Tuesday 23 February 2021

More power for Pontesbury Sidings - building Canopus (pt 2)

When we last left Canopus we had a powered chassis - but with some issues. When placed on the track there was a mysterious short appearing to relate to the trailing truck. 

The truck had been built by the previous owner. I noted that it was a bit wide to gauge, but more importantly the side of the truck was within touching distance of the worm when the truck was over to the right. When running in reverse the worm was grabbing the right side of the truck frame and holding it and the wheel against the side of the chassis, and at the same time causing the other wheel to be in contact with the truck frame thereby causing a short - it was intermittent enough to allow the motor to turn but drawing significant current.

My solution was to trim back the truck frame so that it was completely free from touching the worm. In doing this the soldering of the frame gave way and I had to refabricate the truck, and I took the opportunity to narrow it slightly. To make sure the short didn't reappear I also added tape to both insides of the chassis and glued a sheet of 15-thou of plastic card over the face of the truck frames. 

Refabricating the trailing truck

I re-tested and found that this had cured the issue. 

In handling the chassis I noted that the soldering on one of the slide bars had come undone, so I had to revisit with the soldering iron to get a solid joint. Note to self - don't touch the slide bars, they are fragile!

To complete the chassis I decided to add a Branchlines 6mm x 12mm flywheel on top of the Mashima motor. This improved the running further as the flywheel eliminated the majority of electrical dead spots even at low speed. The chassis now runs well, if with a bit of gear noise running forward and with a distinct waddle running in reverse. I was happy to note that it was able to handle the Peco medium radius turnouts without any difficulty.

This brought me to the cosmetic side of the kit. 

To complete the chassis I soldered the reversing lever link and actuator to the lug on the right side of the chassis frame, with a piece of 0.45mm nickel-silver wire at the pivot point. I did not connect it to the reversing lever coming from the cab, but made sure the rods lined up; this will enable body and chassis to be seperated in future. I then added the castings for the trailing axle with thick CA.

I then cleaned the chassis with a fibreglass pencil and gently washed it with rubbing alcohol. As the chassis had lots of moving parts that I didn't want to mask for air brushing I brush painted the chassis matt black (Lifecolor) and highlighted the cranks red (Badger Modelflex - signal red).

Complete chassis with basic body assembly behind

Moving onto the body. The cab bunker and running plate had already been formed up, but had fortunately not been combined with the cab roof or tank/boiler/smokebox assembly. The first modification I needed to make was to the cab roof. The previous owner had riveted and rolled the roof nicely, but had also inserted the safety valve casting. As there was now a flywheel in the cab where the casting should sit, I had to remove the casting. Instead I soldered two short lengths of brass tube so they protruded above the cab roof as the top of the safety valves, but were flush inside to clear the flywheel.

I attached the cast saddle tank to the running plate / cab assembly with thick gel CA. This was quite tricky to get level as the running plate had been formed with a distinct hump, but there was not a lot I could do about that at this juncture. I found that the brass chimney casting is a distinctly odd shape, and I tried to improve this a bit by turning it in my improvised mini-drill "lathe".  Quite a few of the castings - both brass and whitemetal were badly formed - it looked like the mould parts had been slightly off-set in some instances. In cleaning up the brake standard the handle snapped off and I had to solder a piece of brass wire to the top of the whitemetal casting. 

I drilled holes in the tank for the balancing pipe which I formed out of brass wire - ignore the starting dimples in the tank they are in the wrong place, as the pipe is just forward of the tank filler. Then drilled holes in the side of the boiler to accept the injectors - I didn't install these yet, that would be after I had painted the body, along with the spectacle plates. 

The complete chassis with part complete body shell attached

Canopus stands next to Baldwin No.4 - very similar sized locos

The next step will be paint - but what colour? Canopus appears to have had a standard Manning Wardle lined green livery at the Pentewan Railway. Lined green appears to have been the standard paint scheme for most industrial and contractor's locos at the turn of the twentieth century - unless the customer had their own scheme. In RAF service she is reported to have been painted unlined black with what appears white lettering on the tank. This must have been a very light coat of paint indeed though as evidence of the old lined livery is clearly showing through. 

However, as my rationale for having the loco at all is based having been a Col. Stephen's purchase in 1923 I intend to paint Canopus unlined black with red beams and slightly rustic white numbering on the beams, like the rest of the SDR fleet. I will be numbering her No.5 (next in sequence after the Baldwins).

The final installment will cover paint and details.



