF plans and introductory prices that may no longer apply.
Print the BladeCalc plans and cut out each chord section.
Paste the shapes onto balsa at least 3 mm (0.12 in) thick and cover the entire piece with super-glue adhesive, as described in the source.
Cut out each balsa section using a scalpel.
Cutting chord sectionsOriginal workshop photograph and annotations.
03 / HUB, ROOT AND BLADE SKELETON / ORIGINAL STEPS 4–10
Assemble the chord-section skeleton.
A central support aligns the airfoil sections at their planned positions before the blade surface is formed.
Make a hub from wood with a thickness to match section 1.
Create a root from a solid piece of plastic or sheet metal, with a thin rod to align the crosshairs drawn on each section.
Glue the root into the hub.
Position each balsa section at the radius shown on the plans and glue (or silicone) them in place.
Hub and root detailOriginal technical drawing.Chord-section alignmentOriginal isometric construction diagram.Completed skeletonOriginal workshop photograph.
Cover the skeleton using fibreglass gel-coat or epoxy.
Glue acetate sheet to the top and bottom of the sections.
Seal the acetate sheet with aluminium tape or waterproof tape.
Covering the airfoilTwo-piece acetate-sheet diagram.Sealed blade surfaceOriginal workshop photographs.
04 / TWO-PART MOULD / ORIGINAL STEPS 11–16
Form the two mould halves.
The source illustrates a clay-bordered plaster-and-gauze casting process, with fibreglass alternatives noted.
Make a border to support the casting mixture. Moulding clay is used in the original example; the guide names plaster and gauze, plaster/fibreglass, or fibreglass and resin as alternatives.
Fill the mould with the casting mixture and allow at least 48 hours to dry, as recorded in the historical method.
Cast the opposite side to create the second mould half.
Reinforce the outside with fibreglass if the mould is too thin, before separating it.
Separate and sand the mould halves once dry.
Apply mould-release wax inside the mould. The original also mentions hairspray or shellac as alternatives.
Supporting the castingOriginal clay-border photograph.First mould halfOriginal plaster-and-gauze process.Completing the mouldOriginal moulding photographs.
05 / FIBREGLASS BLADE / ORIGINAL STEPS 17–20
Lay up, release and finish.
The original guide finishes with fibreglass lay-up inside the two halves and the release of the blade.
Line both mould halves with at least four layers of fibreglass matting. For a 0.7 m (2.30 ft) blade the source gives at least 375 g (13.23 oz) of resin per side.
Clamp the two halves together when the resin reaches its gel point.
Separate the mould halves after 72 hours, according to the original example. The source mentions dissolving stuck plaster with dilute vinegar or hydrochloric acid; this is historical process information and not a substitute for chemical-safety controls.
Sand the blade smooth and fit a solid hub piece.
Laminate sequenceOriginal process diagram.Blade releaseOriginal four-part illustration.The finished bladeOriginal result and release photograph.
Source figure note: the historical fibreglass illustration labels a 250 g resin quantity, while step 17 specifies at least 375 g per side for a 0.7 m blade. The source does not reconcile those values; neither is a validated laminate schedule.
The source describes a workshop demonstration, not qualification testing. It does not provide laminate engineering, fatigue-life evidence, hub fastener design or proof testing for safe operation.
WARLOCK ENGINEERING / BLADECALC
Back to the design.
Use the calculator to compare blade radius, blade count, TSR and estimated operating performance. This guide preserves the original illustrated manufacturing example as context for the chord-section plans.
This starting guide adapts the historical Wind Turbine Plans: Starting Guide from the original Warlock Engineering site. Original figure files are retained, and the example dimensions, quantities and manufacturing steps remain identified as historical source material. The calculator itself is unchanged.
