Tuesday 27 March 2012

How heavy is the axletree exactly?

Aren't the daffodils lovely?

The main task today was to continue trying to sort out the loose bearing due to timber shrinkage on the end of the axletree. Martin Watts has recommended that we should use a number of very thin oak wedges. Richard reckoned that it would be easier to make sure the pintle stays centred if we either took the load off it, or drove in 9 or 10mm metal bars first and then wedged around them.

We therefore tried again to lift the indoor end of the axletree. This time we used 2 3-tonne chain blocks each with appropriate straps, each attached to a separate oak beam. Bob pulled on the two blocks simultaneously and monitored the tension in the chains, Richard watched the pintle and Ray watched the two beams. Eventually it was Ray who called that the narrower beam was bending. The pintle hadn't moved and the lifting chains were as stiff as steel bars. Given that we were lifting at one end of the axle, we should have been able to lift a distributed load of 12 tonnes, unless something was jammed. What is going on?
The heavy lifting arrangement

Elesewhere work on the grain store and the trash strainer continued. Ray fitted castors to the grain store frame, and Bob primed and painted the angle-iron corners, as well as the parts for the trash strainer.

The grain store makes more progress

Tuesday 20 March 2012

Grain store and trash strainer

Today saw several jobs being tackled.

Ray began building the grain store, as the wood and aluminium have now all been delivered. Here he can be seen constructing the solid wooden frame for the base - it needs to be capable of bearing up to 500kg of grain.

George continued pressure washing the cobbles, the ones nearer to the waterwheel being more difficult, as the plant roots are well established in the bedding layer. This is probably because they have not been cleaned for a long time..

Richard and Bob worked on mounting the stainless steel grid on a mild steel frame for the trash strainer, drilling and painting the steel bar sections that clamp it together. This will slot into the holder that was installed last week.

Later we all had another look at the end of the axletree. We are concerned that it would be risky to expose it to the strain of milling without making a proper repair. We are thinking of making a cylinder split into 4 segments all but at the end. This could be driven into the gaps around the cylindrical part of the gudgeon.

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.

Tuesday 6 March 2012

Trash strainer and cleaning

George cleans the steps
Our new man came today for his first day. George brought his own pressure washer, so after we had arranged a lot of hoses and mains connections he set about clearing the green slime from the cobbled path, fences and steps.
The cobbles see the light of day!

He then moved on to clearing all the vegetation off the launder piers so we can repoint them when launder rebuilding time comes. Between us we managed to get most of the green stuff off the cobbles under and beyond the launder, too.

The frame for the new trash strainer

Richard and Ray install the frame

Working in his home workshop, Richard has built the fixed frame in which the weir trash strainer will slide. The frame is welded from mild steel bar, and is to be bolted directly onto the inner surface of the take-off channel, and secured by flat bars bolted to the weir-side face of the stonework.

Last week he and Ray painted it, and today they fixed it to the weir stonework. The hope is that larger items will be carried over the weir by the water flowing across the strainer. The trash strainer measurements are to be taken once the frame is in place.

In the process, they found that the second weir is accessible at this time of year, due to the low vegetation, and also found an old mine truck abandoned in the river bank. It looks as though it had been filled with stones and used to reinforce the bank.

The old quarry wagon

The second weir