SHED MATTERS 2

[Big Kev]

A good use of a bit of scrap on the cistern repair. The original plastic parts are built to a price, the cheapest usually.

[Stanley]

Thanks Kev..... I was pleased with it.
A message for my ladies.... I haven't been wasting my time. I have written 3 articles and delivered them, only 3 to go!

[Stanley]

I'm aiming for another three today. Good for my peace of mind, my back and my arm as well! Nothing is spoiling in the shed.....

[Stanley]

Sitrep.... I hit my target yesterday. Today is a broken day, Friday shopping and other tasks always interfere with shed activities. I have two more articles on the back burner and might finish them today. That will be me covered until the beginning of August and should cover the completion of the engines. So, bear with me ladies! I will take a view later on this morning.....
Later at 10:20. I wrote two more articles so no shed today. The good news is that I am now written up to August 12th and so the monkey is off my back..... Back in the groove tomorrow!

[Stanley]

I had a good clean up first. Today's job is to strip the valves out of both engines, mill the steam passage on the underside and grind the faces flat and frosted to get the best seal.



Both valves out, measuring done and we're ready to get going.



Both valves blued and marked. It doesn't matter if the sides overlap the ports a touch, there's plenty of room for the engine to breathe!



Set up under the mill. a 1/4" cutter and the belts altered to give me 1500rpm. Then it's just a matter of overcoming the fact I don't see straight and get them both chopped out!



Shortly afterwards, both valves milled out 3/32" deep. This doesn't sound much but it's plenty. Don't make the mistake of taking too much out.... This space is for the exhaust to get out and as it's exhausting to atmosphere there is almost no back pressure.



Newton's old slide valve lid brought out of the front room ready for grinding and frosting the valve face.



Then a bit of patience, about 15 minutes on each valve should do it.



That'll do it nicely. Make sure you get all the grinding paste off the valves....



Knocking off time. Both engines back in the shed ready for re-fitting the valves but that'll do tomorrow!

[micktoon]

Hi Stanley, they are really turning into things of beauty, works of art in their own rights , it's hard to see on the photos but are the milled out recesses just flat at the bottom or a stepped type surface, the photos make it looked stepped but I think they will be flat ? Cheers Mick

[Stanley]

Flat Mick, you are looking at the cutter marks. Worth repeating that 3/32" is plenty. I learned this under Newton's tutelage when I was fitting non-return valves in the clack box of the Pearn three throw pump at Bancroft. The usual lift allowed on them was over 1/8", often 1/4". Newton showed me that 1/16" was plenty and the valves worked better because they closed quicker. My way of explaining it is to saw into a copper water pipe and make a gap 3/4" X 1/16", even under that low pressure you'll be amazed how fast water gets out. The pressures in the cylinder of the engine are much higher and as it is exhausting to atmosphere will get rid of the steam perfectly well. Conversely, exhausting into a condensate main or similar will totally bugger the performance of the engine. Back pressure in the exhaust is a killer and leads to all sorts of problems. That was the trouble they had on the barring engine at Wigan Pier when John Ingoe asked me to go down and look at it but that's another story......

[Stanley]

Te first job this morning was to fit the freshly ground valves. No dramas beyond having to ease the 3/16" slot in Sarah's valve. I tried to be careful when I was milling the face but must have nipped it a bit, always a danger when you have chopped so much out of the blank.



Lots of small jobs this morning. The 3/4" cutter I have been using needed touching up.



Then the VM had to have the belts altered to get back to a more sedate 310rpm for the 3/4" cutter and that had to be mounted as well.



I found some 1/2" key steel for the clevis in the treasure chest and this meant I needed to put the four jaw on Mrs Harrison. Not often it comes out to play so a good clean out as I changed the jaws. I'm spinning it at top speed here to chuck the thin oil out before I use it. You can see the oil on the bed.





I'm making them as one until I split them after threading and cutting the slots, it gives me more to grab hold of under the mill.



Drill them both straight through 4mm which is tapping size for 2BA, the thread on the valve rod.



Close of play, ready for the milling the clevis jaws.....

[Stanley]

Today I want to finish the clevises and fit them. I've left them attached to each other so I have more to grip in the vise. A fairly sharp 3/16" cutter will do the job. Actually when I tried them against a standard they were a few thou undersized but that's not important, I'll make the ends of the eccentric rods to fit.



That didn't take long, nice clean cut....



