SHED MATTERS 2

[Stanley]

I was determined to do better today so I went the long way round, starting with the basics. The first thing to do was improve the cutter. I gave it more rake and made sure it was a sharp as possible.



The next job was to set up the cutter to cut the correct diameter. Luckily the head on a 6BA bolt is an exact fit in the 3/16" guide die so used one to set the cutter.



I put a scrap piece of 3/16" in the chuck and cracked on. I didn't bother measuring the result of the cut. Here's the result, it threaded OK and a 6BA nut fits it nicely! The best test of all.



As a further check I polished the rod and tried it in the piston which is supposed to be a snug fit on the body of the rod. It's perfect.



Test OK so I cracked on with the rod.



All went well, I fitted the piston, it's a nice snug fit so I tightened it up because it doesn't need to come off again. Finishing touch was to chuck it and turn the excess thread off and reduce the nut slightly. There's plenty of clearance in the cylinder so the slight protrusion is no matter.



Here's a nice sight. The rod is a perfect fit in the cover and the gland and dead in line. Nice to see it coming together. Now for the valve rod and this could be a bit tricky......



I needed to reduce some 1/8" silver steel to 7/64". One way was to make a 1/8" die for the little steady, the other way was to file it down to size. I reckoned that I could get at least as good a finish with the file and diamond hone to I did it manually.....



I had to a bit of fitting on the valve chest and gland because the original design called for 3/32" rod but I have gone for 7/64" so I can thread it 6BA instead of the ridiculous 10BA in the drawing! A drill and a rat tail file took care of that and at knocking off time I had a cylinder with matching valve that only needs studding and fastening down. The valve rod is dead in line in the gland. Suddenly, we are on the verge of a working steam cylinder! Lovely and a nice satisfying morning's work.

[Super_7b]

Hi Stanley,

I saw a file on the lathe with no handle. You wouldn't, would you......?

Just messing.

BR

Mick

[Stanley]

Quite right and yes I did but very carefully and it was only a light polishing cut. Rules are made to be broken!



Today the steam chest gets my full attention. I want to put some finish on it and grind the valve face and the valve to a perfect fit. I need some room so I started with a tidy up!



Then into the front room, get the B&P slide valve cover and stick some Grade 0 emery paper on the flat surface.



The first stage was to make sure all the surfaces are flat. Best way is on a big, sharp flat file.



Next, all surfaces polished on the worn emery paper. This is good enough for the exterior and the mating surfaces of the steam chest and lid but isn't good enough for the valve face and the valve. For this, the cast iron lid and some coarse valve grinding paste is ideal. It gives the faces a frosted finish which while dead flat and smooth holds oil. Here they are frosted, I don't know whether you can see the finish but it is just right. Trust me, I'm a fitter.....



I assembled the valve in the chest and fitted the gland on. We're ready for the next stage but first I went into the treasure chest to find some 6BA studding......



8 studs cut off at 1" long. Note the piano wire cutters, just the right tool for doing this. Than a few minutes on a fine grinding wheel to clean the ends up and a 6BA nut run down them all to make sure the threads are good, particularly the start.



If you remember I broke my 6 BA tap when I was tapping the holes in the cylinder. I ground the shattered end down to make it into a good finishing tap but just in case I had a good search in the BA box and found another 6 BA tap. If you're wondering what the very fine taps are doing there I'm just demonstrating how small BA taps can be (If you've seen two, look again, there is one so fine it hardly registers on the picture!). In case you're wondering, I have pin chucks that can handle them as small as this!



I needed more tackle before I could get started..... It makes you wonder where it all comes from.



Then quietly away re-tapping the holes and fitting the studs by hand for a trial fit.



Here's where I got to at knocking off time. Enough for today! You'll note I have got one of the studs at the gland end partially fitted. (The studs registered perfectly with the holes in the chest, I got them right when I drilled them. I still remember some royal battles in the early days but I am better at it now. Care taken with that register pays off in the end.) When I did this last one (in one of the partial holes where I made the mistake) I realised that the best way was to do the final fitting on the 5 good studs in the chest, bedded in sealant, in order to make the best job of these two difficult studs. I shall do that tomorrow. In case you're wondering what I am going to do with the hole with the broken stud in, I shall leave that alone until we get much further into the making of the engine and winder. I shall fit a dummy, nobody will be able to tell. The chest will seal OK with the five good studs. It will run!

