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Mill repairs 2015 day 7

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29th August 2015. Mostert's Mill Ready for Action again!

Article reproduced with kind permission of Andy Selfe 
Original can be found here http://compagnesdriftmill.blogspot.com/

 

Some correspondence from past Chairman Brad Wallace-Bradley led to some concern about a photo I had shown in the previous report of the lower end of the stone spindle, where it runs on the dome washer. This small area supports the full weight of the stone spindle, runner stone, upright shaft and lantern pinion. The photo showed a piece broken away from the periphery which was not recorded the last time the spindle was dismantled for inspection.

'Bol end' of the stone spindle showing longitudinal cracking in the wrought iron and chipping



So the first thing we did today was to withdraw the spindle again for closer inspection. The texture of the metal shows longitudinal cracks in the iron which is clearly wrought, and some splaying out at the end. There were two possible courses of action, one to reassemble it like that, the other to trim off a little all around. We chose the second option.

Chamfer ground away on the outer edge



After rubbing away the rough edges with emery paper and cleaning it thoroughly, we refitted the stone spindle and got busy with the business of the day, to turn the runner stone over and balance it. We started by moving the runner closer to the centre of the bedstone, supported on the trolley-jack near the wall and a round rod on the work-table. At all times we had spacers and the many-heights between the stone and the work-table, as well as a plank between the runner and the bedstone.

Runner stone rolled back over the bedstone as far as necessary



When we were close enough to the centre of the bedstone, we started lifting with three of us making sure the runner didn't swing away left or right, also that it didn't slip inwards and hit the cock-head of the stone spindle! We had the runner standing on its edge on a plank, then gave it a nudge to balance over and after a moment of apprehension, started lowering it on to blocks and many-heights.

 

 

Lowering the runner. We didn't lower the stone on to the lighter bar fulcrum seen on the bedstone, I was standing on it to reach the chain block!




Now we got to the stage we'd been waiting for! Checking the static balance of the runner! We lifted the runner on a cable through an eye-bolt in the centre of the dummy cock-head I made.

Hanging the runner on the cable on the dummy cock-head



I had brought what I thought were enough weights, a bit more than 7kg. It was immediately clear that this was far from enough!

Alan playing Chess with the weights!



Alan had to go home and bring more lead weights, in the end we had something like 20kg arranged in an arc at the edge.

About 20kg of weights brought the runner into balance



We all agreed this would look ridiculous, so we discussed the options. One was somehow moulding the lead on to a band of hoop-iron around the circumference, which would have been out of sight, but we just couldn't work out how to actually do that. So we melted all the lead we had laid out into four ingots cast in a tapered Christmas pudding tin we found.



Neville's blow-lamp wasn't enough, Alan first went to fetch his, then again his gas hotplate. The three sources of heat were enough to melt the lead.

All that lead consolidated into four weights



We decided to attach them with Epidermix epoxy glue, which we had to go and buy. That was useful because there was another thing to glue, the Provincial Heritage Site tile which takes the place of the old (and to scrap-metal thieves attractive) National Monument badge. Steve had arranged this recently through the very helpful people at the SA Heritage Resource Agency.

The Provincial Heritage Site tile is not attractive to scrap metal thieves like the old bronze National Monument crest was

We mixed plenty of glue and applied it to the wide side of each weight after once again shifting them around to achieve balance.

A generous amount of Epidermix applied to one of the newly cast weights



We could then remove the dummy cock-head and assemble the 16mm rods of the chain-sling, as before using cloths and sacks to protect the upper edges of the runner from damage from the four chains. We vacuumed once again before lowering the runner over the stone spindle until the rods were just not pinched between the runner and the bedstone.

The runner is hanging on the cradle and John is giving it one last vacuum before we lowered the runner into position


We then assembled the tentering levers and raised the stone spindle fully into engagement with the rynd and removed the bars and chains. With the stones lowered together, we could then sling the upright shaft and raise it, swing it over and with three people upstairs guiding and two below, managed to engage the fork over the rynd the same way around as we marked it when we dismantled. We could hold the upright shaft almost vertical as we lowered, avoiding any possibility of damaging the fork or the rynd.

Upright shaft slung, ready to lift and lower on to the rynd



We then assembled the pintle bearing, remembering to add the 5mm spacer between it and the sprattle beam, to correct the out-of-line which we had picked up with the plumb-bob last time. There is still more than enough engagement between the brake wheel cogs and the lantern pinion.