I cut them in two and then individually faced the end clean, filed a chamfer on and then tapped them 2BA. The pic here is to show you an easy trick to make sure the clevis is central in the chuck. I'm using the side of the tool post to massage it straight.



After drilling a 3/16" hole for the clevis pin I gave them both a polish and broke the edges.



If I mount the eccentrics this way with the boss outwards I can get the eccentric rods a lot nearer in line. I'll have to reverse the eccentric straps to get the oil holes at the top but that's no problem. Tomorrow we can do some careful measuring.....

[Stanley]

The first job this morning was to reverse the brasses in the eccentrics so I could mount them with the boss outwards to reduce the offset to the valve rod with the oil hole on top. This got it down to 3/8" when I measured it.



Then the interesting bit. We want to measure the length of the eccentric rod which is the distance from the centre hole which engages with the clevis plus 1/4" and the face of the eccentric brass. So we need to set the piston and the valve in their correct positions. The piston at the back end of its stroke and the eccentric set so that it is just starting to open the back steam valve. We have quite a bit to play with because I have put plenty of thread on the valve rod for adjustment and the valve is mounted on the middle of the adjustment. I soon had the size and it's the same for both engines. I needed two pieces of stock about 7" long and 1 1/4" major diameter, that is the end from which the foot will be cut that attaches to the eccentric brass.



I had the four jaw on the lathe so I needed to swap to the 3 jaw SC. Notice that the nose is clean and oiled and I am using the board to protect the ways. You can let even a small chuck drop and dinge the bed!



Then I realised I was on the verge of a mistake. I needed the original Pratt 3 jaw on as it has enough clearance to allow a piece of 1 1/2" stock to go up into the mandrel.



I had a furtle in the treasure chest and came up with the ideal piece of scrap shaft. It just needs a light cut to bring it in at a shade over 1 1/4" diameter.



I honed my cutter, got the stock mounted and started cutting but soon realised that all was not well. At first I put this down to local work-hardening on the old shaft and changed over to a carbide tipped tool. I got going again and while it was far better, there was still something not quite right. I carried on with the cut down the length of the stock.



When I got to the end of the cut and wiped the bar down I found out why I wasn't doing well at all! This shaft must be about 150 years old! It's wrought iron. If you look very carefully you might be able to see the longitudinal striations in the surface which are the slag inclusions from the rolling process. It can be turned to a good finish but only with a tool set with a lot of rake. So what do I do? I decided that it wasn't good enough for what I want and tomorrow we will have another stock hunt! This is the penalty of using scrap, it's very satisfying but you never know quite what you are getting until you get the cutter into it. Never mind, I have a clean piece of WI which will no doubt come in for something......

[Stanley]

I was thinking about that piece of wrought iron. From the look of it I'd say it has spent many years as a piece of mill shafting and if so it would be a very early installation because mild steel made using the Bessemer Process was becoming economical and widely available after 1860. Probably started its life being driven by a beam engine....
Interesting to reflect that the piece of steel I was working with yesterday could well have been made by forging puddled iron under a water-powered hammer. The handrails of the Ellenroad engine are WI and made at a forge at Wortley in about 1890 so I'm sure that WI was used that late but not for shafts as the new mild steel was so much better. History in action!

[Super_7b]

Hi Stanley,

When you say Wortley, do you mean the one near Sheffield? I looked on the old ordnance survey map site and I see that there was "Wortley Iron Works" in an elbow of the River Don. The map sequence shows it active up to 1931 but disued by 1959. I see the modern maps list it as a museum. My eldest lad lives in Stocksbridge, but I never knew about this nearby museum. I must sort out a visit.

BR

Mick

[Stanley]

I did a search this morning and found this piece of inch and a half mild steel that was just long enough to make the two eccentric rods. Nearest I could get to inch and an eighth so nowt for it but some reduction!



This is a different kettle of fish. Nice short curly chips and free cutting. I hit one peculiar problem, for some reason, though nipped up as normal, the work was slipping into the chuck. I got another chuck key out with a longer handle and that cured it.



Once I had it to size it went for a chat with my friend Mrs Macmaster..... Then faced off at the sawn end.



Close of play. We are where we should have been yesterday, two blanks exactly the right length. I had a good clean up and all I have to do is change the chuck for the smaller more accurate Polish one and we are ready to make even more muck. As I always say, we spend all of our time making lumps of metal smaller.....
Mick, yes, that's the one. Well worth a visit.....

