Loco about Locos

I'm just starting on a new loco - a 5 in gauge Jubilee - ‘Galatea’ It's a good looking  4-6-0 tender loco, with the added interest of three cylinders. Galatea is a preserved loco, so there's opportunity to add authentic detail. Also, the drawings are highly detailed, which will add to the interest. As a bonus, the drawings are all in Decimal - no more converting fractions ! A friend pointed me in the direction of Station Road Steam. They very kindly keep their old ads available. This is a very useful resource, and much appreciated . They have a group of pics showing an incomplete Galatea (long since sold).  Thank you, Station Road Steam. There's a lot of physical work in cutting the frames: I've chosen to buy laser-cut frames this time.  There are also a lot of castings available. Whilst castings have advantages, they also bring their problems - identifying/ establishing reference surfaces, and work-holding to name but two.  Given the choice, I prefer to work from s...

 I'v decided to resurrect my blog !! The Hall is long completed, named "User Hall", as there wasn't one!! Here it is in action : - I'm about to start on a new loco, a 5 inch gauge Jubilee, Galatea and thought I'd record the build.

The original drawings showed what I think is the Hawksworth tender - I've previously made one in 5 in gauge, and thought the Collett tender would make an interesting change. It has a couple of major challenges - the top of the sides are flared, and also the rear corners of the tand are very rounded, so a tricky compound curve is created where they meet. I took the basic dimentions from the drawings, and scaled the Collet specifics from a couple of photographs. The fact that the major lines of the tender matched up with the profile of the cab gave me some useful reference points. Then there's a raised extension which fits on top. I left a tab which I curved to match the lower part of the tender, and riveted and soldered the two together. The other tricky bit was the rivets -there are several hunders of them, and they're very prominent. My solution was to make the tender tank out of thinner brass than usual -about 22 gauge. (Another reason for this was that I had a couple ...

The frames were already cut out, saving a bit of sawing. I checked that all dimensions were correct, and cut out the buffer beam and drag beam, from angle section. It never seems to be truely square, which shows up on the insides, when the angle fixings are mounted. So I lightly milled them all over, which got rid of the mill scale at the same time. Also the angle sections to lock it all together. I clamped the angle iron in place, and drilled through from the fames. Only then, I marked of the length of these pieces, taking the dimension from the frames rather than from the drawings - at least this way, they all fit accurately. I worked on a surface table, checking that all was square as I went along. For the horn blocks, I milled the mounting surfaces to size, and riveted them to the frames, slightly overlapping the horn openings. then milled the horn gaps to size. This made sure that the horn slots were accurate and truly square. If I'd milled them completely to size before fitti...

I recently read the book 'How (not) to paint a locomotive' by Christopher Vine (ISBN: 9780955335907). It's full of useful information, and a council of perfection. I read a lot of the things I'd tried when painting the A3, and although I stopped short of what he'd done, I came to many of the same conclusions. I sprayed using a Pasche internal mixing air brush, using automotive type paints (NOT two-pack cyano acrylics, which absolutely need an external air fed mask. I used water based paints (sounds odd, but I'm told are the replacement for cellulose paints) , thinned with cellulose thinners. I started a very light coat of etch primer, just a token rub down, then grey primer. Finally, a few light coats of gloss. Once its cured - at least a week - I flatted down the surface with 1200 grit wet and dry paper. I then used cutting paste in two grades, and was amazed at the quality of finish I achieved. I've heard aerosol spray paints being recommended. I have tri...

Work has progressed - the boiler is now complete. The assembly sequence I used was as described in Alex Farmers book on boiler making - and, as it happens, his was also a GWR boiler, although bigger. As the assembly gets bigger, it always surprises me just how much heat it needs. I work outside, so can only work on wind-free ( and preferably dry) days. Also, I find it essential to use refractory bricks- without them, I'd never get up to temperature. Even so, it needed two good sized gas torches, and occasional oxy-propane, to complete the assembly. I couldn't do this alone, and gratefully thank George and Russell for their help. Where ever possible (and that's most of the time), we worked with pre-placed solder - its much easier than applying a stick, as it tends to melt - or at least sag - if you're not quick. We put rings of silver solder under the heads of all the rivet - stays in the firebox. As the solder flowed, each was grasped on the outside with pliers, rotated...

Some of my boiler making tools. I formed the taper barrel using a set of bending rolls. I decieded that the chances of cutting the sheet to exactly the right dimensions was pretty small - the copper stretches when rolled - so I left the sheet oversize, and planned to cut it after forming. I know this makes for less convenient cutting, but at least it wont be short. Just as well; after annealing and rolling, the taper ended up at the opposite end to what I'd planned - it didn't matter one little bit. So once it was almost to shape, I could work out exactly where to cut it. I rechecked the dimensions once I'd got rid of the overlap, and found there was still a little to file off. I drilled the strap and riveted it to one side, pulled the barrel up tight with a strap, and drilled and riveted the other side. Before doing so, all the surfaces were finally cleaned and covered with flux. I laid two strips of (high temperature) silver solder at the centre joint, and added some more...

