Shed Matters 3

[Stanley]

I carried on this morning where I left off yesterday. Dressing all the bearings so that all the external surfaces match up.



That's better, we're getting there but then I spent almost an hour with the files refining the finish. The old question always arises, how long spent on this stage is too long? 15 minutes on each is about right I think. We now have 4 bearings ready for boring and drilling for holding down bolts. They will look like castings when they are fitted and nothing wrong with that. That's what they looked like on the full size engines.



This was knocking off time.

[Stanley]

I'm thinking about boring the bearings so the first thing I did was mark both the bores and the holes for the holding down bolts.



First I started the bore on all the bearings by drilling out the start of the bore with a centre drill which is stiff and accurate. Then I bored all of them with a 7/16" drill.



But first I re-sharpened the drill and then ground the leading face of each wing so it was a negative rake. If you don't do this the drill will almost certainly grab especially with cast metal like this. Then I bored all the bearings.



This was knocking off time because I had to go to the Co-op to do my weekly shop when the least people are in there. All the bores have had their edges broken and they have all been checked with the 7/16" standard. They are all slightly oversize but that's OK I can manage that when I am fitting. Short morning but another step forwards.

[Stanley]

My first job was to mark for the holding down bolt holes.



Then under the pillar drill and drill all eight holes.



I matched the bearings up to the beam and then used that assembly to mark the top of the pillar before setting the column up under the VM chuck to drill for tapping for the trunnion bearings.



Then tap the holes while the column is held firmly on the bed of the VM.



That looks handy! We are ready for mounting the beam.



Of course I touched up my cutter while it was out of the chuck, it takes no time at all.



Here I am at Knocking off time looking at the next thing that has to be done, drill and tap the bed for the main bearing that will support the inboard end of the crankshaft. Good progress and no errors! Always a good morning when it's like that...

[Stanley]

Today I want to get all the drilling and tapping done and alignments of fixings tested. The first job is to address the inboard bearing of the crankshaft.



The same applies to the outboard bearing.



Quiet and careful tapping, taper tap first and bottoming tap to finish.



I have already drilled and tapped for the valve gear bearings, what I need now are the 3/8" 7BA bolts.



That's where it gets a bit annoying because the bolts supplied are a bit short of thread. I have to thread them down a bit further. Probably twenty minutes extra work.



Here we are at knocking off time. All the elements fitted finger tight to check alignment, they were all fine actually, no fitting needed. Now we can move forward. Beginning to look like an engine...

[chinatyke]

Beginning to look like an engine...

I love it when you get to this stage and it starts to look complete.

[Stanley]

Good Lad China, Yes, I do as well. It's all right seeing it in your head but it all starts to make sense when you see the parts in their proper relationship.

[BobH]

It is also so nice to see all that hard work fit together. However much confidence we have there is always that thought that it won’t all line up because we missed something.

[Stanley]

That's true Bob but I always have the Johnny Defence, "It won't be running 300 looms at t'Clough!".

[Stanley]

What I have on my mind now is painting the castings before mounting on a base and making and fitting the other parts. Before I do that the cylinder assembly needs to be finished, made ready for fitting so that's this morning's task.







It took almost an hour to address the steam chest and valve, largely because I made a mistake and bent the valve rod! These things happen I know but they are still annoying and time wasting. We're all right now....





The base has to have its gasket and jointing paste too. Luckily this was fiddly but straight forward.



Knocking off time, the piston ring is fitted and the top lid sealed. I can think about painting now..... A good two hours.

[Stanley]

The first job towards getting ready for painting is to remove all the parts that won't get painted making sure at the same time that all my witness marks are legible and agree.



No need for a lot of pictures. All the castings were cleaned up, all marking ink removed, mating faces cleaned and any sharp edges broken. Files, emery paper and diamond hones all had their place. I spent an hour and a half on this activity.



This was knocking off time. All the castings have been dealt with and are ready for painting which is the next job. That's for tomorrow....

[Stanley]

Amazon delivered my gloves yesterday which was handy because it means I have clean cardboard to do my painting on. No call for a lot of pics, there is no drama in painting! Here I am ready to start.





And here we are an hour and a half later. I have got a coat of paint on and where I have strayed on to the bits I want to keep bright I'll polish it off. I've cleaned my brushes and put them away. Now the bits of the engine can dry, I might have to take a day off tomorrow, drying and setting are two different matters.

[Stanley]

The paint dried and set quicker than I expected so no problem about handling the castings. I decided to mount the engine on a temporary base board so I could start making the parts for the motion and fit them as I went on.



I had painted over the seats on the bed and so the first job was to clean them off starting with a scraper and then moving on to emery paper.



The bed mounted on the temporary base. Now we can start building.





I had to run the tap through the threaded holes as they had paint in them.



Knocking off time. I'm ready for fitting the parts of the motion now. The first will be the crankshaft and associated parts. That was an enjoyable couple of hours!

[Stanley]

A good look at the drawings to start the day convinced me that the next move is the crankshaft. So, after making a fag packet drawing I found the piece of 1/2" stock that is hiding the shaft.





Normal turning. We know now that the crank fits. Remember all the sizes I end up turning for are the actual sizes of the parts that are going to be mounted, not always the same as the sizes on the drawing!



Turning the shaft and then parting off and finishing the end.



Knocking off time. We have a crankshaft ready for fitting. Only a short shed this morning as I had to go for my weekly Co-op shop.