[Tizer]

Sorry to hear the local Co-op has stopped stocking your favourite St Bruno pipe tobacco. I hope you find somewhere else to buy it in Barlick before you get withdrawal symptoms!

[micktoon]

Hi Stanley, looks like that CI bar could have been a collectors piece amazing to think it's that old and been lying about for god knows how long. I know Blacksmiths have trouble getting cast iron now too. Shame about your favorite pipe baccy mind , have they stopped making it or just your shop not selling it now ?
Cheers Mick

[Stanley]

Wrought Iron Mick, not cast and yes it's an amazing survivor. Never found a piece of wrought shaft before... daft I know but I didn't mind wasting the time with it....
Tiz, shortage of Bruno is down to the Co-op. I haven't run short, I always have stock in. I ordered ten packs on the web last night but will still nag the Co-op.....

[Stanley]

I was a bit tardy getting into the shed, voting, shopping and cooking had to be done first. I changed the chuck, mounted the first blank and decided to take it down to 1/2" without any support from a centre. I can't put a centre in the end because it was only just long enough and I can't do any drilling at the clevis end. A very sharp cutter and a bit of care and despite the overhang, I managed.



Last cut on the first one.....



By knocking off time I had a good start on the second rod..... I promise I will do more tomorrow!

[micktoon]

Hi Stanley, I must have been tired the other night as I did mean to say wrought iron, hence the blacksmiths looking for it. I bet you wish those bars were a touch longer to centre drill them, things are still progressing nicely though. Glad to see the baccy situation is under control.
Cheers Mick

[Stanley]

I thought there must have been something.... You're right about the lack of centre and there were easier ways to do it. But I'm a stubborn old git and once I start I like to finish!

[Whyperion]

Wasn't rather a lot of wrought iron lost in WW2 scrap drives ?

[Stanley]

Don't confuse wrought iron with ornamental ironwork, much of which, particularly railings was cast iron.



I was tempted to have a different approach but carried on as before with no problems as long as I kept the cut modest.



Two blanks turned down to 1/2" minor diameter.



A good clean up, a new cutter sharpened and honed and set exactly to centre.



Knocking off time came. I am set up ready for finishing Both rods tomorrow.

[Stanley]

This morning hasn't been my finest hour. I woke this morning with the realisation I had cocked up with the eccentric rods. The clevis end should have been 3/4" diameter to give me enough meat to machine the offset into it I need to connect with the valve rod. For some reason, possibly distracted by the referendum (?) I never checked yesterday and turned the end down to 1/2". So this morning I had to have a rethink and accommodate the mistake.....



I put the shape into the eccentric end of each rod, turned the shaft down to 3/8" and left it at that until tomorrow when I will design a fixture that will thread onto the end of the rod and give me the offset I need. Bit pissed off actually with myself but I can retrieve the mistake.... I had a good clean up. Always a good thing to do when you have made a mistake.....

[Stanley]

I found a nice piece of steel 1" X 1/2", did a bit of measuring and started chopping bits out of it.



There are two offsets in here....



As you know, handball sawing is against my religion these days (I can't saw straight anyway because of my bad eye!) but I stretched a point and cut the surplus off, then I milled the cut straight.



Some more measuring, bluing and marking and then drill and tap 1/4" X 26TPI.



Split into two. They're beginning to look a bit more like now!



A bit of fitting and here is how the offsets mount on the clevis. They need finishing off now, new measurements taken and the eccentric rods cutting to the right length, turning down to 1/4" and threading so they can be attached to the rods.... They are going to be OK. In some ways I like them better than if they were cut out of the end of the rod....

[Stanley]

Forward with making the pins. First job was a clean up, then gather the tools together...



Resharpen my present favourite left hand cutter, hone it and set it on centre.



Next job, find a piece of 1/2" scrap and start making!



Best final check for size there is. A try out. Just right!



Both pins and collars made, now we have to drill them for the taper pins. Note the bush on the end to make sure I have the collar locked on the pin.



Final fitting and polishing done.



Now I can fit the clevis and offset and get a good measurement for the thread on the rod.



At knocking off time I had the first rod finished and ready for fitting. We know what we are doing tomorrow.....

[chinatyke]

Looking nice, Stanley. Wonderful stuff. I love the way you start with a chunk of metal and finish up with something very intricate.