Monday 15 February 2021

More power for Pontesbury Sidings - building Canopus (part 1)

As I have said previously the Shropshire Minerals Light Railway would have been a challenging railway to operate. If Col Stephens had inherited the SMLR in 1923 he would have needed heavier power than the WW1 Baldwins and Kerr Stuart Skylark he bought for the Snailbeach District Railway.

There were plenty of surplus locos in the aftermath of WW1 because of the extensive use of narrow-gauge railways in military supply, and also as public light railways had started to suffer road competition. At the time the ex-Pentewan Railway 0-6-2ST Manning Wardle Canopus was for sale at second hand dealer, in real life she ultimately ended up as a RAF Air Construction Corps loco before being scrapped.  Let’s just suppose that instead Stephens bought her for use on the SMLR – quite a reasonable assumption; he liked both a bargain, and Manning Wardle’s products (there were several on his standard gauge lines). At 2’6” gauge with outside frames Canopus would probably have been easier to re-gauge to 2’4” gauge than the 60cm gauge Baldwins.

Historic photo of Canopus in RAF service - Wikipedia Commons


The model

I purchased a Backwood’s Miniatures kit for Canopus off eBay a couple of years ago – probably paying a bit too much for it, but its long out of production with Backwoods closing down in 2016. The kit was one of the first of a breed of prototypical kits for 009 but is rather infamous for being difficult to build due to some flaws in the design. One of my favorite blogs documenting a build is this one: https://caffeine-train.blogspot.com/search/label/Backwoods%20Miniatures   The kit I bought was part built which was a bit of a risk, but what the previous owner had done had been done very well, but not without some issues.

The previous owner had made the frames and gearbox assembly nice and square and soldered them neatly. They had soldered the outside cranks to the axles, but the right lead crank had been removed, presumably to sort out a bind, so it was not a rolling chassis. The other main issue was the slide bar yoke. This had been split and patched to widen it, as its well documented that as designed it’s just too narrow to allow the lead crank to rotate behind the crossheads. However, the slide bars which are supposed to fold up out of the yoke had been snapped off on the left side – these would prove a “right swine” to re-attach.

The first job I tackled was the loose crank. As the others were soldered, I thought I better solder it back on. I attached the side rod on the left side with some of the tiny (16BA I think) nuts included. Then used the side-rods to judge whether everything was in quarter by eye – as my quartering tool wouldn't fit this type of chassis construction. Next, I slid the wheels on the leading axle fully to the right side of the chassis, and with the left side-rod loosely on the cranks I clamped the chassis into a helping hand. I swapped the bit on my temperature controlled 50w iron for a medium sized bit rather than an electrical pencil tip, as I find this much easier for soldering brass components. The whole chassis except the front left crank was submerged in a bath of water to ensure that the heat from soldering the axle didn’t melt the plastic wheel centres. I had two goes as soldering the crank – the first time the crank slipped just as I was taking the iron off it before the solder set. I then tested the chassis and found that it rolled quite nicely with no major bind. So, I slid the wheels back into place using a back-to-back gauge to get everything in line.

Next, I tackled the crossheads, one was already constructed the other was still a fret of parts. I needed to provide my own piece of brass rod to form the piston rod as it was missing from the kit. Fortunately, the previous owner had obviously read up about another of the kit’s shortcomings and had purchased replacement connecting rods of the correct length so that the crossheads didn’t foul at the end of each stroke. I found the crosshead fiddly to assemble, and had a couple of goes before I was satisfied it was solid. I used a razor saw to make sure the channels on both sides of the crosshead were clear of solder. I don’t like rivets in any shape of form so rather than riveting the connecting rod to the crosshead, I made my own soldered pin arrangement – which calls for some deft movement with the soldering iron and a paper washer to stop the solder flowing where it wasn’t required.

I then tackled the slide-bars; first reinforcing the still attached set on the right side of the loco with a fillet of solder at the yoke end. Then attempted to solder the loose ones on. I had several goes at this – and eventually got them to attach sufficiently straight. I inserted the cross-heads only to find I’d accidentally put the left side connecting rod into the crosshead assembly upside down. It meant that the lubricator on the big end was pointing down. I couldn’t face disassembling the whole thing again, so as the connecting rods are otherwise plain, I just cut the etched lubricator off and filed it flush. I then attached the crossheads and slide bar yoke assembly loose into the slot in the frame. Trialling rotation, I noted that space behind the crosshead was still very tight indeed. I decided not to add a nut to the leading cranks, with the centre and rear nuts holding the side rods tight enough that there was no need for them on the leading axle.

