Monday 27 May 2013

Relics

I took another trip up to the barn where I store all the junk I can't bear to throw away.  The main purpose was to dig out my box of enamel paints in the hope that they hadn't all dried out in storage (they hadn't, even though some of them must be thirty years old by now).  On the way out I bumped into a box which I had ignored because I thought it contained yet more of my late mother's gardening books.  The box moved in an un-booklike way, so I opened it and found a large quantity of model railway items that  I had either forgotten owning, assumed lost or thought I had flogged on eBay years ago.

The haul included various building kits and materials, four BachFarish maroon Mk1s, two Minitrix Gresley coaches, two locomotives, my old H&M Clipper (bought second hand in about 1978) and a little hand-held Gaugemaster controller.  So I set about trying to bring some of my old DCC-resistant locos to life, thinking that if I could get them to run I might be able to sell them.

First up was a Class 29 diesel, built many years ago using a Langley whitemetal body kit on an American Atlas chassis, and probably the only loco kit I ever actually finished.  I wired up the old Clipper, applied power to the track and the '29' ran after a fashion - jerky and hesitant, but it had never been a great runner so I wasn't expecting much.

Next for testing was an Ivatt 2MT 2-6-0.  An old Minitrix model, bought cheap as a rather battered non-runner and remotored with a Mashima can motor, back in the days when I still had steady hands and good eyesight and hadn't yet discovered High Commissioner whisky (available at all good petrol stations).  I put that one on the track and it just buzzed at me.  Ho hum.  I took the body off, found the motor had seized through lack of use, freed it off and applied a few spots of oil to the gears and bearings.

I then decided to try the little Gaugemaster controller.  The 2MT moved: I galloped it up and down the track a few times, then tried a bit of slow speed running.  Good as gold: no stalling or hesitation over the points, controllable down to a slow crawl, a slight wobble in reverse but then it always used to do that (probably a slightly distorted traction tyre).

I tried the class 29 again with the Gaugemaster.  Noisy, but good.  I don't remember it running that well ten years ago.  Metro-Cammell DMU (Farish body, Kato chassis) lurched forward a few inches and stopped.  Strip, oil, reassemble and I now had three exceptionally good slow runners.  By now I was on a roll, so I thought I would tackle the Class 26 (TPM resin body, Farish chassis, Hanazono 5-pole motor, split gears on two axles).  I dropped in the new wheelsets that I had bought and never fitted, dab of oil in the appropriate areas, and... same again.  No stalling, no hesitation, slow speed control as good as anything you might get in the larger scales.

So after an hour or so happily 'playing trains' I realised I have a problem.  The only reason I decided to go down the DCC route was in the hope of achieving the reliable slow running that had always eluded me in 'N'.   I don't need directional lighting, sound, or the ability to run two locos on the same section of track. Yet here I am with four old relics from the bad old days and a controller I found in a box, getting exactly the kind of dependable, consistent operation I wanted, without a single chip in sight.  Am I barking up the wrong tree?

Maybe not.  Two problems with the Gaugemaster.  Firstly, a whole lot of motor noise from all four locos.  Secondly, the motors are getting very hot even after a fairly short period of slow running.  Whatever waveform that little controller is putting out it is a long way from pure DC, and Japanese motors don't like it. I didn't have that problem with the J39 on the Dynamis Pro controller, and that has a Japanese can motor as well.

We need some trials.  Of the relics, the easiest to convert to DCC is the Class 26.  So I will fit a chip to it and see how it compares with 12V DC control, and report back.


Belstone goes all West Highland on me, circa 1967.  Class 29 pauses between shunting operations as a Class 26, newly outshopped in rail blue, runs into the station with a passenger train


Normal Working Resumed.  Ivatt 2MT heads an absolutely typical Border Country branch line train.


Sunday 26 May 2013

A sense of place

Sunday afternoon, and having mowed the lawn and pulled up a few random nettles to keep my landlord happy I settled down to some more useful activity.  First job was to make the trackplan alterations mentioned previously - lift and relay the bay platform and loco servicing roads, and slew the goods siding towards the centre of the baseboard to make more room for a goods platform.  All nice and easy.  I haven't reinstated the wiring yet as I am still minded to redo the whole lot while I have the chance.  It will be a lot more difficult once I start putting scenery in place.