I decided that I didn't want to cut holes in any of the plates until I'd formed the firebox wrappers - so I started on those next. One way to form them is to make a wooden template and beat the annealed copper around them. Or you can form the sheet using bars of the appropriate diameter, which was the way I chose to go ( not being an enthusiastic woodworker !) Once annealed, the copper is incredibly soft, and needs little more than hand pressure to start to form it. I used various formers, as the pictures show. This firebox has a combination of inside and outside curves (most do) which makes it arkward. I just bent a bit at a time, checking against the flanged plates. A good fit is important, as silver solder has no gap filling properties. When the copper stops bending easily, its time to re-anneal. It took me five or six heats to get the inner firebox wrapper to my liking - less for the outer. Incidentally, I deliberately left the sheets oversize; putting lots of bends and f...

I know several model engineers who wouldn't touch boiler making - it's not for everyone. You need several sources of heat - a lot of it, somewhere safe to work, and you need to be aware that - unlike most aspects of model engineering, it is possible to get into a situation where all your work - and expensive materials - are irrecoverably scrapped. I've got to say, I like the challenge, and satisfaction that its 'all my own work'. Then there's the lack of waiting time. Whilst its also true that there's a significant cost saving, this is definately not a good reason for doing it. I bought a kit of materials from Reeves- this comprises all the copper sheet, bar and tubes. You really do need to have the correct materials, all in good condition, and, these days, of traceable quality. Copper is interesting to work with. After annealing, its amazingly soft, and can easily be shaped - until it reaches a point where it work hardens. Its then time to stop and re-anne...

The frames were already cut out, saving a bit of sawing. I checked that all dimensions were correct, and cut out the buffer beam and drag beam, from angle section. It never seems to be truely square, which shows up on the insides, when the angle fixings are mounted. So i lightly milled them all over, which got rid of the mill scale at the same time. Also the angle sections to lock it all together. I clamped the angle iron in place, and drilled through from the fames. Only then, I marked of the length of these pieces, taking the dimension from the frames rather than from the drawings - at least this way, they all fit accurately. I worked on a surface table, checking that all was square as I went along. For the horn blocks, I milled the mounting surfaces to size, and riveted them to the frames, slightly overlapping the horn openings. then milled the horn gaps to size - if they were milled to size before fitting. This makes sure that the horn slots are accurate and truly square. If I'...

I've been trying to buy a panel saw (sheet saw?) for some time, but have been told that they havn't been made for many years. I was lent one a year or two ago, and found it much better for cutting large sheets of brass than the jigsaw I had been using. As I can't just buy one, I took an old wood saw, and ground off the cutting points. I then made up brackets to mount a fine-toothed 12 inch hacksaw blade, and drilled the saw blade to suit (A solid carbide drill goes straight through the saw steel) It might look a bit odd - but it works. Its as easy as can be to cut a straight line right through a 4 ft by 2 ft brass sheet. I might get round to tidying the saw up - the real thing is styled like a tenon saw without the tenon. And there seems to be no need for a blade tensioner because of the way the saw works.

I initially assembled the linkage with all the joints unpinned, so I could check that it all fitted and could move freely without any obstructions. Disaster!!! The angles that some parts of the motion were moving through were clearly wrong. The pendulum levers - which support the expansion link, and the link hangers were both visibly wrong. I checked all the components against the drawings - and discovered that the weighshaft -which supports the link hangers had been located in the wrong place on the frames- a dimension of 13/32 on the drawing had been set out as 13/16 in. (Actually, by the original maker of the frames -but I was supposed to have checked it). Everything else was correct - but -adding up the various dimensions on the drawing showed that the centres for the link hanger brackets were in fact wrong -by 1/8 in. Still, it made me read up and understand how Stephenson link gear is designed. To make matters worse, I'd drilled all the mounting holes around both items,and th...

The Hall uses Stephenson link gear mounted internally between the frames, and the cylinders have piston valves. Most of the valve gear components are straightforeward to make, although the eccentric strap might be worth a comment. The first step was to machine up a bit of bar to 1 1/8 diameter, with a lead that was a few thou less - as a go/ no-go gauge, and also for use as a jig. To machine up the eccentric,(from a casting), I sawed it in two, to form the two halves of the strap, then milled the surfaces square. I used a fine hacksaw blade, and was careful to mill off the least possible metal. Then I silver soldered the cut halves together again, and set up in the 4 jaw to bore the eccentric. (To set up work in a 4 jaw chuck, I use a dial gauge mounted on a tool holder, and TWO chuck keys on opposing jaws. This let me move the work together with the clamped up pair of jaws - much quicker and easier. A simple jig made sure that all four eccentric links were the same length.

The spacing of the coupling rod centres is critical to the free running of the loco. I measure each side separately and comparing it with the drawing. Any inaccuracies in making up the axle-boxes or in setting the crank-pins will show up here. I started by marking out the centres and outline on the rod blank, then drilled the centres, starting with a small centre drill, then drilling out at (say) 2BA clearance at one end, and 2BA tapping at the other. The rods tapered from 3/8 to 1/4 in. - i.e a taper of 1/16 in. on each side. So I marked out the centre line on the support bar, and another, offset by 1/16 in. I drilled and tapped a fixing for one end of the bar on the centre line, and attached the rod blank. Then I lined up the other centre on the 1/16 in offset line, clamped and drilled through 2BA tapping. Now I removed the rod blank, and opened the 2BA tapping hole on the rod blank to 2BA clearance. Also I tapped 2BA threads in the support bar and bolted the two together. I clampe...

Just by way of a change, some pics of my finished locos - not me driving! This is a 5 in gauge B1. And this is my A3 Pacific, again in 5 in gauge.