[Stanley]

I have thought about the way forward and I was right yesterday that what I needed to do was do the final fitting of the steam chest using the five good studs and deal with the others later. I have also decided to pack the valve gland and the piston rod gland and the piston itself. The front cover of the cylinder can be sealed and won't need to come off again. So, I started this morning by properly fitting the 5 steam chest studs and locking them with Shaft lock.



It's always nice when the Stag Jointing compound comes out! You know you are getting somewhere.



As I said yesterday, the studs are dead in line and it was easy to fit the chest.



The lid on and bolted down tight. No sealant under the lid, this will have to come off for valve timing. Then I packed the valve rod gland.



The next job is to fit the front cover and seal it but the set screws are too long. I decided that rather than cutting them down by guess and by god I'd make a little fixture which will ensure that they are all the same length and square. I'm making this as we knocked off.



You can see the problem here. I shall shorten all 12 set screws before I go any further. But that's for tomorrow. You may think I am slow but these jobs are all fiddly, need doing properly and rushing is the sure way to disaster!

[Stanley]

I started the day by finishing off the jig I was making for shortening the set screws. I finished it at 3/8" for the first six at the blanks end and then reduced it to 5/16" for the gland end as the cylinder flange was slightly thinner at that end. I countersunk each end of the thread and then set to. I screwed the set screws in tight , mounted the jig in the vice, cut the excess off with a Junior hacksaw and finished the end with a sharp smooth file. It worked like a charm.....



Some of the screws had smaller heads so I I made sure that they were all the same. The threads were slightly smaller on some screws and so I re-threaded each hole as I went along to make sure they were all dead in line.



Once I had done the blank end I replaced the cover without any sealant because it may have to come off again later. I reduced the jig and did the screws for the piston rod gland end. I got the Stag out for this because with a bit of luck it need not come off again. This cover bolted down tight and the excess sealant cleaned off.



Time to address the packing of the piston. This is my favourite method. Put what you think is slightly too much packing in and compress it as tightly as you can with the clip. The idea is to finish with the packing slightly too big for the bore. Make sure you leave a small section of the piston peeping out at the bottom of the clip.



Grab the cylinder firmly in the vice, oil the bore and enter the rod in the gland. Then feed the bit of piston you left poking out into the bore and go brutal, using a suitable piece of wood, belt it into the bore. It will go in and the sharp end of the bore will cut any excess off. If you have got everything right you will find the piston is solid in the bore but don't worry, it will free up easily enough when it has to. Clean the excess off the bore, put a drop more oil in at this side of the piston and fit the cover with no sealant.



Now you can pack the piston rod gland and screw it down tight. As a finishing touch I took the excess off the valve chest lid studs and this is where we finished up at knocking off time. This cylinder is almost finished. There will be some small titivating jobs later but essentially the hard work is done. Now I need to have a think about what I do next..... Lovely morning, repetitive and fiddly work but very soothing and no mistakes!

[Stanley]

I was a bit late in the shed this morning and the first thing I had to do was decide what to do next. I could go down several routes and to be honest I felt like machining some BIG bits (relatively!) like the winch drum or the flywheel. But then I came to my senses and decided that the best thing to do is regard the engine and its immediately associated parts as the first goal that needed finishing. Having decided that it became obvious that the next task was to fix the cylinder on its bed and then go forward from there. The first thing to do was to make sure that the base of the cylinder supports was perfectly flat. Nowt like a big flat sharp file mounted in the vise to do that. Then I made sure the feet were a good fit in the channels on the bed.



Next I had to remember what I had tapped the base plate holes. It was 8BA so I sorted out four set screws and a spanner to fit them.



Having got them sorted the next fiddly little job is to clean up the surfaces of the feet where the nuts will be. I deployed the Dremel and an assortment of small files. Incredibly frustrating! I was on with this when I decided it was knocking off time. Patience Stanley!

[Stanley]

I have been thinking about the problem of cleaning the top side of the feet up and came to the conclusion that one of the oldest fitter's tools would do the trick. These Eclipse scrapers are brand new, I got them at Williamson's in Oldham for nothing. It didn't take long to get the feet reasonably flat.



Then came the really fiddly and annoying bit, getting the nuts on the studs and tightening them down. It was 08:30 before I got in the shed and 09:30 by the time I got these started and tightened down. I can tell you now, they are not coming off again!!!