Having done which I thought I would have a crack at constructing the first of Belstone's (very few) buildings. If you are looking to recreate the look and feel of a particular area, buildings are important.  Every pre-grouping railway company had its own distinct architectural style.  A good model railway should allow you to take an educated guess at the region it represents, without a single locomotive or item of rolling stock being visible.  And of all the various railway-related structures, probably the most distinctive are signalboxes.

Granted, some companies used off-the-shelf products by companies like Saxby & Farmer or The Railway Signal Company.  But most of them used boxes to their own design, and there was a lot of variety.  One of the best-known was the wooden framed box designed by the Midland Railway.  An early example of modular construction, it could be adapted to suit anything from a small branch line to a major junction simply by increasing the number of window bays.  The design was immortalised thanks to Airfix, who produced a kit in the 1960s for a typical mid-sized Midland box (actually based on Oakham) which must have sold in hundreds of thousands.

Likewise the North British had its own way of doing things. Their boxes were square, solid things with fewer windows than most other companies, and instantly recognisable.  So there was no way I was going to get away with a 'generic' plastic kit-built signalbox for Belstone.  I dug around in the scrapbox, found a pile of Plastikard sheets of various kinds (including embossed stone, slate and brick) and set to work with a Swann-Morton scalpel and some glue, as well as the Ian Futers drawings for Scotsgap signalbox.

After about four hours and a slightly burnt dinner, I now have something which is far from finished, has a lot of rough edges to tidy up, but is still unmistakeably a North British signalbox.  Here it is with one of my unfinished projects from years ago, a resin bodied Class 26 diesel on a Farish chassis, now rendered completely pointless by the Dapol model and so unlikely ever to be completed.


And here is an overall view of the layout showing the realignment work, as compared with version 1.0:



I am still not completely happy with the track plan.  In real life I don't think the loco servicing road would have been accessed via a headshunt off the bay platform.  More likely, given the available space it would have been through a facing crossover interlaced with the access points to the bay platform.  Oddly, Peco have not so far included this particular track formation in their Code 55 range.  But I think the revised arrangement looks better and more railway-like than the original, so I will try to leave it alone now.

Coming next - having managed to build most of a signalbox I will tackle the station buildings (same constructional techniques, just bigger).  I also need to decide whether to build the road overbridge from scratch or just use the Peco one.  Road bridges are a lot less distinctive than signalboxes, and if there is anything unusual or special about North British bridges I cannot see it.

Thursday 23 May 2013

The invisible turntable

No sooner had I finished that last blog post than I had a thought.  Turntables.  Scotsgap had one, so did Rothbury, Reedsmouth, Alston, and just about everywhere else in Northumberland where trains terminated.  Belstone would have had a turntable, only a little one to be sure, but it would have had one.  But where?

Perhaps Scotsgap again provides the answer.  The turntable and inspection pit were on the other side of the road bridge from the station and water tower.  In model railway terms, in the fiddle yard.  So instead of shortening the loco servicing road I need to lengthen it, to go under the road bridge and into the fiddle yard the other side (where, as it happens, there actually is a turntable, to reduce the need for handling small delicate locomotives).

The main problem with this is that I have deliberately spaced the servicing road well away from the running line, which means I will have to lift and relay the access pointwork and the bay platform road. Meh. That will teach me to make cocky blog posts about layout planning.  Lucky I haven't started ballasting yet....

A none too flat field

A long time ago I bought a book entitled 'Landscape Modelling' by Barry Norman.  Not the film critic and pickled onion seller, the other Barry Norman who built a rather fabulous layout called 'Petherick'.  Here's a photo of it that I found on the Web:

Petherick

My copy of his book is probably still in the storage shed, I'll have to dig it out.  But one of the points he made is that to be convincing, a model railway should be set in a landscape, not just plonked down on a flat board with a few pimply hills added as an afterthought.  Now I only have a space 4' x 1' to play with, which limits just how much Northumbrian countryside I can include, but I still want what little scenery there is to be convincing.

