Dock Tank Deviations

[Alan K]

I've started building a Class 498 Dock Tank from the Caley Coaches kit. I think it's a rather attractive little engine, and as I've said before, I'm a sucker for outside cylinder locos....! This is not intended to be a detailed account of the build, but rather some ramblings about the 'deviations' (or perhaps the 'interesting' bits) I've had to make.
My preference these days is for split frame construction and CSB sprung chassis, but that's where things started to go awry! The recommended gearbox is the High Level Loadhauler Compact+. Foolishly, I didn't fold this up until I had soldered up the frames, which was when I discovered that the gearbox was too wide! What I had missed was that the gearbox fits, but only for a fixed driven axle where there are only slim axle bearings: with the driven axle mounted in hornblocks plus the CSB springing arrangement in place there is no room. So that was deviation no. 1...
I ended up unsoldering one side frame from the stretchers and adding lengths of 1.5mm brass bar to the stretchers and then resoldering, using the coupling rods to re-position. You can see the arrangement in this photo:

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Fortunately I had used John James's method of encasing the PCB stretchers with brass channel and this gave a strong soldered joint. The added brass bar can be seen at the left in this photo:

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But the gearbox still had to be narrowed! I made a jig from a wooden block into which (accurately vertical) holes were drilled using the gearbox side as a pattern to fix short lengths of rod as in this photo:

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This arrangement allowed me to cut off one side of the gearbox and re-position it further in, using the rods to hold it in place for re-soldering using short lengths of nickel silver bar. I had to do this with the Killin 0-4-2ST pug as well - Mr Gibbons offers many different gearboxes in his High Level range, but the ones which give my preferred 80:1 ratio are a tad too wide! But I seemed to have got away with it as it works fine!
So that's got me to this stage:

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The next deviation was a bit more complicated and rather time-consuming, but that is for another day - I've just fallen foul of the 'you'll have to log in again' carry on which has meant doing it twice!

Alan

[Jim Summers]

Alan,
I built one years ago and, like you, decided on split axles.
All went well till I glued up the some of the gears inadvertently and had to dismantle everything. The split frame arrangement didn't survive that.
It was still built, and is one of my favourites.

I look forward to seeing more of your progress.

JimS

[Alan K]

Deviation number 2 was a preference thing really. I like to have my model as close to what I can see from photographs, and that's where I had problems with the outside motion. There are lots of good photos with much detail of these engines, especially in LMS and later days. For example, here is a detailed picture (sorry about the odd angle):

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I'm sure that the kit as supplied can easily make up a working slide bar/cross head arrangement, but to my eye the connecting rods supplied don't look like the real thing (and especially when I've already adopted David Franks's coupling rods), the slide bars are tapered at both ends, there are prominent fixings for the slide bars on the motion bracket which can't really be added because the motion bracket shape is not quite right. There's also a large gland where the piston rod enters the cylinder. OK perhaps I'm being picky (!) but I ended up ditching the connecting rods, slide bars and motion bracket but retained the crosshead/piston rod casting....
I made new connecting rods using the dimensions of the supplied ones, as here:

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For reference the rod at the top is the one supplied with the kit.
I made the slide bars from 1mm square nickel silver bar with an extra layer soldered on the back to make up the thickness required to fit the crosshead. I made up a little wooden jig (shown at the top of the next photo) to hold the slide bars parallel before soldering to the backs of the cylinders. I also made replacement motion brackets complete with fixing points for slide bars. I had problems getting the shape right - the ones shown were the 3rd attempt!

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I decided that it was more convenient to have the cylinder/slide bars/connecting rod unit separately demountable, so the motion bracket slides into the etched slot in the frame and the cylinder bolts through from the inside of the frame. The unit mounted in place is here

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In hindsight, if I had to do it again I would make the cylinders front and backs as one unit in PCB and slotted into the frame as I did with the Killin pug. The reason I didn't do it that way was because I wanted to retain the front stretcher with the cut-outs for the Stephenson motion end caps.
Sorry I don't have a picture with wheels in place, but at the moment there are only 5 wheels - a long story!
So next stage is to build the body - hopefully without any more deviations (but you never know!). I haven't reached the stage where I need to decide whether the engine should be CR or LMS (the period which I'm modelling is that changeover period when both liveries coexisted. But I've just realised that these engines were all fairly new when LMS took over, so maybe I don't need to have smokebox rivets at all - even in LMS colours! I've seen a photo of 498 itself (the class leader) in LMS livery with no rivets to be seen - so I guess that maybe none of the class had major overhauls/new boilers in my chosen period. The later members of the class would only have been 2-3 years old when LMS took over.