Engagement of the lantern and cogs


There is an added advantage, there is just that 5mm more clearance between the upper band of the lantern pinion and the clasp arms of the brake wheel.

Additional clearance between the upper band on the lantern and the clasp arms of the brake wheel

 

Meanwhile the others were assembling the furniture.

Furniture assembled



I sneaked one last look at the four weights!

A peek at the weights, we couldn't test it until the glue had dried

So we are ready to test for the reopening of the Mill on 19th September. We have decided to dismantle the furniture on that occasion and watch the interaction between the stones, probably lying on the floor in a circle, like some pagan ceremony? :-)

Andy Selfe
29th August 2015

 

 

Mill repairs 2015 day 6

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1st August 2015. Mostert's Mill. Sickles into Harps.

Article reproduced with kind permission of Andy Selfe 
Original can be found here http://compagnesdriftmill.blogspot.com/

 

We all know the Biblical expression 'Swords into Ploughshares'; today we ground Sickles into Harps! But we did plenty more besides.

Last time we were trying to raise the part of the Bedstone nearest Cape Town with various levers, but the curb was holding it back. Today I brought a 'koevoet' made by a Railwayman and a few steel plates to lever the bedstone upwards. It still was being stubborn until, while I levered the stone upwards, Paul gave the curb a good smack downwards with a 4lb hammer, with a wooden block in between, of course.

Hammering the Curb down while levering the bedstone up

This had the desired effect! We repeated the procedure three times, every time gaining a couple of millimetres. Referring as before to the drawing on page 87 of Professor Friedrich Kick's 1888 'Flour Manufacture', I drew two overlapping triangles ABC and DEF and took readings with the spirit level on top of my Staff between each as he explains.

Overlapping equilateral triangles marked on the bedstone and Kick's book

When we had reached the stage where there was one or at a stretch two millimetres difference in total we decided we wouldn't get any better. By that time there was space to tap in a wooden spacer of approximately 7mm at the place we had raised it the most.

7mm spacer under the bedstone

Thinner spacers were inserted between the stone and the blocks on each side. We tapped down the wedges around the bedsone, flush with the curb again and Paul refitted the wedges we'd removed last time holding the curb in place.

Paul refitting the washers and wedges holding the curb in place

Here are our readings:

Readings taken when levelling

For a long time there has been concern about the state of the oil, flour and dirt mix in the footstep bearing of the stone spindle. This was an ideal opportunity to pull out the stone spindle and lift out the thrust bearing with a magnet that Neville had brought and to clean everything.

Neville dismantling the footstep bearing

Neville had been unaware of the loose washer under it which also came out with the magnet.

Bol spindle bearing and spacer with Neville's drawing

The relatively small thrust surface supports the full weight of the stone spindle, runner stone, upright shaft and Lantern Pinion.

This small area supports a lot of weight, and centralises the stone spindle in the bridge tree

We were then ready to grind out the sloping edges of the Harps I marked out last time. Using a piece of wood held in place by my left hand and either Neville or Paul's foot at the other, holding the angle grinder with a diamond-impregnated face-grinding disc at about the angle shown by Kick on page 94, I ground out to the 9 to 13mm deep that he suggests.

Grinding out the sloping edges of the furrows

It was difficult to judge the depth sometimes because the remaining surface was either grinding face or furrow from the old sickles. We were always comparing with the existing pattern on the runner.

How the Journeyman meets the Master furrow on the runner

.... and making sure the bedstone was the same, for example at the inner tip of the Journeyman furrow:

..... likewise on the bedstone

I did each pair of Master furrows first, all the way around, then filled in each harp in turn.

First Harp complete

In the end, we had a pair of stones looking very similar:

All Harps done!

The stone itself is very different from the runner, being volcanic.

Detail of the bedstone's texture

Paul vacuumed the bedstone thoroughly. John and Fortune will come back and give the whole Mill a proper clean now that we've finished making a mess!

Paul vacuuming the bedstone

With both the upright shaft and the stone spindle out, it was an ideal opportunity to check the vertical alignment of the pintle bearing in the Sprattle Beam, the neck bearing in the bedstone and the footstep bearing. Paul had his plumb-bob.

Paul hanging the plumb-line through the pintle bearing to check alignment with the bedstone and footstep bearing

We found the line going through the neck-bearing about 10mm too close to the University.