Another issue raised by Barry Norman, Iain Rice and others was the concept of managing sightlines.  The idea is to arrange scenery, buildings etc in such a way as to draw the viewer's attention to the middle of the baseboard and away from the edges, where the little world you are trying to create comes to an abrupt halt. So with these principles in mind I set about 'Belstone' with a marker pen and the May 2013 issue of Railway Modeller, which contains a set of 2mm scale drawings for the absolutely typical North British station building and other structures at Scotsgap Junction.  The end result being this:


The basic assumption is that Belstone station would have been built on a field on the edge of the town, gently sloping from the 'country' to platform end and from the back of the station to the front.  There aren't many flat fields in northern Northumberland, and most of those are next to rivers and prone to flooding.  So the North British would have had to make the best of what was available, and use gangs of navvies to clear a level space where the station and track would be.

The station is approached through a shallow cutting: the line then passes under a minor road bridge at the station entrance.  I will build this on a slight skew, which will naturally draw the viewer's attention towards the water tower and away from the back corner.  An access road then gently descends on an embankment to level out at the back of the station building at around platform level, with a sloping bank behind it rising up to meet the backscene.

The platform end is trickier as there are no structures in the foreground apart from a cattle dock. The best I can think is to have another slight bank along the end, and plant some trees along it.  Just one problem: I don't have enough space.  So I intend to cheat and extend the baseboard by an inch and a half along the back and across the platform end.  I will also have to make a couple of minor alterations to the track plan: shorten the loco servicing road by a couple of inches to make room for the embankment, and slew the goods siding across to allow a bit more space for a loading platform.

Buildings are easy (apart from the minor point that I have never scratch-built a building before).  Thanks to Ian Futers, pretty much everything will be Scotsgap.  station building (built as a mirror image to put the stationmaster's house at the buffer stop end, otherwise it will not have a garden), signalbox (at the end of the platform ramp as per Scotsgap, but narrowed slightly to fit between the main and bay platform roads), and water tower / coaling stage (again mirrored to put the water hose at the station end, so it will reach locos which arrive at Belstone tender-first).  Scotsgap also had an open inspection pit for oiling motion and other minor maintenance, but I am not sure this would have been positioned quite so close to the water tower.  If the driver was under the loco while the fireman filled the tender, and the fireman didn't shut off the water in time, the driver would get an early bath...

There will also be some coal staithes, cattle dock (I can't find any photos showing what if any fencing a North British cattle dock would have had) a weighbridge and hut (tucked in near the diamond crossing) and possibly a platelayer's hut somewhere.  I thought about putting an engine shed on the loco servicing road (Rothbury had one), but I reckon it would make this corner look a bit too crowded.  Come to think of it, Rothbury also had a turntable, and I definitely don't have space for that.

I plan to build the water tower first as this will give me time to experiment with constructional techniques before I get stuck into the bigger buildings.  I will probably build all the structures (including platforms) before I start any landscaping, so that I can arrange the landscape contours to meet them, rather than having to cut holes afterwards.  This is the first layout I have ever really put any thought into before building it, and I have to say I find it a very satisfying way of doing things.  Once you have made the big decisions (who built the railway, where and why) everything else flows naturally from that.  Previously I have started with something along the lines of 'I want a double track station with a goods yard, loco shed and branch platform' and then tried to bend the 'back story' into shape to fit the model.  If there is really a difference between a train set and a model railway (and most non-modellers would say there isn't) then it is probably right there.

Wednesday 22 May 2013

Grandad's wire

My grandfather spent most of his working life underground at Ollerton Colliery in Nottinghamshire.  One of the lesser known perks of the job was offcuts of detonator wire:  single core PVC coated wire in various colours.  He used to bring back carrier bags full of the stuff, and every layout that my father and I built in the 1970s and 1980s was wired with it.  He died in 1982, just a couple of years after retiring.  He was a lovely man, tall and solidly built with hands like shovels, and never an unkind word to say about anyone.  When I was eight or nine years old we used to go out by 'bus to Tuxford or Retford, and he would sit down and puff away at his pipe as we watched a succession of East Coast expresses thunder past. He was not a railway enthusiast but he encouraged my interest and always bought me a new model locomotive for Christmas. Alfred Silvester, 'Grampy', this blog post is dedicated to you.

