7mm On Heather's Workbench - wider and longer

[Heather Kay]

The brass strip order arrived next day, which was impressive. Nice one Eileen's Emporium!

The lesson for today is if you intend to bend 0.5mm brass strip to 90 degrees you should anneal it. Obvious, really. Anyway, all the hinges were sorted out on the new bodies pretty quickly, I cleaned up the door bumpers, and was on such a roll I assembled the sides, ends and compartment dividers.

Just so we know, and in case I forget, the longer coaches here - 46ft 6in diagram E3s - were built in three lots, some ten years apart. The plan is to build one to the earlier 1876 lot, and one to the later lot. The chief differences are in the underframes, which I hope will become apparent eventually.

 

[Heather Kay]

I couldn't put the day off any longer. It was time to relearn how to use a lathe.



This one, to be precise. It's been lurking in our large shed for years, just biding its time. The first job was to clean it, as whoever had used it last - hard stare at Best Beloved - hadn't bothered to clean up the swarf and excess cutting fluid. To be fair, that was probably not a bad thing. Although the shed is quite dry, there was evidence of some surface corrosion, and where things had been left mucky had helped prevent it. Anyway, the photo is the result of a good brush down, vacuum cleaning, and a gentle buff with some 3-in-1 and wire wool.



Earlier I had chopped up 5mm brass hexagonal bar to roughly 45mm lengths. I even treated the junior hacksaw to a new blade for the job! What is this all in aid of, and what has it to do with broad gauge coaches? You may well ask.

I may have alluded to building these four eight-wheeled rigid underframes as pseudo bogie coaches. The BGS provide an underframe kit, which is intended to let you build a sort of compensated radial truck affair. Learning from the experience of others, and on recommendation of Alan Garner, former chairman of the BGS and long-time model railway acquaintance, I decided to build proper hidden bogies designed as inner frames. The idea was used by Alan, based on a design by Trevor Hughes which appeared in MRJ 78. Alan's write-up was published in the BGS journal No 69, Spring 2013, and it his dimensions and materials I am following.

So, the hex bar is for the bogie pivot and centre spacer. The job for the lathe was to clean up and square up each end, skim the bar to 44.5mm long, or as near as my usual measurement skills can manage, pop a centre mark on each end and drill a little way in with a 1 or 1.2mm drill. I won't go into the bogie design details yet, as I hope it will become clear in due course.



Here we are, ready to square up an end. Ideally, there would be less of the work sticking out. I have the wrong chuck in the machine, which previously has been used for reprofiling wheels, using the tail stock and various bits and bobs. This chuck won't let the work poke all the way through, and for some reason my tutor today, Best Beloved, felt it was too much effort to fit the proper one. Let's just say we got away with it, and have agreed to install the other chuck for future work!

The first stage was to square up one end of each of the bars. I ought to sort out numbers for you: four coaches, two bogies each, that's two bars per coach, eight bars in total. I cut two off two spare lengths to allow for the inevitable visit from Captain Cockup.



Once I had been through and trimmed one end of each bar, we set up the tail stock to centre pop them.



Next, I applied marker pen to the untrimmed ends. You can see the only breakage I had today - my thumbnail!



Setting the digital vernier calipers to 44.7mm - I know I wanted 44.5, but I don't think 0.2mm will make all that much difference - I did the naughty thing and used the sharp bits to scribe the length I needed to trim to all round the bar.



Then I was ready to begin again. It took a while to get my eye in, but eventually all the bars were trimmed to near enough the correct length. Once squared up, the ends were centre popped, then it was time to drill.



Swapping the tail stock for the one with the drill chuck, a 1.2mm drill was used to make a hole in each end about 2mm deep.



And there we are. Time to clean the lathe, ready for another time. I only lost one bar to error, which justified making a pair of spares at the start!

My next job is to work out how to mark up, cut out and drill a dozen identical side sheets from NS sheet…

 

[simond]

Heather,

If you face off both ends reasonably flat, and then measure each bar accurately, you will know how much too long each blank is. Chuck each blank in turn, run the tool up to the end if the bar, until it just touches, pull it out on the cross slide, move it along the required amount, and then face to length using the cross slide.

Or, of course, cut them off using a parting tool, in similar fashion, measuring the length using the main feed. Don't forget to allow for the width of the tip of the tool if doing it this way.

Apologies if this is obvious...

Best
Simon

 

[Heather Kay]

Apologies if this is obvious...

No apologies needed. It's not obvious to this lathe work tyro! It sounds an eminently useful idea, and would be ideal with the correct chuck installed. Filed for future eight-wheelers!