I want to fasten the base and cylinder down on a piece of wood to take most of the bend out of the casting. I have screwed set screws into the underside of the bed plate to form the cylinder holding down studs. No way I am going to cut the heads off these so I put four recesses in the bed board.



Next job was to file the sides of the steam chest lid down to a perfect match with the chest. Next job was to make sure that the valve and piston rods were able to move in their packings.



I forgot to mention that I had screwed the bed plate down to the board. This hasn't taken all the warp out of the bed but I can deal with that by clamping while I am doing my measuring and fitting. So this is where I knocked off this morning, ready to decide what to fit next. We are on the way to an engine!

[Stanley]

There are two ways of looking at this morning when no machining at all was done. I've either been wasting my time or doing essential thinking and preparation for going forwards. I prefer the latter. I wanted to get a clear idea of where I was going so I had a sort through the castings to see what I had and what was to make. Long periods of studying trying to make sense of the drawings. I thought I had got there but then realised I had a problem in that the secondary bed casting doesn't seem to match the existing primary bed.....



I shifted operations into the kitchen and brought up the video of the engine running and compared the images on the screen with what I have in my hand. I eventually reached the conclusion that the casting was OK but it was the design that is peculiar. For some reason the secondary casting overlaps the primary. The only reason I can think of for this is that the bloke who did the drawing is trying to replicate the original engine. My feeling is that I need to have a think and perhaps re-design the solution on the drawing. I was also looking at the bracket that supports the tail of the piston rod and its associated crosshead (Which I will have to make, there is no casting). When I came to this conclusion I realised that the present mounting on the plywood base which isn't strong enough to counteract the inherent distortion in the bedplate isn't going to do as I need to be properly lined up. So I decided that I need to have a proper steel bedplate. Only problem is I haven't got a piece of steel. So I have mailed my mate Terry and shouted for help. I want a piece of 1/4" plate 11.5" X 3.5". I can't do anything serious on the erecting front until I have it. OK I could do things like turn the flywheel or the winch drum but I don't want to start on that side until I have the engine and its associated parts near completion. It looks as though I shall be catching up on my reading until I hear from Terry...... Not where I wanted to be but this is the best way forwards.

[Stanley]

Update. I shall not be held up too long. Terry has responded and I shall have my plate before dinner on Monday. It's nice to have friends!

[Stanley]

There will be no shed until Tuesday when I shall have the steel for the bedplate. I have decided against doing any machining until I have the cylinder properly mounted so I can do accurate measurements. I shall have two reading days! The rest will do me good.

[Stanley]

Terry came up trumps. We now have an engine bed. Progress is assured over Xmas!

[Stanley]

We start again on the build! I was late in the shed and was interrupted by comms from Oz but we managed to get a bit done. What I want to do is get the cylinder mounted on this steel bedplate which is permanent. If you look carefully you can see how the bow in the bedplate is pulling the plywood base into a curve. I want to force it to lie flat on this steel so that I can measure accurately for the motion etc. The small subsidiary bedplate is if anything worse than the main one. I'll decide later how to attack that.



I've taken the screws out that were temporarily holding the bed on the plywood and am getting the bed lined up accurately for the new bedplate. I shall then use the plywood as a template to mark the depressions for the heads of the set screws holding the cylinder down and the location of a few critical holes in the bed. I shall probably have to make an additional drilling as the largest bolt in the bracket that is the tail rod guide is also a holding down bolt and I need to have the bed flat while I fit it.



The easiest way to do this was with a hand drill. Then I drilled the depressions and mounted the cylinder and bed plate on the new steel plate to check hole locations. This was as far as I got when the phone rang, a call from Oz..... So in effect this is knocking off time.

[Stanley]

This is how I started the day. I got the bed firmly clamped to the bed plate and in the correct position. I'd already had a study and decided that 2BA set screws will be about the right scale for holding down bolts.



Next I took the cylinder cover off, removed the piston and the valve rod so I could get at the bolt holes next to that end of the cylinder.



I drilled the holes I could get to using a 3/16" drill in the old Black and Decker.... This drill has certainly earned its keep, I must have had it for almost 50 years!



The next move was to get into the drill press and drill the locations out 4mm tapping size and then thread them without moving the quill.



Then into the vice to file the set screws off flush on the underside.