Anyway, while I was hunting about for various electrical bits and pieces to wire up 'Belstone', I came across a tangled bundle of yellow wire.  Grandad's wire, the very last bit.  I cut it into three inch lengths, drilled lots of holes in the trackbed and soldered it to the rails in all the appropriate places.  Then it was just a question of turning the baseboard over and joining up all these wire 'droppers'.  I was going to give a blow by blow account of how I got the layout wired up and running, but that would probably lose me the few readers I have.  Layout wiring bores me, and will probably bore you too.

Also, even though the wiring is now in place and everything works, I'm not happy with it.  Messy, vulnerable to damage and difficult to trace faults.  I used a load of bits of wire salvaged from my last layout, which made it difficult to use any kind of colour coding, and the wire itself was rubbish (unlike Grandad's wire).  So at some point I will probably redo it, this time using thick copper wire busbars running the full length of the board - track positive and negative, and common returns for point motors and uncouplers.


Belstone rolls over to have its tummy tickled.  See what I mean about messy?


Most of the wiring was straightforward, following the basic rule for live frog points - always feed power to the toe of the point, never the heel.  DCC purists will argue that my wiring is all wrong, since most of the track sections are only 'live' if the points controlling them are set correctly.  But the ability to derail locos by running them against incorrectly set points is a feature of DCC that I can probably live without, and as I will not be having lights or sound in any of my locos I don't need them to be constantly receiving a DCC signal anyway.

The only really tricky bit was the live frog diamond crossing.  The instructions recommend using a DPDT toggle switch to feed power to the frogs, but I wanted to see if frog switching could be done automatically, and anyway it was late on Monday evening and I didn't have a DPDT toggle switch.  So I hit upon the idea of treating the diamond as two 'virtual points' back to back, and switching the frogs using a couple of SEEP point motors with built-in SPDT switches, the same motors that I used for the rest of the pointwork. Very Heath Robinson, but my 'Frankenstein switch' works just fine.  The motors are electrically linked to the point motor for one of the siding approach roads.  I have since looked into doing the same thing more neatly with relays, and found a double-coil DPDT self-latching relay that should do the same job.


The Frankenstein Switch - two point motors bolted together back to back

The big question - does it run?  Oh yes. Beautifully.  I did about an hour of testing with the J39, played about with the various CV settings on the DCC system, and I now have the kind of reliable slow running that I have never achieved before in 'N' gauge.  This is a great relief:  Belstone is, as I have said, all about shunting, which means reliable slow speed operation is critical.  I am now a True DCC Believer, but will try to avoid boring others on the subject.

What next?  I only have one loco, coupling issues mean I can't yet operate trains anyway, and the fiddle yard is still in storage forty mile away.  So my next post will be about scenery. Probably.

Monday 20 May 2013

Send in the navvies

Having spent ages messing about with points, point motors, uncouplers etc it is finally time to move on to the fun bit.  So yesterday morning, after a hearty breakfast, the V.I. Lenin Red Flag Workers Progressive Shock Construction Brigade swung into action with the aim of going from bare baseboard to running layout in a single day.

First step was to work out where the holes for the point motors and uncouplers needed to be.  I assembled the point formations 'dry', carefully aligned everything on the baseboard, marked out the point positions with a pencil, then stuck headless pins through the actuating holes in the tiebars to provide a marker.  I also marked the position for the electromagnets. Having lifted the track again I drilled holes in all the appropriate places, gave the baseboard a final light sanding and got the glue out.

My intention was to use PVA glue alone, with heavy weights and drawing pins to hold the track down until the glue dried.  However, having laid the point formation at the station throat, I realised I had got one of the points in the wrong place, and at this point I found that unsticking glued-down track is all too easy, at least with the glue I was using.  So I started again, this time using a mixture of PVA glue and track pins.  Once the track is ballasted I should be able to remove the pins which are a bit obtrusive to my eyes.