Alan

[Alan K]

OK now back to business: 2 wheels with replacement plastic centres - now all 6 wheels can be properly quartered! Here is the assembly so far:

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Notice the clearance between the connecting rod and the top slide bar: this is the reason why there needs to be a taper!
This picture shows the front cylinder covers now attached.

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Maybe this is a minor deviation - I couldn't find any way to push out the rivets as per the instructions. They are much more prominent than that, so I ended up drilling out the etched rivets and soldering in short lengths of 0.5mm wire. I think it looks OK after filing down the protruding ends on the outside.
One of the difficult features of the arrangement is that the coupling rods thread through the motion bracket to reach the front wheels, which means that you can't remove the motion bracket without first taking off the coupling rods, and more critically the front wheel crankpin nut can only be put on with the outside cylinder assembly in place! So much muttering and sticking out of tongues until a technique can be found which doesn't involve having to find nuts which have pinged off.
But being able to add each outside cylinder unit separately has an important benefit when it comes to finding all the tight spots. I make it a rule never to connect up the motor and start running until I've been able to identify and cure all the tight spots by turning the wheels by hand and finger-propelling along the test track with minimum pressure applied. If there is a momentary skid when propelling along then the cause needs to be identified. In my opinion it's wishful thinking to expect these things to disappear by burnishing up bearings after motoring. And sure enough I found all sorts of problem areas - the slide bars needed some judicious filing to give better clearance with the cross-heads, and the motion brackets themselves needed a bit more opening out to remove rubbing of both coupling and connecting rods. With a bit of patience, I think I've identified everything. So I think I've at last got to the body building stage - hurrah!

Alan

[Jim Summers]

May you get a chance to get on with the body over Christmas, Alan.
That chassis looks really good with the chunky effect which I well remember on those. The effort with the rivets was well worthwhile.

Season's greetings,

JimS

[jimwatt2mm]

Alan, if you think the clearances are tight in 4mm, you should try it in 2mm!

Nice work as always.

Compliments of the season to everyone.

Jim W

[WCML55.68]

Thats going to look fabulous! Well done.

[Alan K]

Latest view with cab almost complete (but not fixed to footplate yet).

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I prefer to add details like cab aperture beading & lamp irons before assembly of the structure. It makes soldering the cab together a tad more tricky but with a little block of MDF sanded square and exactly the size of the inside, I was able to clamp up for soldering quite easily. But that's not really a deviation! This is it:

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This is a view of the rear window guards soldered up as per instructions. But the reality is that there were 8 vertical bars, as can be seen from this picture

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After a bit of humming & hawing, I decided that it didn't look right. But how to recreate a more realistic appearance? Needs thinner wire (eg 0.2mm copper from stranded cable) spaced 0.3mm apart, with the wires soldered to a thin spectacle plate fixed on the outside. But a jig is needed to hold the wires in place while soldering together.

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From left to right, wires in place in jig (cuts made with the piercing saw on the reverse side of a piece of PCB), soldered upside down to spectacle plate and ready for trimming, and completed window guard. This will need to be fixed to the cab outside with epoxy as I won't dare to try soldering it! This is how it will look.

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Still have to fit cab floor and fixing points for reversing lever and brake standard before soldering the cab assembly to the footplate, then it will be boiler and side tanks...

Alan

[jasp]

Alan
Your attention to detail is amazing.
Thank you for sharing.
Jim P

[Jim Summers]

Beautiful work, Alan, and a couple of neat tricks.
Wish you hadn't told me the correct number of bars, though. I have just counted the number on my model . . . .

JimS

[WCML55.68]

Thats going to look fantastic when its done Alan, youve achieved some incredible detail there, and being in brass, I bet the finished loco will weigh some, with good adhesion and haulage. Ive never worked much in brass like this myself only odd little bits. Although strangely Ive just made a jig from ¼" angle brass with two appropriate slots in the legs and soldered to a piece of flat brass, to aid cutting Evergreen plastic strip at 45° for the CR Dwelling House bay windows. Canny wait to see this finished, will it be all over black or did they carry blue with lining? or are you a later period?

Regards Paul.

[WCML55.68]

Beautiful work, Alan, and a couple of neat tricks.
Wish you hadn't told me the correct number of bars, though. I have just counted the number on my model . . . .

JimS

Jim,

I wouldny lose heart over this, and if you are thinking of altering to 8 bars, do some research first, they might not all be the same. My own research into cottages and houses has revealed an amazing number of variations. Im at present working on the pointy bay windows at front of dwelling house, they have very graceful machined stone quoinstones at sides and machined angled mouldings at the pointy end and very graceful curved overhangs just under the roof, Ive found three variations so far in the four houses visited, in the size and way that the machined stones have been made and installed, so theres no guarantees .... Im still smarting after the cottages back door error where they are clearly shown on the plans I have, it turns out out that they were planned to be installed and not there before.

