Author Topic: water Mill restoration  (Read 3437 times)

Offline smiffy

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water Mill restoration
« on: November 03, 2018, 06:08:46 PM »
For nearly a year I have been restoring  a 1790 water mill that belongs to a friend . This is a 2 stone mill  driven by a undershot wheel .
There is also a turbine which I have reinstated
All the work is being done single handed so progress is fairly slow and as this is a private project funds are limited.
The pictures here are of the francis turbine which has a 24 inch runner and works at a head of 5 feet .
All the bearings are lignum vitea and I have used all the original ones as new lignum vitea is almost unobtainable 
 My objective is to be able to produce flour some time next year

Offline charadam

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Re: water Mill restoration
« Reply #1 on: November 03, 2018, 06:56:57 PM »
Where are you in the world?

A location might well produce volunteers, cash, or lignum vitae bowls (bowling green type) that might do for replacement bearings.

I would volunteer if you are not too far away from Wem, Shropshire.

Offline WeldingRod

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Re: water Mill restoration
« Reply #2 on: November 04, 2018, 03:51:58 PM »
There's a gent supplying lignum vitae bearings for engineering applications, and growing the next generation...  ran across it in the ASME magazine a few years ago.

Sent from my SAMSUNG-SM-G891A using Tapatalk


Offline smiffy

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Re: water Mill restoration
« Reply #3 on: November 12, 2018, 02:51:12 PM »
A few more pictures of the francis turbine . The first thing was to split the drive shaft and remove the coupling then remove the thrust pad and thrust bearing that is a block of lignum vitae 
Then I removed the spider which controls the opening of the vanes . This took some considerable time as everything was seized solid .
Then it was possible to remove the top plate and expose the vanes and central runner .
The years of water running  through it had formed very hard limestone scale that made dismantling very difficult .
  Thanks for the idea of using bowling balls but unfortunately they are way too small as the main thrust bearing would require a cubic foot which would be available but  at great cost

Offline AdeV

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Re: water Mill restoration
« Reply #4 on: November 12, 2018, 04:52:08 PM »
That's some proper old school engineering there! What are the cups made of in the turbine, they look like cast iron - if so, that would be absolute cutting edge technology for 1790?
Cheers!
Ade.
--
Location: Wallasey, Merseyside. A long way from anywhere.
Or: Zhengzhou, China. An even longer way from anywhere...
Skype: adev73

Offline smiffy

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Re: water Mill restoration
« Reply #5 on: November 12, 2018, 05:33:09 PM »
The turbine was installed in 1907 to to power a generator to provide electricity to a local house for a set number of hours each week . There were also 2 electric bread ovens installed in the mill  . Unfortunately both generator and ovens are long gone .
Before the turbine was installed there had been a small undershot wheel driving one set of stones .
 At the other end of the mill is the larger wheel driving 2 sets of stones .

The turbine runner  is the most  fantastic casting , all the other runners I have seen have pressed steel buckets but this is all one casting.

 The other pictures show the bearing housing which sits on top of the spider frame . The whole weight of the shaft and runner is carried on the wooden thrust bearing  This housing also houses 3 radial bearings  The reason why the turbine stopped working is probably because this housing was broken .
 I repaired it with strong backs to secure the 3 radial  bearing   
The original bearing retaining plates had been held in by 4  3/8  bolts on each of the bearings . these had all sheared and the whole assembly tied together with a thin steel strap

The other photo is of the operating gear . This turns the spider to open or shut the input vanes  The original was missing so I cut the ew gear out of 15 mm plate a welded 3 pieces together

Offline charadam

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Re: water Mill restoration
« Reply #6 on: November 12, 2018, 07:44:34 PM »
Smiffy,

Maybe the bearings could be made in this fashion, rather than a solid sizeable lump of LV?

https://lignumvitaesolutions.com/products/marine/stern-tube-bearings/

Offline vintageandclassicrepairs

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Re: water Mill restoration
« Reply #7 on: November 13, 2018, 03:13:08 PM »
Hi Smiffy,
I'm really enjoying seeing the progress on the mill  :clap:

From what I can see in the photo of the turbine wheel, the end of the shaft (bottom end?)
looks to be worn down to approx half its original size?
If there was that much play in the rotating shaft and wheel was there any contact wear between the turbine
blades and housing?
The inlet guide vane mechanism design is very similar in principal to the Gas turbines I worked on !!