About 10mm too close to the University

Likewise (looking from the other side) at the footstep bearing.

Likewise at the footstep

We then checked between the neck bearing in the bedstone and the footstep bearing and found them vertically in line.

Plumb-line held central in the neck bearing, aligned nicely with the footstep bearing

The conclusion is that a thicker shim is needed between the Sprattle beam and the Pintle bearing blocks. Now the Brake wheel and Lantern are meshing properly, this will be a good idea. It will mean the top disc of the Lantern will be slightly further from the face of the brake wheel which had to be ground away for clearance.

We could then lubricate the neck bearing in the bedstone and the corresponding surface on the stone spindle with lard, pour gear oil into the footstep bearing cavity and refit the stone spindle.

I did some grinding on the dummy cock-head for hanging the runner stone from to check the static balance, after we have turned the stone over. It was made according to Neville's drawing of the cock-head of the stone spindle and it needed very little removed to fit snugly!

Dummy cock-head in the inverted Rynd

Last week I was pleased to meet up with Gawie & Gwen Fagan. Gwen was responsible for laying out the Gardens, Gawie for ordering the removal of the unnecessary concrete lining to the Mill tower (and much more!) during the 1994 restoration. He asked whether we were being paid for our 'work'. I said no, we were happy to do this for nothing but if he had any influence at Public Works, we would appreciate him asking for a re-paint. A stitch in time saves nine!

Paint beginning to crack

Faded paint on the door

Paint cracking up on the Wind boards and varnish at the top.

We all packed up, well pleased with the part-day's progress, at around 3.30. Next steps are to turn the runner over again, hang it and balance it statically, to refit it to the stone spindle and to assemble the furniture and start Milling!

Can we go home now?

So There! 

:-) Andy

1st August 2015

Link to Day 7

 

Mill repairs 2015 day 5

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4th July 2015. Mostert's Mill Tackling the Stones

Article reproduced with kind permission of Andy Selfe 
Original can be found here http://compagnesdriftmill.blogspot.com/

 

The brake wheel and lantern pinion mesh well now, so after one or two Milling Days to keep up interest from the Public and to generate some funds, we knew that the second part of the job was in store still, the dressing of the stones. There was no wind forecast for today so it seemed an ideal opportunity to tackle the job!

Road sign next to Mostert's Mill

Our tool list included my 'staff' which I had to 'prove' on the big Mitchell lathe bed first. I haven't used it for a long time and I wasn't at all surprised to find it had developed a bow. It touched at both ends and there was perhaps a millimetre gap in the middle. After some belt sanding, then hand sanding the high spots off, I had decent contact area between the chalked lathe bed and the staff.

Proving my staff on the flat bed of the lathe

Neville had opened up and was waiting for me. He with a car full of tools to go along with mine and Paul's; we were well equipped, but one never has everything! We soon had the furniture stripped off the stones, although to remove the long beams of the horse, the corners of the upright shaft need to be turned out of the way, so the brake had to come off and the diagonal 'preventers' removed from between the brake-wheel rim and the sprattle beam. We had to turn the wind shaft anyway, so that one of the flat surfaces faced down, to give maximum clearance to lift the upright shaft out of the eye of the runner stone. We also lifted the two halves of the floor and tied them safely to prevent them falling closed when least expected!

For lifting, we had a chain block hanging from a strop on the wind shaft, first on the brake wheel side of the tie-bars, then we realised we wouldn't be able to pull the shaft away from the sprattle beam like that, so we hung it on the other side.

Strop hung on the brake wheel side of the tie bolts

Looking down, the strop is now on the other side of the tie bolts, the chain block on it is connected to the other strop around the upright shaft. Neville is loosening the bolts on the pintle bearing

Then the other strop was wound twice around the upright shaft, with a safety rope down to the quant at the bottom, in case it slipped upwards. Neville is removing the nuts and wedges on the pintle bearing housing in the picture above. The strop is now on the other side of the tie bolts. With the chain block in this position, the fork on the quant lifted cleanly off the rynd without any tilting action, which has been a concern before. There is still not enough clearance when the pintle up against the wind shaft, but by swinging the lantern pinion to the left (opposite side to the brake lever), it was easy to lift further, making sure the lantern did not hook up under the sprattle beam. The quant could then clear the eye of the runner. Once out, we had a wooden block on the floor ready for it to rest on, at the top of the stairs so that we could lower the fork of the quant on to it and tie the upright shaft safely into that corner of the opening.

