2021 Restoration Update 8

There is still no news from the Department of Public Works in Pretoria, and the workshops fabricating our new wooden machinery were closed over the festive season.  But since then, Mike Sutten at Solid Engineering in Grabouw has made good progress on the big Brake Wheel and the Lantern Pinion.

The Brake Wheel & Lantern Pinion

Just to remind you what these two items do, here is a sketch again.

The Brake Wheel is turned by the Windshaft with its four sails attached.  Square cogs sticking out of the Brake Wheel engage with rungs on the Lantern Pinion, which is fixed to the top of the Vertical Shaft.  That rotating shaft is fixed to the upper of two millstones on the first floor of the Mill, and the supply of wheat is ground to flour (more correctly, meal) between the turning upper millstone and the stationary lower millstone.


Here is the brake wheel at an early stage of assembly:
The next step was to round off all the outside corners, creating plenty of sawdust on the floor:

The following step was to drill sqare holes to fit the cogs (or pegs) into the Brake Wheel.  Anyone familiar with a bit of home carpentry will know that it is not easy to drill square holes!  But Mike has made up a special mortising tool for this purpose, and here it is in action:

The sketch earlier shows that the rungs on the Lantern Pinion are held in position between a pair of upper and lower discs.  The first photo below shows the beginning of one disc.

The next photo shows both discs assembled, using two layers of wood for each disc  for strength.


Here each of the discs has been glued and bolted in places that won’t interfere with the rungs that are still to be added.  The discs also have yet to be rounded.