 

[JimG]

Heather,

Or if the "wrong" chuck is presenting a stop for material, cut you bars roughly to length with one of their ends finish faced. Then insert the first one to be cut to length in the chuck, hard up against the stop in the chuck, and machine to length and note the cross-slide settings on the finishing cut to length. Then insert all the other pieces hard up to the stop in the chuck and turn down to the cross-slide settings already noted. In my case I would try to do this with the topslide doing the moving and with the saddle locked off. You just have to make sure that you don't get any stray swarf on the stopping part of the chuck and the ends of the parts.

Jim.

 

[Heather Kay]

Well, I thought I had a plan for marking up and cutting out side frames for the pseudo-bogies. The plan would probably have worked, and if I were only building one coach it might have been practical.

Four coaches, though, that's another prospect. From my previous, you can tell how good I am with figures, because it's not a dozen sides, but 16! I made a start on the first frames this morning, and hit trouble straight away. My piercing saw limits the depth of cut I can make in the sheet material, and then the second frame I cut out wasn't even quite the same shape or size as the first - and that's before I'd got round to the complication of cutting the shape from the blank...

I regrouped, and decided it was quicker and cheaper to arrange a drawing and get it etched. So, that's what I've done. The artwork has just been pinged off to the etchers for approval. I suppose I'd better get on with something else while I wait for the sheet to side frames to come back!

 

[Heather Kay]

PPD did a splendid job, and the sheet of side frames was waiting for me when I got home from Telford.



I had expected nickel silver, but I got 28 thou brass. It doesn't really matter.



The cusps need filing down, thought it's not critical. The only critical ones are those in the axle holes, which I dealt with using a taper broach. The three dimples have to be drilled out, the centre one I used 1.2mm to match the pivot wire I am using, the other two 0.8mm for the torsion bar wires.



Raw materials for one bogie. The wheelsets are by Slater's, provided by the BGS. For this build, I need to cut off the pinpoint axle ends. I file a round edge to the end of the axles after chopping them, so it's a bit easier to push the wheels on.



In less time than it took me to mark up and cut out one blank in the earlier plan, one completed bogie. Before long…



… I had a pair. You can sort of see how the torsion system works, with the frames pivoting around the central crossbar. The wires force the frames back to level. I've worked out some refinements to the basic design, one of which would be to move the torsion wires a little further away from the pivot. The design here does work, and I don't think a wider spacing will make that much difference mechanically, but it may help with construction.

I have now prepped the remaining sides for the other three coaches, assembled the pivot bars, and begun chopping the axles. With a fair wind, I could have all the pseudo-bogies built tomorrow, and I can begin to think about assembling underframes.

 

[Yorkshire Dave]

A nice and simple equalized truck.

 

[Heather Kay]

It's been one of those weeks, domestically speaking. Little progress has been made on this build, aside from all the required "bogies" being assembled. With the running gear finished, it was time to tackle an underframe. As is usually my preference, when building several of something, I like to build one more or less all the way through so I can learn how it all goes together.



This is where I started. This is a sort of universal 8-wheeled underframe kit. In its raw form it fits the longer coaches, though as you can see the only items actually long enough are the side frames, associated overlays and the steps. You can also see the compensated bogie system, which is being ignored for this build. Lots of other details are also included to give brake gear, various body details and so on, much of which will be consigned to the scrap or Bits Box.

I read the instructions, scratched my head, read the instructions again, took a magnifier to the exploded diagram, and finally managed to figure out which bits I needed to make a start.

First up, the side frames needed some folding. Then it becomes obvious three other parts form the cross members and much of the floor of the coach. Eventually it dawned on me that the slots left by folding the sides fitted the cross members in one way only, so I set to with the soldering iron.

After some faffing about, I managed to get things together reasonably square and flat.



This is upside down. I've left the commode handles in place in the etch because they're not wanted for this build and I couldn't be bothered cutting them out!

Okay, I now have a clearer idea of how the underframe kits work. Having got this basic carcass, to which I still need to add the frame overlays, it think it's probably sensible to consider how the thing attaches to the body of the coach. Right now, there are no obvious fixing points.

I find this a lot with these forays into the world of broad gauge Swindon. I am reliant on other modellers' work for inspiration, a sketch diagram from a data sheet, and educated guesswork. The original kit design allows for brake gear to be fitted to the "bogies". Obviously, I'm going to have to concoct a different attachment system. How do the truss rods fit, and where is the queen post the instructions refer to? How many axles were actually braked? (it would seem only the inner pair, although these vehicles do appear to have a hand brake in the luggage compartment.) It would also appear Mr Dean was fully expecting things to come apart at such a great length of underframe, as there are tie-bars everywhere! Oh, and let's not forget some wiper pickups for possible future coach lighting…

Tomorrow, then, I shall get the RSU in play for the various overlays, then work out the W-irons and associated gubbins. The mist may lift on other parts of the construction soon after!