I had brought the chain-and-rod cradle which we use to lift the runner at Compagnes Drift. It was just big enough for this stone. Here the 16mm rods are laid out on top of the runner:

Cradle laid out on top of the runner

It's only necessary to raise the runner with the tentering mechanism by a little more than 16mm to assemble the rods. Shackles on the ends of the four chains of the sling go over the ends of the two long rods, right against the edge of the stones, then the shackles welded to the ends of the shorter rods are slid over the ends. They just hold the long ones apart. We used rags under the chains where they passed over the top edge of the runner.

Chains connected to the ends of the rods

Lifting, with rags under the chains to prevent damage to the top edge of the runner

The next problem was to disengage the tapered cock-head of the stone spindle from the rynd. For this I had brought a heavy duty automotive puller. We cut two short lengths of ready-bolt and assembled the two halves of the bearing puller under the rynd and connected the legs of the threaded part to it. With a bit of adjustment we had a fair amount of force downwards on the stone spindle and upwards against the rynd. To prevent the stone spindle falling and damaging the hollow curved end where it runs on a cannon-ball, Paul raised the bridge tree to just touch. The stones were still just 16mm apart with the runner resting on the bars of the cradle. A couple of fairly strong belts on the top end of the puller with a 4-lb hammer while under tension, was enough to just dislodge the tapers, the stone spindle just dropping away a couple of millimetres.

Puller assembled under the rynd to force the stone spindle out of the taper

We could then lift the runner on its own. Working ever safely, as it lifted, blocks of wood and the 'many-heights' were used between the stones in case anything went wrong with our lifting apparatus. Our next plan was to hang the runner from a hollow dummy cock-head I had made, to check its static balance. I had used a 3mm wire rope through the hole in the middle with two Crosby Clamps inside the hollow end and with a loop at the top end with two more. Still with the blocks under the runner, we tried lifting it.

The wire rope snapped where it passed through the top plate of the dummy. Was it from the sharp edge of the hole underneath? Maybe. We changed the arrangement by drilling a bigger hole so the wire could pass twice through it and assembled with the wire around the bar of a D-shackle and out through the hole again with the Crosby Clamps above the dummy and tried again. The wire snapped again. Clearly not strong enough! We dispatched John to Hawkes and Findlay in Observatory where he found some 7mm wire and suitable clamps for that size. He also came back with a super book on Observatory and all its old buildings and Windmills!

However, we had moved on, by arrangement. We can do the balancing later. We turned the runner over using the strop through the eye of the runner passing one end through  the other to pull tight. We had the 'work table' in place. This is very sturdy and the same height as the top surface of the bed stone.

Lifting one side of the runner to tip it over

Using wooden blocks under the edge, we gradually lifted one side up, gave it a nudge at the balance point and lowered it on to the table. We used a towel on the chain as we lowered to keep the chain wawy from the beam on that side. Alan is making sure the runner didn't slip inwards with his foot. Later he used a wooden spacer there between the runner and the stone spindle.

Lowering the runner upside down on to the table

Fortune did a great job of cleaning the bed stone. It's well known that these stones were not a pair, the runner being dressed with harps and the bed with sickles. This is the first time I've seen sickle dressing in the flesh and I wasn't surprised to find every second sickle only reaches half-way.

Sickle dressing, up close

Our next job was to check if the bed stone was level. As expected, it isn't. There is about 3 to 5mm to lift on one side.

Checking for level, with the spirit level on the staff

We thought of several methods of lifting it, but we didn't have the right tools. The bed stone is firmly wedged into a solid heavy curb which will probably have to be lifted along with the stone and either left like that or 'encouraged' to go back down into its place on the floor once the stone is level. The curb is fixed down with bolts which pass right through the hurstings, not with nuts on the end, but wedges. The wedges have a tail on the wide end through which a nail was driven upwards into the hurst frame. Luckily these broke away easily and it was possible to drive the wedges out and save the washers. These are now attached with fine wire to the slots to make sure they don't get lost or mixed up!

Curb retaining bolt wedges and washers are tied in place

So the next job was to take a tracing of the harps, off the upturned runner. We did this first with brown paper, then transferred it to a piece of hardboard which I got on Friday from Simon of Overberg Joinery Works, who replaced the rotten longbrace beam some time ago.

