Lacey Green Windmill, Buckinghamshire

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The pictures on this page show the machinery in the CAP, then each of the four floors of the mill, starting at the top with the DUST FLOOR, then the BIN FLOOR, then the STONE FLOOR, and finally the MEAL FLOOR, which is the basement of the mill.


The cap is the part of the windmill that automatically rotates to enable the main sails to face the wind.  The wind shaft is a huge piece of timber across the centre of the cap.  Protruding from the front of the cap, and on the end of the windshaft is a metal canister which holds the main sails.  Inside the cap, and on the windshaft, is a large wheel called the brake wheel.  To carry the drive down the mill, teeth on the brake wheel engage with teeth on another wheel called the wallower.

The brake wheel with its spokes radiating from the wind shaft. The brake shoe is at the top of the wheel, it runs right around the brake wheel. The main sails are just outside the doors in the centre of the picture.


Dominant on the top floor is another huge piece of timber, the vertical main shaft which travels down three floors of the mill.  On the top of the main shaft is the wallower whose teeth engage with the brake wheel, transferring power (when the main sails are turning) down the mill to the machinery on the floors below.  The main shaft and the wind shaft are oak, as are the spokes of the brake wheel and the wallower, but their rims are elm, and their teeth hornbeam.  They all probably date from around 1650.  Also on this floor are two bins or hoppers which store grain and flour for the two machines on the Bin Floor below.


The main shaft in the centre of the windmill.


The wallower at the top of the main shaft.


Power is taken off the main shaft by a metal wheel which has been made in two sections to clamp around the wooden main shaft.  The wooden teeth mounted on this wheel are beech wood.  There are three pieces of machinery on this floor.  Firstly, the sack hoist is used to haul sacks of grain or flour up the mill.  Secondly, a smutter which is a machine used for cleaning the grain before it was ground.  Thirdly, a bolter which is a sifting machine used for grading the flour.  The Smutter and Bolter at Lacey Green are 19th century machines that were brought from another mill during the restoration, to replace similar ones that were beyond repair.  Also on this floor are two bins or hoppers which are loaded with grain for grinding on the Stone Floor below. 


The metal drive wheel (with wooden teeth) for the 3 machines on this floor.


Drive belts, from the days before Health and Safety Regulations.


On this floor is a large beam which supports the weight of the main shaft.  Power is taken off the main shaft via another very old wheel called the Great Spur Wheel.  Much smaller cog wheels called stone nuts can be engaged with the teeth on the Great Spur Wheel to drive either of two pairs of mill stones.  One pair are Derbyshire Millstone grit, used for coarse grinding of oats or barley for animal food.  The other pair are French Burr Stone, used for the finer grinding of wheat into flour.


The Great Spur Wheel in the centre, with two stone nuts (small cog wheels).


The Millstone grit stones.


Down on this floor, which is below ground level, there are massive timbers around the middle of the floor which support the millstones on the floor above.  Between these timbers there are two flour boxes or bins to catch the products being ground by the millstones.  The underneath of the bed (or fixed) millstones can be seen above the flour boxes.  The weight of the top (or runner) millstones is carried by horizontal timbers on this floor, where adjustments to the gaps between the millstones would be made.

Sacking chutes descend into the two flour boxes in the centre of this floor.


Further details of the interior and the machinery in the mill are in the Booklet on the windmill.  Please click here for further details.

Thank you for looking at

This page was last updated on 30th March 2012.

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