John

Offline smiffy

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Re: water Mill restoration
« Reply #8 on: November 16, 2018, 05:19:01 PM »
The spigot on the end of the rotor shaft is not a bearing ,it locates in light cast iron cross piece in the output tube and once the main bearings are set it should not make contact with anything   . I have not got any pictures of the support cross piece as it was always under water 
At some time the bearings had got out of order and that is possible when the shaft became worn
As I have mentioned before the main shaft is supported on 1 main thrust bearing and 3 radial bears on the turbine .

The main shaft is  2 pieces of 3 inch sold bar joined in the middle . The top of the shaft is supported in a plain bronze pillow block bearing
The photos show the bearing housing and the retaining plate which had come adrift because the bolt had sheared.
 
I have also started to make a new gear to replace the cast bevel gear which is called a wallower 
To make the gear I am going to fabricate it and started by making the teeth by sawing at 30 degrees 5 inch lengths of 45 mm x 45 mm
solid bar  I did it in my old power hacksaw as it gave a better finish than my friends all singing and dancing cnc band saw
It took 10 hours to cut 44 teeth

Offline smiffy

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Re: water Mill restoration
« Reply #9 on: November 28, 2018, 03:14:26 PM »
Started  work on the new gear , the original is all 25mm thick cast iron . I could have made the new gear from steel of the same thickness but on refection that would be overkill and the cost of 25mm is a bit pricey ,plus bending it is more than I can handle .
 So I settled on making the whole thing  from 12 mm plate mainly because I had a 2 x 1 meter sheet to hand
 
Profiled out the main hex section on a cnc machine and folded a piece of 130 x 12 mm plate into a hex to make the center section tomorrow I shall weld it together
Then I will have to roll a cone at a 20 drg angle to weld the teeth to , That could be a bit of a problem as I have not formulated a plan of action yet
I might do it in 2 sections in my press

Offline smiffy

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Re: water Mill restoration
« Reply #10 on: November 28, 2018, 03:30:45 PM »
This is the gear that I am replacing .It is driven from the pit gear on the main wheel and drives the vertical wooden shaft .
This shaft has a large cast iron gear on it with wooden teeth that drive the mill stones
The gear is held onto the hexagonal  wooden shaft with wooden wedges

Online awemawson

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Re: water Mill restoration
« Reply #11 on: November 28, 2018, 03:32:54 PM »
Very nice bit of bending - and it fits  :thumbup:
Andrew Mawson
East Sussex

Offline smiffy

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Re: water Mill restoration
« Reply #12 on: November 28, 2018, 03:38:39 PM »
Thank you, not sure if it was luck or judgement ,possible a bit of both
Mike

Online awemawson

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Re: water Mill restoration
« Reply #13 on: November 28, 2018, 03:45:09 PM »
Years of experience I suspect  :clap:
Andrew Mawson
East Sussex

Offline Pete W.

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Re: water Mill restoration
« Reply #14 on: November 29, 2018, 05:05:02 AM »
I believe that those inserted wooden gear teeth were often/usually made of apple wood. 
Best regards,

Pete W.

If you can keep your head when all about you are losing theirs, you haven't seen the latest design change-note!