Simon repairing the longbrace a few years ago

Tracing the harps off the runner

I then laid the paper over the hardboard and used a knife to transfer the pattern.

Transferring the tracing to the hardboard

I then used a handy electric tool called a Renovator to cut through the board to work as a stencil.

Stencil over the bed stone, registered on the stone spindle

We measured the diameter, calculated the circumference, divided that by eight for the harps and made eight equally-spaced marks on the iron band around the bed stone. By this time we were pretty tired and had difficulty working out which way the harps should face to match those of the runner, so that the crossing angle would encourage the partly milled grain outwards. I had brought along (to show it off!) Nigel Harris' new book, Watermills and Stoneground Flour Milling. He came to the rescue on page 118, with pictures of a pair of stones from Letheringsett. The runner in that case turns in the opposite direction to 'ours', but it can be clearly seen that when the runner is upturned, the pattern of the harps on one is in the same direction as the other. So the stencil is used the same way up on each!

Even though much must still be done to the upper surface of the bed stone to get it level and flat, we decided to mark out the harps using a thin diamond impregnated disc. We marked a ring at a suitable radius on the disc so as not to cut too deep nor be too shallow and off we went, each time using our marks on the iron band against the stencil to make sure we were exactly one eighth of a circle away from the last.

Using the stencil to cut grooves in the bed stone to a certain depth

The result was very pleasing!

Harps marked out on the bed stone

We have arranged to meet again in four weeks for another work party. For that, we will bring suitable apparatus to raise the bed stone. We will use offcut hardboard as shims. I will reassemble the dummy cock-head with the thicker wire rope.

:-) A

Link to Day 6

 

Mill repairs 2015 day 4

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9th May 15. Testing Mostert's Mill under Wind Power

Article reproduced with kind permission of Andy Selfe 
Original can be found here http://compagnesdriftmill.blogspot.com/

 

Last time, we tested our work after assembling the pintle bearing at the top and centralising the Lantern pinion, by turning the sails by hand.

Turning the sails by hand last time to check meshing

Today, expecting a reasonable wind, the word had gone out by Fine Music Radio that we would be 'Open for Milling'. I had other things to do on the way so by the time I arrived, all was set up with sails bent and reefed according to the expected wind.

I had indicated that I wanted to inspect the stones running close together with the tun off, either at the beginning or the end of the day. We decided to do it as I arrived. The furniture was quickly dismantled.

Removing the tun to inspect the stones from the side

The out-of-true between the stones is not as bad as I thought, however what was noticeable was that the top of the runner is very irregular. We held a fixed pointer just above it and the difference between the highest and the lowest spot was about 20mm. This is likely to cause a serious out of balance while running, and could cause the runner stone to lean one way while at operating speed.

We did another test; Neville attached little cones of Presstick to the upper ring of the lantern pinion and we turned the windshaft more than 16 turns. It is only after 16 turns that the same cog engages with the same rung again. With wind on the sails we were assured that the rear of the windshaft was fully against the thrust bearing, and the clearance between the brake wheel and the lantern at its least. Several of the cones were pressed surprisingly flat. What we were specifically concerned about was that the upper ring is very close to fouling the outer rim of the brake wheel. If we have any cause to work on the lantern in the near future, especially after having dressed the stones, we will raise the lantern away from the two supporting lugs on the upright shaft, but not too much, otherwise the upper edge will foul the steps in the clasp arms.

Brake wheel (left) and lantern pinion

When we open the stones to dress them, we plan to do a static balance test on the runner. My plan is to hang the runner on a cable using a copy of the tapered cock-head of the stone spindle. When the runner was last off, Neville took down the dimensions of the taper. His drawing can be seen on the right in the picture below. His calculations for the weight of the runner can be seen too!

Neville's sketch of the cock-head of the stone spindle and the rynd

I set about making a copy of the taper, using 6mm thick steel plates, cut to size, and welded them together. In the very centre of the small end, I drilled a hole so we can hang the runner stone on it and add weights to the light side until it balances.

Fabricated copy of cock-head taper

With the furniture all reassembled, milling began under wind power and a stream of interested visitors could be shown around. The wind wasn't steady so it taxed Adam's skill at the controls at the meal spout!