Tracklaying progressed reasonably smoothly, apart from the diamond crossing which needed two short sections of track to be cut to a very precise length.  Needless to say I screwed this up and had to have a second go at it.  Measure once, cut twice... By lunchtime I had all the track laid.  Incidentally, when using Code 55 track you need to fit dummy sleepers at the joins.  I found the easiest way to do this was to use a spot of Superglue to attach them to the underside of the fishplates before positioning the track sections.  I also found that Peco insulated fishplates are too thick for the dummy sleepers to fit underneath them, so I will have to cut up some sleepers and glue them between the rails to fill the gaps where I have used insulated fishplates.

Next stage was to fit my modified point motors.  A couple of them needed the baseboard holes opening out slightly (measure once, cut twice) and I ran into serious trouble at the station throat where there are two points next to each other.  It hadn't occurred to me that by putting the operating pin in the centre of the tiebar I would not have space to fit motors to both points.  I lashed up an extension using a Peco remote point motor base, a bit of steel wire, a brass tube and some Araldite, and that was that problem solved.

By now it was teatime, and after several fortifying vodkas the Shock Construction Brigade started on point motor wiring.  At some point I will need to build a control panel but for now I needed something simpler.  The answer was to attached a screw terminal block (or 'choccy block' as they are generally known) to the outside edge of the baseboard, run all the point motor wires to it and then use a probe poked into the terminal block to operate the points.  I wired the crossover points at the terminus end as a pair, also the points controlling the bay platform and engine shed road.  My box of bits yielded a Gaugemaster capacitor discharge unit, I connected up an old Triang controller to provide the power, and all but one of the points worked.  The rogue motor was binding on the hole in the baseboard even though I had already had a go at fettling it (measure once, cut three times) and with this problem sorted I now had fully working points.

6.30pm, and after taking the dogs for their evening walk I set about the really tedious job of soldering wire droppers to the rail sections ready to connect everything up. I needed to put in about forty of these, and the task was not made easier by using solder that was much too large in diameter.  Also my eyes were starting to get tired.  So in the end I didn't get any trains running.  I connected up the first few droppers, tested the track with the multimeter, found I had somehow created a short circuit across the rails, and gave up.  Wiring can wait until the next session.  

A few pictures:


Overall view, station throat is on the left.  Clive the greyhound is unimpressed.


The classic branch line terminus - run round loop, bay platform with access to engine shed, coal siding near right, general goods far right and cattle dock at the far end.  The only unusual feature is the short diamond crossing, allowing two decent length goods sidings in a small space.  I can't remember where I saw that, but I like it.


Metro-Cammell DMU waits where the platform would be, if there was one.  This is a refugee from a previous layout - a very old Farish product with the hopeless motor bogie replaced with a Kato chassis. A bit out of period for Belstone, but it gives some idea of the overall scale of the layout.

Wednesday 15 May 2013

Track hack

No, I still haven't managed to lay any track yet.  Partly due to other commitments, but also because I want, just once in my life, to show that I have learned from my previous mistakes, such as rushing to get some track down without thinking through all the potential problems first.  'N' gauge is not very tolerant of either bad tracklaying or poor electrical contacts.  Belstone, as a small terminus, is all about shunting, and without reliable slow running I might as well model it post-Beeching, with all the tracks torn up and concreted over for a car park.

I am using Peco Code 55 track with medium radius 'Electrofrog' points.  There are seven of these, plus a short diamond crossing to make a classic branch line terminus with run-round loop, sidings for cattle, coal and general goods, a bay platform for parcels traffic and a (derelict) engine shed with watering facilities for thirsty locomotives.  (I got hold of a 1;25000 OS map of the area and looked at the gradients on my proposed route.  Engines would definitely want water on arrival at Belstone.)

The main problem I have found in the past with Peco points is that they rely on a good contact between the switch and stock rails to conduct the current through the switch rails to the frog.  It only takes a small speck of dust in the wrong place to disrupt this.  So I modify them, firstly by bonding the switch and stock rails together on each side with small strips of phosphor-bronze soldered to the underside of the rails.  I then cut an insulating gap across the switch rails just short of the frog, using a thin slitting disc in a minidrill.  This needs a steady hand.  It means not doing it in a tearing hurry in poor light.  Also not picking up the wrong (thick) slitting disc and cutting half way through the rails on the first of your points before you realise what you have done, and not nicking the inner edge of one of the stock rails with the slitting disc. Ahem.