Regards P.

[jimwatt2mm]

...... will it be all over black or did they carry blue with lining? or are you a later period?

Having only a steam brake, 'Beetlecrushers' were all always black, lined red /black/white in Caley days and then plain black in LMS/BR times.

Jim W

[Alan K]

Thanks for the kind words, guys!
I used up all my picture allowance on the last post, but there was one more. Making that little jig to hold the wires was a bit of a challenge. It needs 8 cuts which are parallel and exactly the same distance apart. It's difficult and regrettably I don't have the skill to do that freehand, so needed to come up with some assistance -in the form of yet another jig! Hopefully this drawing will explain how it works (I'm not quite sure why a piece of white paper turns out grey when it's photographed, but it's readable - just!)

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It's basically 3 scraps of brass soldered together to act as a guide for the saw cut made with the piercing saw blade. The first cut is done freehand, but all the other cuts are made progressively by fitting the 0.2mm thick 'foot' (which projects below the 'fence') into the previous cut, clamping it in place and using the side of the 'fence' to guide the new cut. Because the 'fence' piece is 0.3mm thick, that guarantees the spacing, and the cut width is the thickness of the saw blade ie 0.2mm. It may sound simple, but there was quite a bit of head scratching before that light-bulb moment!
A final 'jig' after the whole thing is complete is optional....

Alan

[WCML55.68]

Brilliant idea for the jig Alan. Ive made several jigs over the years for specific purposes and had one for a similar need to yours, my take was to use small blocks of brass of the necessary thickness soldered to a baseplate at the correct spacing, and a similar row at the other side. Speed was of the essence to avoid disturbing the previous joint. Then the wire could be just wound and some tension placed to to keep it straight. If I can find it ....

Will you be able to apply the red lining as mentioned in Jim Ws post? In my own experience its probably the hardest of all the modelling jobs and theres one thing for sure, a bad coat of paint can ruin a good model, and likewise a good coat can make an indifferent one. Thats one big advantage of my own BR days, liberal coatings of dirt.

Regards Paul.

[Alan K]

Haven't quite decided yet re lining Paul. Because the period I'm modelling is early LMS it gives me some licence to have engines in either CR or LMS livery because the LMS were tardy in repainting immediately. I think some of the smaller less important engines stayed in Caley colours until the early 1930's. At the moment I'm minded to have early LMS livery, which would mean no lining at all, but I've still got time. All that's fixed so far is that it won't have visible rivets and it can't be either of the McIntosh locos as the kit is for the longer bunker version.

Alan

[Alan K]

I've used brass dress-making pins to make the tapered cab entrance stanchions before, using the head of the pin to form the base. But the weakness was always where the flattened pin head gets soldered to the footplate - I've lost count of how many times the joint came adrift due to subsequent handling. This time instead of just flattening the head I found there was just enough material there to turn a tiny pip on the end which fits into a hole drilled in the footplate. Makes a much stronger joint! The position of the hole is critical, but a slightly larger hole gives some wiggle room...
You can just about see the pip in this picture - unfortunately my little camera doesn't allow a bigger magnification.

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The stanchions in place can be seen here:

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Not a really a deviation, more of a gripe: the tube supplied for the boiler has been cut to length with one of those plumbing tube cutters which results in a bell-shaped end. Ordinarily that wouldn't be a problem if the end can be filed square, but unfortunately in this case there wasn't enough length to do that on both ends! So I had to use a lot of solder to fill up the 'gap' at the front underneath the smokebox wrapper as can be seen here:

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I decided to make my own smokebox door and handle, a larger version of how the Killin pug was done. In my box of brass 'bits' (did I mention before that I'm a brass 'squirrel'?) I found a knurled brass threaded knob, a slice of which would give me the right diameter after a bit of turning.

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From left to right: what was left of the knob afterwards, completed door and hinge, finished Lambie style handle.
The finished door epoxied in place can be seen here:

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A careful comparison of the 2 pictures of the front end will reveal to the sharp-eyed a different pattern of pitting in the solder below the smokebox door wrapper! I'll leave you to guess what happened when I soldered on the lamp bracket in front of the chimney....!
I'm almost ready to attach the side tanks, then I've got the rest of the brass castings to contend with, but I've taken up all the picture allowance so that will have to await another time.