As I'm completely satisfied that the meshing problem is now cured, the next two Open Days, set for Saturdays at the beginning of June and July, weather permitting, will be set aside for Milling. Thereafter, in winter, we'll tackle the dressing of the stones which should improve the quality of the meal.

:-) A

Link to Day 5

 

Mill repairs 2015 day 3

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11th April 2015. Mostert's Mill again, assembled!

Article reproduced with kind permission of Andy Selfe 
Original can be found here http://compagnesdriftmill.blogspot.com/

 

After leaving Mostert's Mill last visit, I realised that it would be good to have the Pintle Bearing bored true, now that the pintle itself is set firm and vertical in the Vertical Shaft. I asked Neville to collect the two halves from the mill, he gave them to Pieter, who brought them all the way to Compagnes Drift Mill in Bot River two weeks ago, and I dropped them off at Orbit Engineering with specific instructions as follows:

1 Mark 1 and 2 permanently in blocks (we had marked them with chalk. There are two X's to show how they go together, but the 1 and 2 show the top and which way around we removed them).

2 Measure the full length of the two blocks together.

3 (Having established that they had 3mm steel plate) Machine off 3mm from each side of both of the mating faces of the bearing halves.

4 Make and attach 2 steel shims 3mm thick to the mating faces of one of the blocks.

5 Clamp the two together, align, and bore to 43mm. (It would not matter if this didn't remove all the hour-glass wear. In fact it did).

6 Make a 3mm shim the full size of the end of the block.

7 Check the assembled length, it must be the same as 2 above.

The same team assembled today, 11th April, thanks to all of you before I forget! We decided to use the opportunity, while the Vertical  Shaft was not engaged on the Rynd to observe how the Runner Stone turns while the stones are separated. We know there are problems with the Bedstone which is not flat, but it would be good to know if there was any wobble on the Runner, at least at slow speed, especially as the Rynd is tight in the Runner and tight on the tapered Cock-Head of the Stone Spindle.

The Vertical Shaft was resting on a block of wood on the Stones, so we rigged the chain block from a strap over the Wind Shaft, lifted the shaft clear and carefully lowered it on to wooden blocks to one side of the Stones. Here Paul is attaching a safety-rope to ensure that the strap couldn't slip upwards on the shaft, which tapers slightly towards the top:

Paul tying a safety rope on the straps on the Vertical Shaft

The results, using nothing more scientific than my finger as a 'feeler' were very satisfying. However, with the runner well clear of the Bedstone, it's very clear there are problems with the latter! Here one can see that the Runner is rubbing on the Bedstone (which, technically, it shouldn't even touch):

Signs of the Runner rubbing on the Bedstone

.... while in this area there is partly milled meal from last Milling Day:

In this section there is a gap where the meal is only partly milled

We also decided that, because we will have to remove a considerable amount of material to get the Bedstone flat, we will dress it with Harps like the Runner. The stones are not a pair, the Runner has Harps, the Bedstone is Sickle-dressed. No doubt we would have experienced resistance to this decision from the traditionalists, but to sacrifice proper Milling to sentiment is not an issue.

This is how the Bedstone is set up, according to Professor Kick (in 1888):

Professor Kick's advice on levelling a Bedstone, in 1888!

All this was in preparation for some day in the future when we tackle the Dressing. Today we had decided to reassemble the top of the Vertical Shaft and the Lantern Pinion, so that we can test the Milling with all the problems at the top corrected. This is how we left it last time, with duct tape to hold any Steenvas from oozing out of the sides:

The top end of the Vertical Shaft with duct tape to hold the Steenvas in place

With the tape pulled off, it left a smooth finish on the Steenvas:

Duct tape removed, leaving a smooth surface on the Steenvas, now very hard

This picture makes me realise that we didn't nip-up the nuts on all the through-bolts. This will have to be done before the next Milling Day, to give the Steenvas the best opportunity to work. But first, we had to re-step the Vertical Shaft on the Rynd. There was some discussion as to whether or not to build up wear we could see has occurred on the fork (or in fact to grind it flat as worn), and which way around it should go. There are (fading) blobs of paint on each, which is how it has been assembled all along, but we found an X on one side of the fork and another X on the Rynd, which would mean we were 180° out. Then someone found another X on the other side of the Rynd! In the end we decided to stick with the paint marks.

I lifted with the chain block while Morne took charge of the top end........

