7mm On Heather's Workbench - another Broad Gauge journey

[Heather Kay]

Last year, as old hands will recall, I was commissioned to build some 7mm scale broad gauge coaches. The first pair were handed to the client earlier this year, and now it is time to begin a third coach.

It's another Dean 6-wheeler low arc roof specimen, to be portrayed in its final years of service. To be correct, it is a diagram U20 1st/2nd Composite Luggage, a broad gauge body on a broad gauge underframe. I have the kit here, a former IKB Models etched kit - for the narrow gauge version, of course.

As usual, there are replacement ends for the 10ft wide body from the Broad Gauge Society. The basic specs are exactly as the earlier S6 All Third build, but with the wider body. I'll have to find some interior details and make the roof. Oh, and I also have to split the underframe down the centre to widen it.

I did that, and then realised that while the underframe is the correct wheelbase, it's also short by a couple of feet. Oh, here we go, I thought.



Bear with me. Here you see one side of the coach, still in the flat without any turnunder formed. The centre compartment is for luggage, flanked by first and second class compartments. Half the split underframe sits on top, where you can see its short - 1ft 6in at each, to be exact. Having learned from my mistakes with the S6, I boxed clever and left the headstocks in place this time. Fat lot of good it will do me!

Now, the wheelbase is correct: 9ft 6in + 9ft 6in. This means I only need to add length at each end. The solebars will have to stretched somehow. There's a lovely half-etch overlay solebar with all the rivet detail, but I think I'll struggle to hide the join as I graft new bits on the ends. I think this means I shall have to fabricate a new overlay, with sufficient strength to hold the headstocks in place.

It was some way before I reached this point in the process I had seriously questioned my sanity.

Did I forget to mention I will also need to make new footboards as well?

That's another chunk of kit etch thrown in the Bits Box.

I've spread all the parts out on my bench, and I keep staring at them hoping some inspiration will strike. It's not looking hopeful today.

 

[S7BcSR]

Where have you managed to get a drawing from, the BGS?

Rob

 

[Heather Kay]

Hi Rob.

I don't have a drawing - yet. I will be getting a pack of the data sheets for passenger stock, which has a basic dimensioned sketch and some other data on it.

Modelling this period - the late Victorian - throws up all kinds of unknowns. I take the view that if those with deeper intersts haven't found it out, I can get away with a certain amount of educated guesswork. I like to think my client will be happy with something that looks about right, rather than expecting to get an inch-perfect replica of a real vehicle.

 

[Heather Kay]

While I continue to mull underframe options - currently thinking I'll scratch build the solebars from suitable section - I set about the bodywork.

After a gentle annealing, the sides and ends were rolled using the tape-and-roller method. Very successful, so thanks to @Rob Pulham for pointing me at that technique. the bolection mouldings were zapped in with the RSU, and I've just finished one side of the door droplights.

Although I plan another build tomorrow, I might spend a while in the morning just finishing off the droplights on the remaining side.

I am reasonably pleased with the progress today.

 

[Heather Kay]

Mild progress on this build today. Sometimes I find if I set my targets low I tend to achieve more. Today, fitting the door bumpers and latch plates. If I'm feeling lucky, I'll also fit the hinges.



The bumpers are nothing more than 0.7mm wire pushed through holes and soldered. The trick is to set the depth for them on the outside. This is supposed to be set by the bolection mouldings, but it didn't seem deep enough this time. I put some scrap etch underneath so a bit more protruded.

Once soldered in, the backs were trimmed flush. Using the scrap etch as a fence, I ran a file over the fronts so they're all the same depth.



The door latch plates are all done. The holes will be drilled through for the T-handles. I'll also clear through the commode handle holes.

 

[Heather Kay]

While the parts were on the bench, I fitted the hinges. As with the previous builds, the etched slots for the hinges are over size. I'm going to have a think about how to satisfactorily fill the gaps, or whether to just ignore them as last time!



The end steps fitted. They do look a bit wonky in places - I forgot the instructions advise to score a fold line, and had cut them out and cleaned them up before I remembered. Once painted they won't be so obvious. I've added handrail bracket bases from scrap etch. These will be drilled out for the wire handrails, hopefully before I assemble the ends to the sides. Let's hope this detail doesn't fall off while solder operations take place...

 

[Rob Pulham]

hopefully before I assemble the ends to the sides. Let's hope this detail doesn't fall off while solder operations take place...