While I had the Dremel out I also cut away the moulded base for the clip-on Peco point motor, drilled a hole just off centre in the tiebar to take a Seep point motor pin (making sure I kept well clear of the over centre spring underneath) and shortened the ends of the tiebar to get rid of the moulded pip and hole.  I think the end result looks much neater, even before ballasting: see what you think.


SEEP point motors:  these have a single pole switch built in which is in theory ideal for switching frog polarity.  The problem is that they have a throw of around 6mm. The throw on the Peco point blades is only 2mm, which means that the built-in switch is acting over only a short part of its travel.  As I found on my last layout, this causes problems: even if you manage to get the point motor located dead central, electrical contact at either end of its travel is mainly down to luck.

So I looked at one of these point motors (which I salvaged from the last layout) and came up with a way to reduce the throw.  It uses a brass lever with a hollow brass tube soldered to it.  At one end is a hole which pivots on an 8BA screw and self-locking nut through a convenient existing hole in the point motor base (with an insulating washer to prevent it shorting across the two circuit tracks either side of the hole).  A slot at the other end engages with the actuating pin.  This is then cut short and the cut-off end secured inside the hollow tube.   Finally a couple of spacers (plywood in this case) are glued to the point motor base so the whole mechanism clears the underside of the baseboard.  The photo below hopefully makes this a bit clearer. I now have about 3mm throw at the actuating pin (plus or minus a bit of slop) which means the built-in switch should engage fully at both ends of its travel.


I also added a 6-way terminal block to make it easier to swap failed point motors at exhibitions, which is the only time they will ever fail (I have a couple of spares).  I haven't actually tested this mechanism in service yet.  I expect that over time the slot will wear, to the point where there is so much slop that the motor no longer has enough free travel to switch the points.  The pivot may also wear with the same result.  All I can do now is fit them, try them and see what happens.

Tracklaying cannot be far off now. Can it?

Wednesday 8 May 2013

Animal magnetism

Last time I stopped modelling, one of my works in progress was an under-track electromagnetic uncoupler to use with Microtrains knuckle couplers.  These are designed to use large permanent magnets sitting between the rails, but I didn't like that idea much.  The MT couplers have steel pins beneath them which need to be pulled sideways to uncouple: by drawing back slightly to allow the couplers to spring fully open, an uncoupled vehicle can be propelled to its final position and left there.  The couplers are neat and unobtrusive, so all I had to do was come up with an uncoupling system.

Well, after three evenings of messing about with solenoids, iron nails and lumps of steel I am no nearer to solving the problem.  I can't lay any track, because I would have to install the uncouplers first, and I don't have a design that works.  Part of the problem is that under-track electromagnets tend to pull the coupler pins down as well as sideways, which makes the couplers bind and stick.  So I am giving up.  Not giving up modelling, but giving up with the MT couplers.

I still want remote uncoupling with the delayed-action feature of the MT couplers, and there are several alternative systems out there.  Favourites seem to be the B&B and DG designs, both of which are very reasonably priced.  The B&B system looks less fiddly to assemble and the couplers come pre-blackened, but are only available through the N Gauge Society.  I was going to join anyway so I can buy some of their hopper wagon kits.

The great thing about the B&B couplers is that they work beautifully with simple single pole under-track electromagnets. So I can drill a few holes in the trackbed, lay some track and worry about installing the uncouplers later.  Time to get out the tracklaying tools.

Meanwhile, stuff on my 'worry about it later' list includes modifying SEEP point motors to give a shorter throw, wiring a live frog diamond crossing (I have read the wiring instructions until my head hurts and still don't understand them) and putting some legs under my baseboard so I don't have to clear the dining room table every time I want to work on it.


Friday 3 May 2013

Ballast - a possible solution

I had to go into town yesterday, so I stopped off at an art supplies shop and bought a block of DAS modelling clay to experiment with.  I took a six inch length of Peco Code 55 track, glued it to a scrap bit of chipboard then set to work.  Firstly I covered the entire track area with clay, pressed it into the gaps between the sleepers, then scraped off the surface approximately level with the tops of the sleepers.  Then, using a dab of water, fingers and a damp sponge I shaped the track bed so that the clay was just below the sleeper tops.

