Saturday 28 October 2023

Ashover coaches part 2: adding a brake

 Work has continued on the build of the Ashover coach kits. There are now five...

A couple of the kits came from a friend at the Sussex Downs group who was having a clear out, but with them was a partially assembled kit. After a little partial disassembly to resolve the issue I'd found with the floor width and to "open" some doors and windows, it was completed (front left in the photo below), except that the footsteps and the bogie brake gear are missing. The bogies can probably run without brake gear (only the lack of brake handles is noticeable) but as the wheels look a bit coarse I may pick up a new pair of bogies at some point. 


The final kit was built as a brake. After posting some options in the last update, my friend Tim Sanderson pointed out that he had built some variants of these coaches including a brake to the same design as my "option C". This involved an extra pair of doors (which I had left over from those I had "opened"), but the cuts were minimal and all joins were at doors or door frames. Tim had explained these conversions in the August 2002 Railway Modeller.


So armed with Tim's article I set about cutting as shown - the end door, panel, and first window were cut from each sides (opposite ends so they are the same end of the coach, if you see what I mean). The windows were then cut away, and the door/panel swapped to the other side of the coach to put the panel outer, and the door plus the additional door set into the side. I made the cuts with a scalpel (new blade), light cuts from the front then deeper cuts lined up from the rear, leaving a surprisingly clean cut.


As with Tim's conversion on reassembly new framing was needed over the double doors (in one piece) and between them and the rest of the coach (to match the other side of the doors). These were made using 40 thou (1mm) plasticard cut to strips the same depth as the coach side, the frame being the thickness of the plastic. There's no significance in the use of black or white plastic, just the scraps that happened to be on the bench!

One other change I made was to the door windows. The end doors on these coaches slide behind the blank panel, and the broad cross-member is probably related to the sliding mechanism. However, the luggage compartment doors would probably hinge outward as per a normal carriage door, there being nowhere the inner door could slide anyway. So I cut away the cross-member and made their windows into normal drop-frame carriage windows, with a couple of them partially open. Also as seen below, small pieces of plastic microstrip were added to the frames to represent the outward-opening hinges. 


Given the preservation era of Hexworthy I see this vehicle being mainly for the carriage of push chairs and prams, and to give access for wheelchairs, let's assume a big ramp is carried inside. So the saloon has the usual bench along 4 windows, ending in half-height partitions, then a space by the 5th window which could be for wheelchairs or prams. There's a partition separating the saloon from the luggage compartment but the double-doors would be convenient for disabled access. I do need to sort out steps for this carriage too, bearing in mind the double doors away from the end. 


Next I need to decide how to tackle the roof. It is tricky as the roof will be fitted last (after painting, glazing, etc) and needs to fit neatly, but with little support needs to be rigid enough without appearing too thick. It doesn't help that the doors and end seem very slightly lower than the top of the sides. 
  • Some kits came with a thin sheet of plastic, which I have curved by taping to a can then dunking in boiling water (left). It will need trimming to fit, but experience says this will need significant bracing if it is not to sag, and could still be at risk of warping. 
  • Alternatively, the tall drinks can cuts easily to form a pre-curved thin metal roof (middle). This won't warp, but would need some strength to prevent it bending or getting squashed in the middle, and would need sticking down very firmly. It also may be more tricky to add rainstrips to. 
  • Another option is the Dundas moulded plastic roof for the Vale of Rheidol coaches (right). This is about the right width and too long, so would need cutting down. It's a little thick but not excessively so, and rigid enough without bracing. However, the moulding has recesses just inside the end (presumably for the ends of the coaches they are designed for) and so cutting to length could leave a gap over the end. I only have a pair of these so would need to order more.


Sunday 22 October 2023

Uckfield 2023

Yesterday I was at the Uckfield model railway exhibition helping Robin Edwards with his O14 layout Tony's Forest. I've seen this superb layout a couple of times and it was a pleasure to operate. As the name suggests, it is set in a forest which is beautifully modelled with big trees, undergrowth and flowers. There's also a quarry loading screen under which wagons can be loaded. 