Hi Heather,
You need to get some aluminium hair grips from Eileens - they are great for acting as heat sinks so that steps etc. don't fall off while adding other bits - worst case you can always cover them in blobs of wet tissue.

 

[Ian G]

Try maplins for heatshrinks and some better electrial traders at shows, I have some at home and these are good for fiddley areas.

Ian G

 

[Heather Kay]

Thanks Rob and Ian.

A "d'oh" moment. I've got about a dozen such grips on the bench!

 

[Heather Kay]

Another step forward on this build.



The sides and ends have been assembled. I used Carr's 145 and a little swearing. A little fettling will be needed at the joints, but it isn't too bad. From experience of the previous builds, I will fit some cross bracing for extra rigidity during the build process. I shall also work out the internal partitions and floor, possibly consider the roof, and continue to ponder how to stretch and widen the underframe.

 

[Wagonman]

At least the roof on this one is only a single arc

 

[Heather Kay]

I know. I'm dreading the likelihood of the client wanting the other sort!

That said, he gave me an etch for an 8-wheeler he plans to have built. It's a clerestory, but has been designed quite well.

EDIT to finish my thoughts, as I just had a phone call…

The roof has been designed as an arc, over the full width, with the clerestory and its roof built on top. There are slots where the clerestory lights let light into the body. The designer had obviously thought it through well enough.

 

[Heather Kay]

I have to tackle the underframe. It's today's frog that must be consumed.



First, though, here is the bracing. Scrap etch has been fitted across the floor rebate, and at strategic points along the top edge. I spent a short while considering the best locations for the top strips, opting eventually for just inboard of the compartment divider. Being a composite luggage coach, the outer compartments are 2nd class, the inner ones 1st, and the centre is for luggage. Floor and dividers, as with the S6 build, will be styrene sheet. The bracing is also useful as a method of handling the shell during painting, so that's a plus.



Time to tackle the underframe. As well as the longitudinal split, I have to encompass a stretch of about four feet. Luckily, if you recall, the wheelbase is unchanged from the 19ft frame I've been supplied with. I have been considering various methods of extending the frames and floor. You might be able to make out the half-etched marks for the 19ft headstocks, and also that I have purposely left fret at the ends of the underframe parts.

The issue I have is how to convincingly extend the half-etch overlay. In order to help my brain consider the options, I decided to fit the split floor to the solebar and axleguard parts, which also helped to flatten a slight banana tendency in the floor. I have also added some scrap etch to strengthen the bases of the brake hangers - something learned from the previous build of this type. I also fitted the axleguard tie bars while everything was in the flat. So often I have forgotten these parts until later in the build. This time I have got them in early!

So, solebar overlays. The kit parts are designed to fold back to meet with the headstock. This feature I am unable to repurpose, as the overlays are left with extended ends. My original plan was to replicate the overlays using brass strip, but I haven't managed to source thin enough material of the correct size. I am not in the mood for trimming strip accurately along its length. My current thinking is to use the kit parts and hope the slightly odd ends don't notice once the foot boards and brackets are in place.

As for the headstocks, I have some suitable brass channel which will give some needed strength to the ends of the underframe. I hope I can drill things accurately, which seems to be something I have problems with!

 

[Heather Kay]

This being the third BG model I've tackled, it is not for the first time during the stretching process that I've wondered why no-one has come up with a better way. Perhaps they have, and I've not noticed it yet.



I have realised I've fitted the solebar with the vee hanger to the wrong half of the floor, but it doesn't really make that much difference to this build. After some CAD (cardboard aided design) I was happy with the spacing between the halves, and set to with scrap etch to hold them at that distance.

Again, perhaps I'm missing something, but where do I find fundamental dimensions for BG stock? How wide should things be across the frames? How far apart were the buffers? Everything I've done has been interpolated from body widths, assumptions made after instructions say to insert a "17mm wide strip for 7mm", and - gasp! - literally measuring from drawings reproduced at a nominal 4mm scale. From all that I've assumed the over-frames width to be either 9ft 6in or 9ft 9in, the buffers at 6ft centres, and the headstocks to match the width of the body that sits on top.

Has someone come up with a better way to do this?



Anyway, back to the fray. To help the floor remain flat and stuck to the extended side frames I have soldered in some brass angle. It needs trimming to be neat, but I've tried to be more methodical about where such bracing and extensions go with this build. The headstocks will be fitted to this, somehow.