I carefully scraped any surplus clay from both sides of the rails and made sure the area in the 'six foot' either side of the track was nice and flat.  Finally I used a paintbrush, end on, to stipple the surface on one half of my experimental length.  For the other half I covered the trackbed in very fine sand, tamped it down then turned the whole thing upside down to shake off the excess..  I then ran my finger over the trackbed to smooth the sand into the clay.  I let the whole thing dry for a couple of hours, brushed off any surplus grains of sand, then sprayed a coat of satin black chassis paint over the whole lot (matt would have been better, but I just used what I had lying around).

Result?  The stippled area was disappointing - too smooth, and the clay tended to dip between the sleepers. The sand treated area was exactly what I was trying to achieve, apart from the slightly shiny sleepers due to using the wrong kind of paint...  I took a couple of photos of the test piece but they didn't come out too well which is a shame.  It took me about half an hour to ballast six inches of track, but a lot of that was due to experimenting with different techniques.  I reckon one block of clay should do the entire layout, and it is a lot less hassle than the traditional dry ballast and PVA glue technique.  Now if I can just get my patent electromagnetic uncouplers to work, I might actually be able to lay some track...

Wednesday 1 May 2013

I have a locomotive!

Today the postman brought bills, junk mail... a Bachmann Pro Dynamis DCC Controller and a Digitrax DZ125 chip.  So this evening I set to work trying to fit the chip into a Union Mills J39.

It wasn't easy.  The J39 is tender drive, with pickups on the tender wheels one side and loco wheels the other.  The loco body and chassis are a single solid casting, and the tender body is entirely filled with motor and gears. No room in front of the motor or behind it.  In the end the only way I could get it to fit was:

1.  Remove the plastic shrink wrap from the chip, and wrap it with thin tape (I used some Tamiya masking tape).  Snip the surplus lighting wires off the chip, tape it to the top of the motor, solder the two motor wires direct to the motor terminals, and connect one of the pickup wires to the tender chassis using the motor securing screw.  The other pickup wire goes forward to the loco and is secured in the same way as the original loco-to-motor wire which it replaces.

2.  Cut out the entire coal load area from the top of the tender.  I tried using Dremel slitting discs but they clogged too easily.  The tender body is cast in something a bit harder than whitemetal, but not much.  So I chain-drilled round the coal load, then used a slitting disc to finish the job, and tidied the edges up with a file.

3.  The drive unit will now fit in the tender body, but with the chip sticking up through the top.  It doesn't actually protrude too far, and I plan to gently heat and bend a thin piece of Plastikard to cover it, with a thin layer of finely crushed coal on top.

So having got the chip more or less installed I found a couple of old bits of track, soldered two wires to the end, connected up the DCC controller, placed the loco on the track and... nothing happened.  Even though the default address is 03 on both the controller and the chip, they didn't want to talk to each other. Having checked that everything was connected properly,  I reprogrammed the chip address to 02, and my J39 moved for the first time in about ten years.

I still had plenty to do though.  Firstly there was an intermittent short, which I traced to the tender sideframes being bent inwards slightly.  One of the non-pickup wheels was rubbing on the live frame. That was easy enough to fix, but then I found that, despite much cleaning of wheels and track, the loco kept stalling.  After more dismantling and fiddling I thought it might be that the axles on the loco were not making reliable electrical contact with the chassis.  I inserted a couple of lengths of bent phosphor-bronze strip in the channels that Union Mills thoughtfully provided above the leading and trailing axles, the result being a sprung chassis of sorts, and far more reliable electrical contact.  So I now have reliable slow running, at least on a short length of straight track...

I am still getting used to the stubby little joystick on the Bachmann controller.  It seems to increase loco speed far more readily than decreasing it.  Following the instructions with the Digitrax chip I played about with some of the voltage settings which made the loco more controllable, but I still ran off the end of the track quite a few times.  I think I just need to get used to a different way of controlling trains: I have always used H&M controllers in the past, with a large rotary knob.

So to commemorate the occasion, here is a photograph of Belstone's first train - a very unfinished J39 with a Peco mineral wagon, a Parkside kit-built BR 12 ton van, and a Peco tube wagon which I think dates back to the late 1960s.  Time to start thinking about buying some track and points.