Tuesday, 13 March 2012
Problem with axletree bearing
Since we started running the mill this season, there has been a loud clicking, creaking or clunking noise from the main gears. It seemed to occur about once for every turn of the spur wheel.
Today Richard decided to firm up the wedges holding the pit wheel on the axletree (main shaft or wheelshaft). However, while he and Ray were doing so, they realised that the noise was actually coming from the end of the main shaft. It seemed that the wood had shrunk away from the cross-shaped metal frame (which might be called a gudgeon, the glossary I have is not quite clear on the subject) which holds the bearing pintle. The "fins" of the gudgeon were therefore able to move in the wood, each revolution making it move once up and then once back the other way - twice per revolution of the pitwheel being once per revolution of the spur wheel.
We hammered some iron and wooden wedges into the spaces, ran the wheel, and found the noise had gone. We will have to keep an eye on the end of the shaft in future.
Meanwhile Bob and George were clearing more of the overgrowth from the cobbles between the mill and the spillway, until George's pressure washer motor burned out. Many of the stones edging the launder platform and the spillway pit are loose and will have to be re-bedded.
There is some evidence that they were originally bedded in sand and cement mortar, rather than the lime mortar we would tend to use in most places.