This was where I had got to at closing time. I have taken the other cylinder lid off and tomorrow I'll start by drilling and tapping the other holding down bolt holes.

[Stanley]

The task this morning was to install the rest of the holding down bolts. I soon realised that I had a bit of a problem, access to the hole locations.



The answer was of course long series drills! This one is a Number nine, just right for a 2BA tap.



As you can see I don't have many long series drills but I was incredibly lucky in that two of them were just the size I needed! Amazing how things like this sit in the box for years and then suddenly they save the day.....



Of course I hit the same problem when it came to tapping these two holes.... The answer was a tiny spanner and a lot of patience. This is where you break small taps!



I got there in the end but it was slow, a lot of withdrawing and blowing the hole out! Looks nice with all the bolts in place.



I filed the excess off the bottom of the bed and then set to to replace the lids, piston Rod and Valve rod. Looking like an engine!



The next stage is to install the piston tail rod guide and the auxiliary bed. I shall have to make the crosshead first but I offered the bracket up to the guide rod and it has all come straight now and the hole for the tail rod is going to be bang in the middle of the bracket.

[Stanley]

I haven't torn any trees up today, I was late in the shed, too much communication with Oz. I have done some thinking and realised that I needed to make the crosshead to go on the piston rod before I fit the tail rod guide. So I went into the drawing office, modified what it said on the drawing and found a piece of scrap steel to make it.



Then into Mrs Harrison and make a tidy blank 1/4" diameter.



Knocking off time, I have it all clear in my head and the stock is ready. It can wait until tomorrow.

[Stanley]

Tiny crank journal, 1/8" X 1/4"



I soon had them cut and the crosshead the right length.



Next job was to drill for the 5/32" tail rod, I went for 9/64". I can sneak up on it.



I crept up on it with a file......



The drawing calls for an incredibly tiny wedge and two slots. Forget it! It's going to get a taper pin!

[Stanley]

I had less than an hour in the shed this morning, lots of comms with Oz.... The job is to fix the crosshead to the tail rod. The drawings call for a tiny little cotter in an incredibly small slot. Bugger that! It may be an accurate representation of the original engine but I shall use a taper pin! They have never let me down. So I had to have a furtle and sort out a pin and a drill. If you are interested, I gave up on making the hole for the taper tapered. I simply measure the middle point of the pin and drill that size. Use a long enough pin and when you drive it in it will make its own taper and you can cut the excess off. I've never known one come loose.



Here's the set up. A 1.8mm drill and I fitted the temporary bar so I could check it was square. I filed a small flat on the crosshead, popped it with an auto punch and then took the temporary rod out and drilled the hole. I can't see so well but all turned out OK. Near as dammit dead centre!



I decided I could get away with this set up. I was right, it worked fine.



Not a bad result......



The next job is to fit the guide for the tail rod. More to this than meets the eye and I will have to take out the piston and rod anyway. Not that this is a big problem. I checked the drawings, laid plans and knocked off. Tomorrow is another day. We have moved forwards and no cock-ups! That will do me.

[Stanley]

As usual, a final check that I have understood properly what I am doing. One bit of bad news is that the drawings have been reduced for copying and I thought I was working from full scale. Thankfully this has not caused any problems. My first job is to get some shape and square edges into the tail rod guide. This isn't as easy as it looks because it's such an irregular shape.



I had to set it in the vice simply by rack of the eye. (And I only have one good one.....) Very light cuts and an adjustment half way through got me a result.



I think you can see how minimal my hold on it was at times! Quietly away, very light cuts.



Once I liked the shape and measurements, I marked and drilled the hole for the tail rod, 4mm was just right as it happens. Then I set it upright in the vice and cut an oil cup in the top using a centre drill.



Here's where I ended up at knocking off time. The tail rod guide looks OK. All the edges broken on it. Notice that I have also milled the base of the stanchion that will carry the drive for the valve on top of the cylinder. I am not doing anything further with it at the moment because I can see problems and a re-design of the valve drive will probably have to be made. We'll see later....

[Stanley]

Despite what said at closing time yesterday, I had a good look at the rabbit and came to the conclusion I need to do something about the valve rocker shaft bracket because Ideally the holes need to be drilled and tapped in the bed plate now while I am doing the others for the tail rod bracket. I spent a long time trying to get some clues about positioning from the drawings but failed to reach any satisfactory conclusion so I decided to use my head and adjust everything else to suit once I reach the rocker shaft stage. The first thing I did was mill the top dead parallel and square with the bottom face. Then I spent a while with the file cleaning the ragged edges of the casting, particularly the holes in the bracket and broke all the edges with a coarse diamond hone.