The cylinders in the kit are whitemetal castings to be attached to the etched brass frame with thick CA or epoxy. The left side one had been drilled out by the previous owner, but the right cylinder only had what appeared to be a starter hole at one end. I attempted to drill this out with an appropriately sized drill bit, only for it to snap off. I tried the same from the other end only for the same to happen – there was something hard in there. It transpired that the previous owner had also had an issue with a snapped off bit and it was still stuck in there. This called for some major surgery on the cylinder. I cut off the cast in piston gland and managed to get the snapped off section of bit out. By now however the hole was much too slack for the piston. So, I drilled out the central hole with a wider bit and fitted a sleeve of brass tube securing with CA, building the gland back up with small sections of concentric brass tubing.

I then tried to attach the cylinders to the slide/crosshead assembly and to the chassis, in the process of trial fitting I ended up damaging the left side slide bars. I decided to solder both ends of the slide bars – I turned down my iron and used low melt solder to attach the slide bars to the whitemetal cylinders. I found I needed to use low melt solder throughout this piece of work as it was too easy to get the whole assembly hot enough to melt other solder on joints not being worked on otherwise.

Once this fiddly piece of work was complete, I attached the connecting rods and trialled rolling the chassis before soldering up the crank nuts. I found that a little bit of filing was required on the inside of the cylinder glands to ensure that the lead cranks didn’t catch – despite leaving the lead axle crank nuts off.

With a rolling chassis I next turned to altering the trailing truck attachment. I added a washer below the chassis bolster and drilled and tapped this 0-80; I tend to use American thread sizes as I have modelled in US outline HO for a number of years and they are to hand on the workbench. A cut down 0-80 countersunk bolt attached the truck which the previous owner had made up.  I then attached the motor / gearbox assembly to the main frame, with the worm just clearing the chassis stretcher to which the trailing truck attaches. I it tested under power, and it ran reasonably well first time. Phew!


Next up was the attaching the electrical pick-ups. The sketch in the Backwoods instructions leaves a lot to be desired, so I rather did my own thing. Gluing two strips of copper clad strip to the lug on the top of the gearbox and the slidebar yoke. I formed wheel wipes from the springy phosphor-bronze wire provided, these are an inverted v-shape so there is a wire pick up running on both side of each wheel.



I tested the chassis under power on stands on the desk and it ran well, if slightly “dry”, it ran much better after I lubed everything up - Tamiya plastic-friendly grease in the gearbox and light oil on the axle bearings. However, as soon as I put it on the track it didn’t run well at all – there appeared to be some form of intermittent short. This appeared to be related to the trailing truck, as when the truck was removed the short disappeared and the loco ran sweetly.

I’ll cover resolving this issue and the next steps in a future post...

 

Saturday 6 February 2021

Pontesbury Sidings - Track and energy....

As I mentioned before I'm using 00 (1:76) scale and 9mm track to represent pretty accurately the 2'4" narrow guage of the real Snailbeach & District Railways (by the way the company itself couldn't make up its mind whether it was the Snailbeach & District Railways or the Snailbeach District Railway - they appear to have used both).  

The SDR used light flat bottomed rail spiked to timber sleepers throughout its history. As much of this time was spent scrimping and saving, and there were no passengers (at least officially) to please, track maintenance was the bare minimum. Its documented in the Col Stephens era that when one rail head started to wear or shear the rail was often simply turned around to use the other head as the running rail - so they could get the maximum life out of each length of rail. Far from the prying eyes of the Railway Inspectorate speeds were low and derailments frequent - especially of the badly re-gauged Baldwins. Photos show that weeds, soil and cinders were holding the track together - but that's why we modellers like narrow gauge railways, it's lots of great "character" to model. 

To model this dilapidated state I used Peco 009 "crazy" track throughout Pontesbury Sidings using their standard 009 medium radius turnouts. There's nothing fancy about how the track was laid its just glued with PVA directly to the ply surface - no need for a cork road bed to simulate a yard of washed ballast here! Ballast, or rather dirt is up and over the sleepers in a lot of places.

I did spend some time painting the track, and nothing looks worse in my mind than shiny plastic sleepers and un-weathered rail. Before ballasting I painted the sleeper a dark muddy brown colour with a mix of low cost acrylic paints designed for school use. I then picked out some sleepers with a series of lighter colours to simulate newer untreated or very old weathered sleepers. I contemplated adding etched brass joint bars at appropriate intervals, but decided that it just wasn't worth the effort. So I next painted the rail sides a series of different rust colours, before giving everything a dry brush of a light grey - it highlights everything. 