Uckfield has a reputation of showing high quality layouts, and this year was no exception. My favourite was Rodmell Green, a 009 layout by Allen Etheridge on its first showing. This showed industrial narrow gauge with appropriate stock and muted, gently weathered colouring giving a consistent finish. 


Inside a shed, the skips were unloaded using a mechanised arm magnetically lifting loads out. Allen said he'd been inspired by the method I used on Thakeham Tiles having seen it in use at Uckfield a few years ago, although his unloading arm was motorised rather than using a manually operated mechanism as I did. 


This year's show was in part a tribute to the late Iain Rice, who did so much to develop approaches to layout design and exhibiting through his books, as well as techniques for building finescale models. The show included no less than 5 layouts (in P4 or EM) Iain had built or been involved in building, including Hepton Wharf and Butley Mills which I remembered featuring in some of his books, and the impressive Longwood Edge, although my favourite was one of his later layouts Trerice. This is a compact and characterful layout with its China clay dries. I did see this layout with Iain operating at a previous Uckfield show, and it was nice to see it still being used in new hands. 


Another nice compact but interesting layout was Arcadia in the unusual S scale (1:64) by Richard Barton, based on Colonel Stephens practice. In this scale everything must be hand-built, and everything looked and ran perfect. 


Another compact and characterful layout was Ewe (OO) by Rob Gunstone. The track plan is simple, the same loop and two opposed sidings as Chris Ford's Dury's Gap, with a Wisbech and Upwell tramway setting on the banks of a waterway. The lush scenery threatening to overcome the tracks, grey big sky background, and nicely weathered trains worked together beautifully. 


In the last 15 minutes of the show I ran one of my O14 locos on Tony's Forest. I'd crudely fitted a pair of Greenwich couplings to my Hudson Hunslet in place of my usual Microtrains, which surprisingly worked with Robin's stock. It did look rather at home in the forest. 

So an excellent show, an enjoyable day, and a big thanks to Robin for letting me play with his layout. There are more of my photos of the event including other layouts here

Sunday 15 October 2023

Linda

Waaay back in 1993 I remember attending the Festiniog "Hunslet Hundred" celebrations as a teenager. The elegant lines of the Penrhyn "Ladies" made an impression on me, especially Linda. When Bachmann launched their models of the locos in Penrhyn condition last year it was clearly just a matter of time until the modern 2-4-0ST+T incarnations arrived.


So when I heard they had arrived, exclusively, at the Ffestiniog Railway shop I scraped together my savings and ordered Linda. There is something rather rakish I think about her longer cab roof and open tender. 


As with other recent Bachmann models, the detail is exquisite, with Linda's open cab showing off the cab detail nicely (but crying out for a crew!), and the livery and finish is very fine. Of course, it runs as well as it looks. This will look great pulling trains into Hexworthy - although I expect some subtle weathering may be applied, and it will need a crew. 


As with the other models of these locos, there is a firebox glow. A nice touch. Really, the only thing I don't like is the plasticky full load of coal in the tender. Why does it always have to be full? 

Both my models of the Penrhyn ladies together. Comparing them, the addition of the pony truck to Linda is barely visible, but the tender and indeed the re-profiled cab roof are obvious. Look closely and there are other differences - the addition of sandboxes, blower pipe, lubricator, vacuum pipes, drain cocks, and a conversion to left-hand drive (note the obvious reversing rod on the left side of Linda, found on the right of Blanche). Bachmann appear to have done their homework. 

Saturday 7 October 2023

Ashover carriages

Hexworthy will need some passenger stock, so I have collected a few of the Meridian kits for the Ashover Light Railway carriages. Bachmann are soon to release a ready-to-run model so I need to get on and finish my kits first! The kit is reasonably straightforward although I guess it is getting old as there is some flash to clean up, nothing too dramatic though. 