Offline smiffy

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Re: water Mill restoration
« Reply #15 on: November 29, 2018, 03:12:31 PM »
Traditionally the teeth are supposed to be made of apple or pear wood but in reality they were made out of what hardwood was available, Horn beam is a good alternative along with elm
Welded up the first part of the gear today , tomorrow will get it welded up and start making the cone .
Mike

 

Offline vintageandclassicrepairs

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Re: water Mill restoration
« Reply #16 on: November 29, 2018, 03:29:36 PM »
Hi Mike,
Great to see the work progressing :clap:
One small point though, I can see eight sides in what you described as a hexagon  :Doh:

 :scratch:
John

Offline smiffy

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Re: water Mill restoration
« Reply #17 on: November 29, 2018, 03:52:09 PM »
My mistake should have been octagon
Nice to know that someone is reading my ramblings and paying attention
Mike

Offline smiffy

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Re: water Mill restoration
« Reply #18 on: December 02, 2018, 12:35:44 PM »
Started making the outer cone for the bevel gear  Decided to use 8mm plate bending anything thicker becomes a bit of a issue.
Originally I was going to use plate of the same thickness of the casting . I decided that this was a bit overkill and went for the steel sizes that I had in stock and could easily handle . Making the cone in 4 pieces as I could cut the shape required from a piece of 180mm x 8 mm .
Cut pieces of plate to match the radius of the cone and formed them in the bender .

Clamped it up and with a bit of help from some clamps and the No 1 persuader a 28 lbs sledge hammer 2 of the sections are finished
Should be able to finish it tomorrow and start welding the teeth on

Mike

Offline hermetic

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Re: water Mill restoration
« Reply #19 on: December 02, 2018, 01:53:12 PM »
 Can you buy that tooth shaped steel, or are you milling it up? That is a superb bit of fabbing!

Offline vintageandclassicrepairs

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Re: water Mill restoration
« Reply #20 on: December 02, 2018, 02:45:32 PM »
Hi Mike,
It looks like you are well equipped to persuade steel into shape and keep it there with those serious looking clamps :clap: :clap:

John

Offline smiffy

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Re: water Mill restoration
« Reply #21 on: December 02, 2018, 02:56:02 PM »
The teeth are cut from 45 x 45 steel bar  . The angle is 30 degrees one side and 90 the other
This is a singe direction gear so only the 30 degree  needs any attention
As I described in post 8 I cut the gears in  a donkey saw

When this is all made and fitted against the pit gear i might have to shape the teeth with a angle grinder , it will depend on how the teeth have worn but it cant be any worse than the one that I am replacing as it was jumping out of mesh due to missing teeth
Photo is the pit gear I will take some better photos this week

Offline hermetic

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Re: water Mill restoration
« Reply #22 on: December 02, 2018, 03:02:53 PM »
Right, gotcha, are you getting two teeth out of one cut?

Offline smiffy

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Re: water Mill restoration
« Reply #23 on: December 02, 2018, 03:27:08 PM »
Yes 2 teeth per piece  but still had to cut over 2 meters of bar . Unfortunately the 45 sq was the only material I did not have and had to buy a 6 meter length . That was a big lump to handle
Apart from consumables ,mig gas and wire etc this is all I have had to buy .

By the time I have finished I will have used about 15 kgs of mig wire and 150 kgs of steel
 Only money spent 80 on the 45 sq bar  and about 30 hours workshop time  A bit different from the 3000 to 4000 quote for a new casting
 
 

Offline smiffy

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Re: water Mill restoration
« Reply #24 on: December 03, 2018, 04:26:40 PM »
Finished the last piece of the cone . The easiest way I find to measure a curved distance is to use a traveller . Blacksmiths and wheel wrights would use this tool to calculate the distance around a wheel and transfer the measurement to a tyre so it could be made to the correct size . I used it to measure the last piece of cone so that I cut the right length
A traveller is a disc with a center pivot held in a frame  , A chalk mark is made on the the wheel were it touches the object to be measured .Count the revolutions and mark the part revolution with a second chalk mark

Transfer this measurement to the piece of metal to be cut . I know most of you will know of this means of transferring measurements but it surprises me how many people do not . 
 
The other photo is just a small selection of G clamps . I dont use them very often now but when you need them they are invaluable .
I often wonder what will happen to all my tools when I no longer need them . The amount of younger people interested in getting involved in this type of work seems to be very small