Tuesday 10 August 2010

Preparing to restore the French Burr stones

The second pair of stones in the mill are French Burrs, which were used to mill wheat flour. Like the first pair, these stones have not operated since WWII.

Naturally, we would like to restore these stones to working order with the intention of milling some flour in due course.

There are several problems - we have no idea what state the stone faces or bearings are in, the support beam is twisted, the stone nut is mounted too high on the shaft to mesh with the spur wheel, and it is also too close to the spur wheel so the gears cannot engage. Apart from that and the fact they are enormously heavy (over a ton each), it looks quite simple. Oh, and there is no beam in the roof in a suitable position to attach a lifting block.

So, the first step is to fit a lifting beam. After lots of calculations to work out how big a beam we needed to span the 3m gap between roof timbers above stones 2 and 3, we eventually ordered a length of oak, 3.5m long and 20cm square. On August 10th this 150kg monster was dragged across the yard on rollers and then pulled in through the half-door by a hoist attached to existing timbers. By using hoists in various positions, and extra manpower provided by Chris Braithwaite, we eventually got it lifted into place.

The lifting beam in position with 3 ton chain block

07/09/2010 We fitted blocks to the ends of the beam to stop it slipping out. During the hammering a bat fell out of the roof. Following instructions, we picked it up (wearing gloves) and stuck it on the wall, from where it flew back to safety.