 

[Scale7JB]

Hi Heather, I like the idea for the compensated bogies.

Just a thought with regard to longevity. Is it worth soldering some thick walled tube, or bored brass stock to the insides of the side frames? I understand that it can't be too thick as that will prevent movement, but adding a little extra will prevent ovaling of the holes over time, especially if the client doesn't oil the bearing surfaces very regularly..

JB.

 

[Heather Kay]

Just a thought with regard to longevity. Is it worth soldering some thick walled tube, or bored brass stock to the insides of the side frames? I understand that it can't be too thick as that will prevent movement, but adding a little extra will prevent ovaling of the holes over time, especially if the client doesn't oil the bearing surfaces very regularly..

Good point. It might be worth considering allowing for a proper bearing to fit the axle hole for future designs. I shall take that under consideration for the final variant that may end up with the BGS.

As it is, I'm not sure how much running the models will be required to do in their final home. I shall impress on the client the need for regular lubrication, though.

 

[Heather Kay]

It's at times like this I wonder just what the heck I was thinking when I took on these builds!

Incidentally, I make no apology for the messy soldering. I have sat the No Solder Guild exam several times, and have come up short so far. This "kit" isn't helping.

I left the build with a sort of square-ish main frame, with the idea of fitting the half-etch solebar overlays. From there, it was but a short step to fitting the W-irons.



I couldn't really help myself. It had to be done. Sadly, there's still a whole load of engineering to come before I can contemplate a rolling chassis. A prime example is the need to make up some kind of bogie bolster to fill the space between the "floor" and the bogie so the ride height is about correct. Anyway, there's the first 8-wheeler, beginning to take on the somewhat ungainly elegance of the broad gauge rigid eights.



Inside, you can see I have my work cut out finding a way to fix the body to the underframe, and filling the holes in the floor.



With W-irons fitted, it was time to work out the suspension. Here you see the raw materials. I have some serious fettling to do, as you can see. These castings are pretty ropey, and all will need drilling to accept the dropper from spring to support iron. The underframe kit provides some etched parts for rivet plates and axleboxes, but I'd still need to make up the J-hangers, so making something out of this lot is where I'm heading. I only have another three of these underframes to go…



Posed, wonkily, on the frames. I mentioned lots of tie bars before. There's a huge plate bar between the W-irons, smaller bars keeping the axleboxes in place, and then there's about a mile-and-a-half of wire ties between everything! The GWR did not want anything moving about. On top of all that, there are the step boards and associated hangers - I think I've overestimated how many hangers I need, because the kit implies about three per side, while the drawings imply four. No photo references to fall back on, so I shall have to think on.

There is, still, the question of braking. I think there are shoes that bear on each corner of each pair of axles. The instructions imply this, the diagram sketch doesn't help. More thinking, as I need to engineer a fixing for the brake gear eventually.

Like I say, I wonder why I take this stuff on!

 

[Scale7JB]

I think you would save yourself a whole heap of trouble remaking those J hangers out of brass rod and bar with some nice brass nuts, and they would be so much stronger..?

JB.

 

[Heather Kay]

I think you would save yourself a whole heap of trouble remaking those J hangers out of brass rod and bar with some nice brass nuts, and they would be so much stronger..?

JB.

Twelve per coach… it would be quicker to make a new master and have castings made.

I've sort of formulated an idea on how to construct things off the underframe at first, so the springs and hangers can be fitted as a complete assembly. Before I plunge in and top up my lead content, though, I shall dig around and see if I can find better parts.

It gets better. I checked some references, and I should be making loop swing links between the hanger and leaf spring. Eep.

 

[Scale7JB]

I guess it depends if the client wants an out of the box build or a 100% correct masterpiece...?

JB.

 

[Heather Kay]

It's been a while, but I've made some progress on this build. The state of play was one more or less completed underframe and pondering on the various castings to fit thereon. Pondering has led me to think another session of artwork and etching might let me create suitable plates upon which I can assemble the cast springs and so on. The whole thing can then be "plugged" into the underframe as a complete unit.

Before I get into that, though, I decided it would be sensible to build up the three other underframes. The remaining long coach went together reasonably, after some epithets were aimed in its general direction. Time, then, to consider how to shorten the 45ft underframe kit to suit the 40ft bodies. Apparently, it's easy to do.