Alan

[Jim Summers]

More great stuff, Alan.
That is a neat use of the dressmaker's pins and new to me. And it looks so much better at footplate level, where my clumsy blob of solder or Araldite has to be sculptured.
Looking forward to those next photos.
JimS

[tony brenchley]

I have a box of nickel plated dressmakers pins 0.6mm diameter x 12mm long for the parallel section discovered at a French market a few years ago. Would look better than brass and I have enough to share them if anybody wants a few. I will try to remember to bring them to the AGM

Tony B

[JimG]

If there's a big run on them and you run out Watkins and Doncaster do a 0.65mm Entomological plated brass pin which could do the job

https://www.watdon.co.uk/acatalog/insec ... ories.html

They have a much larger range of stainless steel and blakc enamelled steel pins shown on the same web page, but maybe not so easy to use.

Jim.

[Jim Summers]

Tony,
At the AGM, please lay aside some for me, preferably an even number. . . .

JimS

[Alan K]

The problem with using plated pins for this application is that the stanchions on almost all of the CR tank engines were tapered, ie thinner section at the top and largest section at the bottom. To use these in the way I've described would mean abrading most of the plating off!
A quick glance at the photos of tank engines in Jim Mac's book suggests that only engines with doors didn't have tapered stanchions.

Alan

[Alan K]

Brass castings are often a mixed bag. I decided to make my own tank filler caps: photos show clearly that while the filler tube is set back slightly from the tank side, there is a prominent skirt around it which follows the curved tank top, and this isn't visible on the casting supplied.

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In the photo, from left to right: the body part is straightforward to make - brass turning domed on top and undercut below to represent the filler tube. The skirt was more of a problem, and I ended up using a short length of 0.6mm copper wire which was filed flat on each side to give a strip. The copper is dead soft, so could easily be wrapped around the base of the body. Next is the skirt soldered in place (and upside down) - notice the curved lip at 2 o'clock which follows the curve of the tank top. Finally the wooden jig at the right which has been filed down to hold the skirt flush with the base of the body for soldering.
This is the finished body in place (but not attached yet -still needs hinge and screw clasp)

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The method used was a variant of what I used for the Killin pug's tank filler, but a bit quicker to do.

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Again from left to right. I've found that the copper capillary tube which is used on fridges is very versatile. This one is 2mm OD and 0.5mm ID, and I filed it down to 1mm square for the body of the clasp.
The t-shaped screw which projects from the top of the body was made from filing down a brass track pin. Holding the pin in a pin vice makes filing to shape a doddle! Finally at the right hand side, the finished clasp ready for attachment. The hinge is just a short piece of 0.5mm brass wire.
This is the complete assembly epoxied in place:

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Note the step on the end of the boiler and the handle at the top in front of the filler to give the fireman access when filling the tank (or maybe he and the driver took it in turns!)
I haven't rejected all the brass castings - the backhead is very good and the dome is OK, needing only a little filler at the base. I had to work on the chimney quite a bit. The cap was a bit distorted (and oval) but I liked the shape of the base. It cleaned up better than expected, and I managed to get a nice seating on the smokebox thanks to a fair bit of undercutting underneath and some judicial taps with a hammer over a steel bolt of the right diameter!
I'm not happy with the safety valve though - the base looks OK but the rendition of the projecting Ramsbottom safety valves isn't right, and needs to be removed and a replacement soldered on.

Alan

[Alan K]

This is the Ramsbottom Safety Valve as supplied and the proposed addition

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And here is the modified item soldered in place:

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That just about completes the boiler fittings - only handrail to be done. I decided to re-work the skirt on the tank filler caps as it didn't get displaced enough by the curve of the top of the tank (see previous photo) - I think it's better now.
The brass castings for the front sandboxes would need quite a bit of filling to bring the sides up flat, and I'm tempted to use a small piece of hardwood as a former to fold up replacements...
Apart from that, the body is complete and I just need to revisit the chassis to attach rear sandboxes and brakes (and figure out a way of fitting which will allow me to drop out the wheels).

Alan

[Alan K]

Decided to use the sandbox castings after all, and add a thin wrapper to cover the shrinkage in the side of the box. I filed down the castings to accommodate - you can see in the photo that even that wasn't enough to 'bottom' out the shrinkage.

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But I didn't use the little castings supplied for the so-called McIntosh lubricators (which seem to me to be a bit 'underfed'!) and made my own using copper capillary tube. The main reason was that the stem needs to be a bit longer than the casting would allow and I didn't fancy drilling holes in cast brass to mount a pin.

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This might look like turning it the wrong way round, but I wanted to solder in the mounting pin first and the pin was too slender to support the turning of the lubricator shape the other way round!
The finished lubricator (and finished sandbox) are shown in this photo:

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That's the front end complete, including the handrail and the wretched LMS lamp-irons (there are 3 at footplate level at each end!). Just the steps to solder on and the body is complete.....

Alan