Morne guiding the top end of the Vertical Shaft

..... and the others guided the bottom into place:

Neville, Pieter and Paul guiding the fork back on to the Rynd

We then slid the Lantern Pinion loosely over the top of the Vertical Shaft until it rested on the two brackets, as we wouldn't have an opportunity later, and clamped the two halves of the reconditioned Pintle Bearing together and tested it on the Pintle. We all decided that the fit was slightly too tight. Pieter's own Mill caught fire from heat generated from a Pintle Bearing with too little play. We discussed methods of shimming the mating faces a bit, including cutting strips off one of the existing shims from the ends, which are interesting in themselves:

Interesting shims cut from an old oil tin

Remember the Standard Vacuum Oil Company or 'Stanvac' which became Mobil in 1962? Well the Standard Oil Company of New York (Socony) merged with the Vacuum Oil Company in 1931 to form Socony-Vacuum, so this tin must be older than that! Could they have been cut by Mr Bremer snr during the 1935 restoration?

In the end we decided that cardboard would work adequately, so cut two shims and tried assembling like that. Of course, with the two halves in the recess in the Sprattle Beam, there wasn't enough clamping force to hold the cardboard shims in place anyway. They fell out, so we left them out and tested the assembly with one thin shim at the end omitted. We were all very happy with the (little) play.

Pintle in the two halves of the bearing in the recess of the Sprattle Beam

When we stripped, all the shims were on the right hand side. Today we decided to fit the new 3mm shim on the left and the remainder on the right. It doesn't matter that the mating faces of the bearing halves aren't tight against one another. Besides the pair are tightly clamped from the side by the bearing cap which also has a corresponding recess in it. Here the cap is fitted loosely over the bearing..... (those are not our hammer marks!)

Bearing cap loosely over bearing halves

....... and here, the tie-bolts are pulled through, new washers, 5 on each side, with the wedges nicely half-way down.

New washers, five a side, and wedges half-way in

Shipshape? But I forgot to mention lubrication: we had applied a liberal application of lard when we assembled the bearing. The two 3mm shims on the mating faces can be seen in this picture, held in place by wood-screws, as well as the cleanly bored hole. In future, as the hole wears, thinner shims can be fitted to the faces and corresponding shims fitted at the ends to apply more clamping force:

Lard applied to the Pintle for lubrication

I had hoped we could turn the Vertical Shaft on its own at this stage with the Lantern Pinion still loose, but there wasn't enough clearance even with the wedges out, so we set about refitting the wedges and setting the Lantern to run true. We found that we had done ourselves an enormous favour by marking the Lantern according to the Vertical Shaft, as well as every wedge, as we removed them. Further, by refitting them to more or less to where the marks showed they had worked before, the Lantern was nearly running true before we started checking! Here, Morne is refitting the wedges and the marks on the wedges can be seen:

Morne refitting wedges to the Lantern

I then set up a register, clamped to the Sprattle Beam, set vertical with Neville's spirit level. From this I could measure to the top and bottom bands of the Lantern, singing out the readings to Secretary Steve with the clip-board.

Measuring from the vertical register clamped to the Sprattle Beam to the top and bottom rings on the Lantern Pinion

It only needed fine-tuning the last few millimetres and for Pieter to tap in the wedges to an even tension. We discussed whether the Keepers should be replaced at this stage, to hold the wedges from slipping out. I was for trying it out for a while without, but was easily persuaded that it would be better to refit them, even temporarily with nails protruding for easy extraction. The consequences of a wedge or a pair of wedges falling out would not bear consideration! The top set do not need them as they work themselves in by their own weight, besides there's the steel band on the top of the Vertical  Shaft so there's no way they could be nailed in. We also refitted the Keepers in the Wind Shaft. Here Neville is cutting new Keepers:

Neville cutting wooden strips for Keepers

We were then ready to test the meshing. In fact we had planned to Mill, but there wasn't even the 2 m/sec that Yr.No had predicted, so John and Paul turned the sails by hand while we watched the meshing carefully.

John turning the sails by muscle power

Here is a short clip showing the meshing: https://www.youtube.com/watch?v=XiDvNi0OQcw. As I say on the video, I'm very happy with the results! Morne did another from the side: http://youtu.be/nu3YiAfJPAU

We plan to Mill in four weeks time and to observe very carefully the interaction between Runner and Bedstone and the fork on the Rynd. At some time in the future, we will open up the Stones and sort them out for good!

:-) A

 

Link to Day 4

 

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