The first was built while demonstrating at Alexandra Palace earlier in the year, and the second at Amberly in the summer. It wasn't until I got to the third until I wondered whether I should open a window. I don't have a book on the Ashover but found a couple of photos in my library showed that yes, the side windows opened in the usual way, so a few windows were modified cutting out part of the frame with a strip of microstrip across (3rd window from right on the rear coach). 


The pictures also showed the doors open, they slid behind the adjacent panel. I don't know they they were left open when the train was in motion (I expect so), and I guess that would be frowned upon on a preserved railway, but nonetheless I thought it would be interesting to model the doors open on one end. Cutting them out wasn't as difficult as I feared, some planks were scribed in the floor and I added a strip of 40-thou plastic along the inner frame to represent the edge of the door recessed into the panel. 


I have picked up a few tips for assembling these kits well. First, the floor half mouldings are slightly too short and too narrow. The length isn't a real problem as when assembled with one side and one end then joined, there's a gap of about 30 thou in the centre, but that doesn't cause any issues. The width though means that if the sides are joined to the floor they will bow in, a strip of thin plasticard along one side of each floor piece solves that, checking that the side and end come together. Also, the tops of the body sides are prone to warping inwards. I've taken to cutting pieces of sprue to form cross-bacing as seen here, and also for later builds adding a strip of 40-thou plastic along the top edge. 

Opening the doors of one coach left me with a spare pair of doors, with one unbuilt kit left. While the Ashover didn't have a brake coach (they were vacuum braked so perhaps not necessary), I thought a preserved railway might have a coach adapted for wheelchair users, children's buggies, etc. So here's some photo-edits to consider how the final coach could be adapted.


Option A: A pair of doors at the end, these would have to be hinged rather than sliding of course. I could omit the vestibule partition to make an open saloon, with the right two windows and to the right-hand end, which would make sense for wheelchairs although it isn't really a brake/guards coach. The steps would need extending. 


Option B: I noticed the door is exactly the width of the window, so by cutting out a window the two doors can be added with an adjacent panel, looking more like a guard's compartment. The inner partition splits the coach 1/3:2/3 so would fit between the fouth and fifth windows, or the second and third, neither of which makes much sense. Blanking, frosting, or replacing the right-hand window with a ducket would make more of a traditional brake coach, but wouldn't help with wheelchair access.

Option C: As above but with the cut-out door and panel swapped sides to put the panel towards the end. Actually, I don't think this makes any more sense than B, and the steps might get more complex.

Option D: Including a window in the cut-out and swapped section would provide an observation end compartment (taking advantage of the end windows), albeit rather small, and there's still little space for a guard's compartment. Maybe the same with two windows to the right, with just three to the left and the double-doors just right of centre might make more sense. 

Thoughts welcome!

Monday 2 October 2023

The "Ultimate" fiddle yard - refinements and finishing

So, here's where I think the problem is. With the sector plate of the home fiddle yard (left-hand diagram) the latch arm is pivoted in line with the movement of the pin, so it's movement is perpendicular to the pin movement. However, with the traverser (right-hand diagram) the pivot must be set back, causing the arm to be at an angle, and more importantly the movement of the notch is not perpendicular to that of the pin. When the traverser is pulled forward (down in the diagram) the pin pushes the notch away easily, but when pushed back (up) as the arm moves the slope out of the notch is effectively steepened, requiring much more force to move it. 

It had become clear that no amount of adjustment of the shape of the notch was going to allow the traverser to release forwards smoothly while latching positively, and I couldn't move the location of the pivot for the latch arm. Therefore if the traverser was to move smoothly and not jolt so that trains were derailed, a latch-release mechanism would also be required. I gave this some thought since the objective of the latching mechanism was to make fiddle yard operation easy and requiring minimal intervention from the operator, the latch release would therefore need to be easy and instinctive to use one-handed so that the traverser could be moved with the other. That meant it had to disengage the latches at both ends of the traverser, and return to self-latching mode once released. 