I need the internal face of the base flat and parallel with the bottom face. I had to take one jaw out of the vise to get it set up properly but after that it was a simple job with a small end mill to get my face internally. Then put the jaw back in place and fit my normal 3'4" cutter.



Another study and I decided on the position of the bracket and the spacing of the holding down bolts which are going to be 4BA set screws. Once I had the bracket marked up and popped I transferred those drillings to the base. I have worked out how to convert my jobber's tapping drill to the equivalent of long series but that's for tomorrow! My head is all over the place of course so I took particular care to double check everything. I think I have it right and the exercise was good for me.....

[Stanley]

This morning the target is to mount the rocker shaft bracket on the base plate. The first job was to drill the bracket 9/64", clearance for the 4BA set screws.



I hadn't got a long series 3mm tapping drill but a bit of imagination and a pin vice solved that problem.



I was reasonably confident about my choice of tap but just to make sure I drilled and tapped a piece of scrap to test it. As you can see, it's fine. This not the time for a cock-up!



I tapped the holes using the Draper tap holder.... such a useful tool, I'm so glad I bought it when I saw it!



There was no way I was going to get a spanner in easily to screw the set screws home so I cut a slot in the heads with the Junior Hacksaw, sharpened a screwdriver and there you are, dead easy. I can get a spanner on for the final nip when we are building.

[micktoon]

Good steady progress Stanley it is certainly looking like an engine now. Keep up the good work.
Cheers Mick

[Stanley]

Thanks Mick. Yes, as you say, it begins to look like a steam engine! Nobody would believe the work to get it this far would they......



Today is the nice little job of getting the tail rod guide bolted down onto the bed. This involves tapping two holes for 4BA. The modern chart gives 3mm as the tapping size but to my mind that's a bit too big. I got this old book out, it must be about 100 years old. It was published by Marshall and by George Gentry who was one of the main contributors to Model Engineering. It's got all the old threads in it (including cycle thread) and give the tapping drills from the number series. I checked and the 34 is about 5 thou smaller than 3mm so I used that and it was a lot better.



Another benefit is that the number drills are slightly longer than metric ones. I thought I was going to have to take the piston and rod out to get to these two holes but by pinching the grip in the chuck a touch I managed to get away with them.



I marked the bracket from the holes and drilled for clearance.



The front web was interfering with my 2BA bolt head so I did a bit of trimming.....



Again, I got away with tapping by ignoring the fact that the vise was interfering with the rod a bit, too far in for the tap to deviate.



The holes lined up OK and the tappings are tight so it took a bit of patient work with small spanners to get them snugged down. Just enough room for the spanner one flat at a time!



Nice! Rock solid and dead in line. I must have measured something right somewhere!



The next job is to fit this secondary bed. This is going to need a lot of thought and some careful machining. The casting is short of metal and nowhere near the right shape.... This is a job for tomorrow so I knocked off.... Steady progress..... and no cock-ups!

[Big Kev]

Looking good.

[Stanley]

Thanks Kev. It's coming together all right now I have started to ignore a lot of what the drawings say! You can't beat a good think and a coat of common sense.....

[Stanley]

One thing I have learned is that the drawings that I got with the castings are copies of record drawings of the original engine. Not everything on the drawings is applicable to the job of building it. This morning's task is a good example.... I have little doubt that on the original engine the base plate was in two pieces. The pattern maker at the foundry followed the drawings and made his casting for the model exactly as per what he was given. It would have made far more sense to cast the bed in one piece. But we have to work with what we have got and this is where I have to do some very careful thinking. This pic is a good example. If you look carefully at the cylinder end of the secondary bed you can see a tab that overlays the existing bed. I had a good think about it and could see no reason at all for having it so as you'll see, I milled it off.



Here it is going away. There was nothing straight about this casting so I set it up by guesswork and milled some straight and square edges on it.



I only managed an hour in the shed and here's where I ended up. I'm ready to mill the other edges square with what I have done but if you look at the left hand side where the square is laid you'll see a tab or bracket sticking out. I can't see any reason for it and so tomorrow I'll have a good study about it but I suspect it's going to get milled off. But I'd better make sure first!