Then came ballast and dirt. For the highly compact areas like the transhipment wharf I initially experimented with DAS modelling clay, as recommended by Chris Nevard. I am really fond of Chris' work and can stare at one of his micro layouts for quite some time even if nothing is moving. In this case I wasn't 100% keen on the result of the smeared DAS and ended up doing a lot of blending with a variety of paints and granular materials - my favorites being sieved garden soil and coal ash from the household fireplace. I find with all loose ballast and ground texture materials they need to be pre-wetted before applying dilute white glue. I use rubbing alcohol or meths for this as these break the surface tension but allow the the dilute PVA glue dry completely clear. Using water as the wetting agent with or without a drop of detergent gives everything an unrealistic shiny sheen. Water is also much more likely to make very fine materials (such as soil and ash) to go into a ball, which you really want to avoid.

For the standard gauge sidings I used Peco's new range of code 75 bull-head rail, it represents the chaired rail used extensively in the UK at the time much better than even their regular code 75. I contemplated making it operational - but ultimately decided that it was to be just cosmetic. I was therefore able to weather the rail and chairs appropriately - nothing's shiny in a weedy old siding on a branch line!



The layout is wired as one section with an isolating section only on the rear track of the loop. Its intended that the layout is run like the proptype, as "one engine in steam". It would lend itself to easy DCC conversion - but due to the way Dennis is built everything is currently analogue 12v DC and I have no plans to convert any of my 009 locos. I have built a home made power supply using an older Gaugemaster transformer and some other components, and mounted them in a floor based plastic enclosure. Two 16v AC feeds are brought up to the layout - one feeds the point motors and uncoupling magnates and the other goes to the 6 pin controller socket.  I use two interchangeable Gaugemaster hand held controllers – a model W (best for the modern coreless motored locos) and a model UF mounted in a handheld enclosure for Dennis (which needs the feedback controller to run slowly with its old open frame 3 pole motor). DO NOT use feedback controllers with modern locos like the Bachmann Baldwins unless you remove the PCB and speaker, even then the coreless motors don't like feedback much. I have mounted a momentary contact push button in the controllers so I can fire the uncoupling magnets - these are routed via the spare "pair" in the 6 pin socket.  At the moment I have used Peco uncoupling electro-magnets designed for N scale. I don't think these have quite enough "umph" and may swap them for a different brand; for home use I frequently just uncouple by hand with a small screwdriver. 



All 5 points are fired by Peco solenoid point motors attached directly to each turnout through the cast in mounting holes. This requires a slightly larger rectangular hole cut in the trackbed and a piece of thick paper is laid under the turnout to retain ballast with the point motor "legs" punched through it and into the locating holes. All the points are switched through momentary switches on a simple panel in the staging area. Two of the points at the far end of the loop were originally wired to fire together as a a crossover, but I had no end of trouble with one motor not firing properly in one direction that I ended up separating them onto different circuits. There are frog polarity switches mounted to all turnouts - both varieties of Peco accessory switch have been used due to space issues under the tackbed. 

Monday 1 February 2021

Winter update 2021

Well after a long period of silence it's time for an update.

Summer and Autumn are traditionally my off-season for modelling, there's too many lawns or, hedges to cut and weeds to pull up in the garden, and long country walks to do while the sun shines. It isn't usually until late Autumn that there is activity again in the train room.

However, like a lot of things this year - its been a bit different. Although I haven't had long spells at the workbench like I do in Winter, I was able to use the working from home time saving to pop into the train room now and then to deal with the next bit of scenery on Pontesbury Sidings. 

The results have recently been published on Alton MRG's virtual exhibition site here http://febex.co.uk/layouts/ with a full length "magazine style" article and photos.

Pontesbury Sidings is only the second layout I have made which has got anywhere near finished, third perhaps, if you count the 10ft finished scene on the White Mountain Branch (American HO based on the Maine Central). On that basis it feels gratifying that its rubbing shoulders with stunning layouts like Harlyn Pier and Harton Gill and not looking out of place. I am also excited to see one of my personal favourites Mannin Middle, a quirky but endearing take on the Isle of Man Railway, is booked for Alton's 2022 show.

So, look out for some more content here soon; there are some more tales about building Pontesbury Sidings, musings on trees, building the infamous Backwoods Miniatures Canopus kit, and articles on American and Japanese railways all already in draft.