This view of the underside shows the solution I came up with. 
  • At the top left of this view is a wooden lever on the front fascia of the board, pressing this down rotates a dowel "shaft" which runs across the board (top to bottom on the left of this view). 
  • The shaft rotates a wooden arm, the top of which pushes the aluminium latch lever back (left) away from the pins, releasing the latch. 
  • The lower end of the arm is linked to another dowel that runs along under the board (left to right in this picture), such that the rotation of the first shaft causes this dowel to push to the right
  • At the end of this second dowel another wooden arm is pushed against the aluminium latch at the far end of the traverser, releasing that end too


With the traverser deck removed the two dowels can be seen, with the wooden arms that bear on the latch levers. Pressing the lever on the front left of the board thus pushes both latches back and releasing the traverser to move smoothly. Releasing the lever allows the latches to spring back into place, and so the traverser will then slide into the next latch position.

This view also shows a wooden arm fixed to the deck on the left, this is a "gate" that swings out to prevent runaways from the traverser when it is pulled forward. Held with a single screw it simply pushes back parallel to the board as shown for transport. There is a similar gate at the right-hand end.   


Another refinement is this old bathroom door draw-bolt. The lower part is fixed to the supporting cross member and the upper part is on the front of traverser, engaging the bolt locks the traverser in place for transport. 


As seen in the photos above the fiddle yard board got a coat of the standard grey paint used on my recent layouts, to match with Hexworthy. The smaller home fiddle yard also got a coat of paint. I use grey wood primer from Wilkinsons (although a primer it has a nice finish), I guess I'll need to find another source when this runs out. Mind you, it's oil based, smelly, takes ages to dry, and is a paint to clean out of brushes, so next time perhaps I'd choose a water-based paint!


The paint really smartens the fiddle yard, although I have not painted the deck or moving parts. Here the latch release lever can be seen, as can the two gates that protect the ends of the traverser when pulled forwards. 

So the exhibition fiddle yard is now complete. It seems to work well in the brief tests so far, but will spend most of its life in the garage, I guess the real test will be when it gets used in anger. 

Of course, life might have been much easier if I'd gone for a simpler turntable or traverser, rather than combining the two. The original intention was to have the benefits of a turntable (fast turnaround with no stock handling) while able to turn it when used against a wall at home, hence the need to pull it clear of the wall. Now I can't erect this fiddle yard against the wall at home anyway and as rebuilt it can only turn when pushed back, but decided I might as well continue to use the sliding/rotating arrangement as:
  1. I'd already got the sliding/rotating assembly which seemed to work so might as well reuse it
  2. The traverser arrangement allows parallel tracks so I can fit more in - a turntable needs space for the tracks to curve at the ends, so less tracks in a given width
  3. It actually proved handy. Being able to slide it away from you and rotating it without having to get off a stool and move out the way is quite useful!
  4. The double-ended latching arrangement works with a traverser but wouldn't with a turntable. (I expect it could work with a turntable using a common return rail powered through the pivot bolt and a changeover switch for the polarity when turning, perhaps as microswitches set up to automatically switch)

Finally, here's the home fiddle yard in place with Hexworthy. The grey paint looks much neater, again the moving deck is unpainted. The pillar on the right is the reason for the L-shape fiddle yard and why the larger exhibition fiddle yard can't be used here. 

Sunday 1 October 2023

The "Ultimate" fiddle yard - Latching mechanism

The next job in the fiddle yard rebuild was to create a latching mechanism that aligns the traverser tracks to the entry track, and provides power to the aligned track. This uses the same sprung notch and pin arrangement as proven on Loctern Quay and the home fiddle yard for Hexworthy. 


First holes were drilled in the PCB near the end of the traverser deck centrally between each set of rails. Normally I'd fix the track after putting the pins in and line them up to the entry track, but here the tracks are already in place. I cut a jig from brass sheet to slide tight between the rails with a hole dead centre, then used the Dremel in it's stand to drill a vertical hole, first as a pilot then opened up to the size of the brass tube. The holes go through the PCB strip, the 5mm PVC foam deck, then the second layer of PVC foam that forms the protruding lip, this makes sure the brass pins are held very securely. 