This is part of the fun of this build, the fact that some things only make sense once you actually start to put them together. It's a kind of free form modelling which seems wrong, but which can be fun when it works out.

 

[Heather Kay]

I had a bit of a rethink. This happens usually after I've done a bunch of stuff, so I have to undo it all again to do it properly.



I neglected to mention that part of yesterday's works included making new footboards from some milled brass angle of just the perfect size. The offcuts from that exercise led me to thinking about how to ensure the brassmongery for the headstocks was of equal length on each side. Serendipitously the footboard angle is a close fit to inside the channel I will use for the headstocks, so off came the brass angle from this morning to make way.

I calculated the headstocks should be 28mm from the outer edge of each axleguard. By trimming the L-section to 28mm, and then fitting it inside the end of the solebar - it being almost exactly the correct depth to match - I could reinforce the solebars and floor as before, but also give me something to which to fit the headstocks later. I aligned it using the axleguard for reference.

I love it when a plan comes together.

There still need to be plates for bolts to attach the body, but the thinner web of the L-section takes up less space in the area. I think I shall clean up my work, then stop while I am ahead!

 

[Heather Kay]

Things were going well, so I carried on and made up the headstocks and fitted them.



I managed to drill holes more or less in the right places, and fitted the kit overlay for the draw gear slot. Sadly, the nice overlays for the buffers would end up in the wrong place, so the headstock steps will have to be from CPL etches. The buffers, as with previous builds, are Slater's MR wagon buffers.



I don't like butt joints, but the main work is being done by the solebar angle in the channel.



The hole for the draw hook was drilled 2.3mm, and to avoid too much flapping about I used another one of the kit etch parts on the back of the headstock.

I'm quite pleased with the way it all turned out, and pleased it was worth pressing on with it.

 

[OzzyO]

Hello Heather,

a nice looking build, but one question, in post 5 you fitted the door latch plates. But how will the doors open as it appears that the latch plates are fastened to both the door and the body!

OzzyO.

 

[Heather Kay]

It does look that way, doesn't it!

When I fitted these parts on previous builds, I spent a while studying contemporary photos to make sure I wasn't going mad. The plates do indeed sit over the door gap, but in real life split at that point. I think the issue is being half-etched already there's no way to represent the split between the door and the body. I could, I suppose, score a line but these things are already tiny and, frankly, you'd never see it and it would fill with primer and paint.

From the usual viewing distances it matches the prototype photos quite well.

 

[Heather Kay]

Yesterday was an out-and-about day, so nothing got done at the workbench. Today, I've been fettling and fitting odds and ends, while I ponder the next phase.

I thought it might be prudent to fit the couplings at this point. Older readers may recall previous builds had the coupling hooks connected in the centre of the coach to help spread the load.



We have settled on Slater's working screw links for this series of models, so that kept me occupied for a while trying the thread the trunnions on!



The inner vee hanger has also been installed, so the next stage will be to fit the suspension and axle boxes. I've added plates to the corners of the body shell for fixing bolts eventually.

I think this afternoon will be spent on another project. I'm about fed up with this coach for a bit.

 

[Heather Kay]

With other builds having reached a sort of stasis I've brought this build back off the shelf.



The act of stretching the underframe meant the nice half-etched overlays no longer fitted. After some abortive attempts at repurposing the kit parts, I decided that a scratch build was the way forward. Happily, Mr Beare of this parish had some stocks of brass shim of around 10 thou, so a suitable strip was acquired.

At first, I was going to mark out the bolt/rivet positions manually. I soon realised my marking out skills would mean this would be a disaster. Time for some CAD.



An hour or so later on the pooter I had produced a paper template with the rivets marked out. A squirt of Spraymount and some time with the riveter produced reasonable overlays. At some point during the marking out and punching out works, though, things had moved a tiny bit. While the pattern of heads fitted neatly over each axleguard, the distance between each set of patterns had shrunk a tiny amount.

I realised I could split each overlay at the point where the footstep brackets go, which meant I could realign the axleguards and their bolt heads.



So, the state of play so far has seen me cleaning up the work from yesterday, adding reinforcing plates on the top corners of the underframe, beginning to contemplate the whole internal springing unit thing, and considering how to attached the body to the underframe at a later date.