[BobH]

I have also been doing a bit of painting. After finishing the little turbine before starting to decorate the study I put the Duchess chassis back on the bench and I did remember to empty the lubricator tank before turning it over . It is clamped into a swivel stand at each end. The boiler cladding is now on so a bit of crimson lake enamel has been applied. I have re-used the original cladding even though the late owner had said that he thought it should be replaced. Only one of the two axle feed pumps had been completed and plumbed in so I have made the pipe unions and valves to fit the second casting. Just waiting for some 3/4” hex brass to make the gland nuts. I have a piece on the shelf but it is very hard and from the colour could almost be phozzy bronze. Does anyone know how to tell the difference? It could just be a hard brass. Perhaps I should add here that the Duchess came to me in bits in several boxes. I am not exactly sure why the owner had stripped it so far. My guess is the he wanted to get at the regulator whose mounting screws are under the cladding. I have had it out and lapped the faces though it still passes a bit on hydraulic test.

[Stanley]

Morning Bob. I noted that you had escaped from the decorating... well done!
Phosphor bronze and aluminium bronze are both nasty and apart from turning them, the only clue I have ever had is the feel of the stuff and the colour. I've been lucky enough to work with railway bearing bronzes most of the time and It's lovely stuff. All my big engine bearings are cast in it.
I did once consider making a loco but decided against it. From the look of that chassis I did the right thing! Its looking good.
Regulators passing under pressure.... I've always had that problem in full size practice. When you think about it with the pressure coming from beneath the seat they are designed to pass even if you have a massive spring on top of them.

[Stanley]

I started the morning by polishing the crankshaft and matching the bores of everything that has to fit on it. That took longer than you would think. Then I cleaned the bores on the Crank itself and fitted it to the end of the shaft where it can sit all night before being bored tomorrow for the 3/32" dowel that Stuart recommend.



Here's where I finished the first part of the morning. Marching in the right direction.





Stuart supply a piece of rectangular bar stock to make the con rod but I haven't used it up to now. I'm going to use it for this engine so here it is marked up and drilled at each end ready for more work on it.



So at knocking off time after an hour and a half Here's where I stand. Not sure which way to go tomorrow, I'll see how I feel.

[BobH]

It’s all progress Stanley, good to see. I am hoping that when we get as far as steam testing with the Duchess that the regulator will close enough to prevent creep. It is a lovely model, designed by Clarksons of York who provided drawings and castings. It was originally built by a member of the Rochdale Model Engineers who had passed on by the time I joined. Richard bought it as a running model from the widow. The regulator is built like a slide valve on a cylinder where the pressure presses the slider onto the seat, so there is hope that it will work ok.

[Stanley]

They're good regulators once you get them tight. John's Annie had one like that.



And by the time I had bottomed her she would treacle over nicely but it took a long time to get there!

[Stanley]

First task was to put the dowel in the crank. I bedded it in shaft fit Loctite so there is no way that is ever going to come loose. Then I cut it down to the surface a filed it level.



Next job was turning the con rod out of the bar. Before that I had to put the 4 jaw on, measure up and mark and put centres in each end. I originally started to turn the centre to the 5/16" designed size and then I'd do the tapered ends after. But then I thought bugger it, it can be 5/16" end to end!



Here I am at knocking off time. there's been a lot of metal to remove.... Never mind, I'm not on piece work.

[Stanley]

Quiet and careful work on the con rod. This different way of making it is more complicated and slower but I shall stick to it! This morning I put a bit of shape into it and finished each end to the correct length ready for the next stage in the VM.



I sharpened the cutter, reset the mill to a slower speed, it's been set for brass for a while. And got on with reducing the crank end to it's correct thickness.



Here we are at knocking off time. Doesn't look like a lot of progress but I am not rushing and what we have is good! Tomorrow we'll have a crack at the clevis that fits over the beam end. A good two hours, now for a walk and breakfast!

[Stanley]

The first thing I tackled this morning was putting some shape into the crank end of the con rod. That's why I have a nut and bolt fitted to act as a guide so I could grind by hand.



Then I turned my attention to the beam end and the first job was to measure and mark and reduce the thickness of the stock. Then into the mill and some careful cutting.



Once I had the thickness right more measuring and marking, we have to cut out the centre to fit over the beam end. The difficulty is the more you reduce the stock the less you have to get hold of and the easier it is to crush the end.





I drilled two 3'8" holes and followed up by removing most of the metal with a 3/8" slot drill.



Then back to old fashioned ways, hacksaw and file and get to final size.



Knocking off time. the clevis fits the beam. I shall do some finishing on the rod but essentially we have it finished as far as cutting is concerned. Fiddly but a nice morning.

[Stanley]

I started out with a clear task, round the end of the clevis that fits on the beam end and I decided the best way to guide me was to have a marker at each side.



I thought the easiest way was to make the four spacers I will need for the Valve motion and use them.



I realised when I had made them that they weren't quite large enough in diameter so I sorted out two washers.



Here we are at closing time ready for grinding the circular shape onto the clevis. A long way round but look at it this way, I'm ready now and the four spacers for the valve gear and parallel motion are made and ready.

[Stanley]

I finished the work on rounding the end of the clevis first.



Then I made the pin for the clevis, 1/8" threaded 5BA.



Now I want the crank pin! Half an hour of careful turning and threading.



And here's where I finished up with the con rod and it's associated parts finished and fitted. That'll do for this morning.

[Stanley]

I made the body of the eccentric this morning but we have a problem with loading images.

[Big Kev]

Ian is on it and gallery upload functionality will be restored soon.