The alignment pins are made from brass tube chopped into lengths of about 20mm to go through both layers of PVC foam and protrude about 5mm below. This tube was 3/32" or ~2.4mm diameter, not that the diameter matters that much. 


The pins are a tight fit through the hole so were tapped into place with a hammer, the top just protruding above the PCB, and are then soldered to the PCB. The PCB was gapped to one side of the pin so that it is electrically connected to one rail. The pins are all connected electrically to the right-hand rail looking at the end of the traverser, so those at opposite ends of the traverser are connected to different rails. The protruding lip has been covered in graphite to ensure smooth travel below the fixed end deck.


The components of the latch mechanism:
  • A spring taken from a soap dispenser as shown
  • A length of aluminium - in this case T-profile - with a pivot hole at one end, and a curve cut and filed at the other, with a V-notch at its centre. There are also 3 holes through the vertical web
  • A long screw which passes through a hole in the aluminium, through the spring, and into the block of wood which is fixed to the board.
In this way the screw acts as a limit stop, spring retainer, and tensioner, the three locating holes allow the spring/screw to be located at varying tension and leverage locations. Note that this fiddle yard has TWO sets of alignment mechanism, one for each end of the traverser.


From the underside the aluminium arm is bolted in place with the wire to one rail (labelled "front") connected to it via a washer, it is free to pivot in the horizontal plane. The wood block is fixed to the board too, with the spring between it and the arm pushing the arm away. The long screw both locates the spring and acts as an end-stop for the arm, in this view the arm is at its furthest travel with the end between two of the five brass locating pins. 

When the traverser slides the pins push the arm back until they drop into the V-notch, being a round pin in a vee they locate the track, and being metal they conduct the power to the rail.

This just shows one end, an identical mirror-image latch is provided at the other end of the fiddle yard with the arm connected to the red wire. 


From above with the traverser pushed back the arm can be seen pushed fully out by the spring. The shape of the face of the arm and the notch are adjusted so the pin slides easily into place. Note how the lower lip of the traverser slides under the fixed deck helping to ensure accurate vertical alignment.

The entry track was trimmed and fixed in place lined up with the layout tracks, and also with the traverser tracks when they are aligned with the pin/notch (including both ends of the rotating traverser). A couple of the traverser tracks needed realignment with a soldering iron, but despite the less than ideal order of construction this seems to work well. The fiddle yard connects to the main board with an audio (RCA) lead, the other end of which connects into the choc-block connector under the board.

The extra depth of the rebuilt fiddle yard allowed the pivot bolt to be inserted with the nuts below (Awngate had a very shallow baseboard), this meant only the shallow mushroom head of the bolt protruded. This meant I could make the centre track a through road rather than having two dead-ends, both making it more useful and making the electricals easier, so a short length of track was cut to fit the gap between the existing PCB strips. However, the bolt head caused a hump in the track, and cutting away the sleepers meant the rails touched the bolt head. I carved away the lower part of the rail with the dremel so they sit neatly over the bolt head, and the red insulating tape should prevent any shorts. There seems to be adequate clearance for wheel flanges. 

An overview of the assembled fiddle yard. It can be seen how the two "handles"  lock the rotating upper deck to the traversing lower deck, they are unlocked when the handles are folded down to act as end-stops preventing stock runaways when rotating. Rotation is free and smooth, the latching seems to work well, and sliding the traverser forwards is smooth. However... when pushing the traverser back the latch is difficult to overcome and movement can start with a jolt, which is likely to derail trains.

I realised that the previous latching fiddle yards I have built were sector plates, the curvature of which allows the latching arm to be pivoted at a point in line with the track join, and so the arc of the movement of the arm is perpendicular to the movement of the pin - that is, the v-notch moves directly away from the pin and resistance is equal in either direction (see here). In this case the arms have had to be pivoted some way back from the track join, and despite making the arms as long as possible they must be at about 20 degrees to the line of travel of the traverser. Pulling the traverser forward the pin has an easy job to slide out of the v-notch, but when pushing the angle of movement of the arm effectively steepens the "slope" the pin has to push against to free itself. 

Hmm...