The basic assembly is as before. Three floor plates sort of slot into side frames that are part folded to represent the top of the solebar channel. Headstocks are soldered across the ends, half-etch overlays on the solebars, and Robert is your mother's special friend while your dad's away. The question was how to shorten things to lose a scale five feet. With reference to the BGS diagram sheets, I worked out the wheelbase and whereabouts the V-hangers were situated according to the body. Then I remembered the shorter body kits included replacement solebar overlays. That would be a help in sorting out final lengths, anyway.



Now it began to make some sense. Obviously, details like holes for aligning axleguards and step brackets would have to go by the board. With luck, it should be possible to reuse the side frame slots. Here we see things laid out by the body.



With the notion of fitting the V-hanger floor plate in its orthodox position regarding the side frames, it became a case of shifting the end floor plates inwards. Rather than slice off chunks of the side frame, I realised I could slot the floor plates to fit around things instead. The lower plate is as it came out of the fret, while the one above has seen some piercing saw, skrawker and filing action. The skrawker came into action to help create a half etch line for the side frame to locate in. That would be a useful amendment to the kit artwork in any case.



And there we are. A 40ft underframe in embryonic form. The second has had the surgery and is waiting to be assembled as I type. I do need to measure up and locate the axleguards, and then there still remains the question of solebar overlays and potential additions for the suspension fixings. Still, it's progress.

 

[Heather Kay]

I had a pretty good start to the week, managing to fit the solebar overlays and W-irons to all the underframes.



Next I wrestled 32 W-iron tiebars from the fret, trimmed them and pressed out rivets.



While my sanity teetered on the precipice, I cleaned up 16 of the large tiebars (which tie the W-irons together just in case - did I mention Mr Dean really didn't want anything moving about downstairs on these large rigid underframes?). These bits need to be bent, reliably, uniformly and accurately, to fit the model. I'm still working out a way to achieve that.

The small ties have been soldered in place. Oddly, I found it was the fifth one on every coach that would give me grief, slipping just as I lifted my toe from the RSU foot switch. My plan is to form the large ties and get them fitted to all the frames. By then, with luck, my brain cell will have worked out a way forward with the suspension parts.

 

[Heather Kay]

I had visions of jigs and formers to help me reliably shape the large tiebars - which I think are probably representing compensation beams on the real thing. In the end, a simple mark 10mm and 12mm in from each end let me form the reverse bends quickly with nothing more than my Maun parallel pliers.



And in short order, four underframes were decked out with another set of components.



I think the rod ties next, which I plan to assemble in several parts. It would seem more sensible to form up the rods in one piece, but I think it's probably safer to do in sections to allow for the subtle variance in each underframe. The variance is down to me, not just the way the underframe kit was designed.



I wonder if I should stop now. Everything has, so far, been going well. I suspect an inevitable howler is lurking somewhere in my future!

 

[Heather Kay]

I'm calling it a day. I have fitted out one side of an E3 (the longer coaches) with the wire tie rods.



The idea of splitting the tie into sections worked - aided by the fact I don't have 0.7mm brass wire in such lengths. As it turns out, the distance between the outer W-irons is just a smidge shorter than Eileen's Emporium's standard 250mm lengths. This meant the outer angled ties could be made up separately.



The end ties were fashioned to shape, all four corners at the same time for consistency's sake. I carefully soldered one end to the back of the W-iron, with strategically placed Dinkie clips to prevent the front tiebars from dropping off. I drilled holes in the corners through the "floor" plate, with the intention of spot soldering the wire from above. In the end, I dabbed some solder into the corner with plenty of flux and a hot iron.

It'll do. I'll finish the rest of the coaches tomorrow.

 

[Heather Kay]

I was making some good progress yesterday, then I came over all queer. Shivers and shakes hit after lunch, so I went to bed and ended up sleeping for about four hours. Another eight or nine hours have followed, and despite feeling a bit light-headed, I think I'm up for some breakfast.

Where did I get to? Ah, yes, finishing some tie rods.



I find these builds alternately interesting and frustrating. There's precious little prototype information available, so a lot of details tend to be guessed or worked backwards from later coaches. The instructions cheerily suggest fitting the queen post and attaching it to the wire rod. Not a problem, save there's nothing identifiable as a queen post on the detail etch.

So, I wondered, might I be lucky and locate a photo that would elucidate? Well, as it happens, yes. A broadside works photo of an eight-wheeler is in the Russell books. It's just large enough to make out the queen post appeared to be wrought iron rod, like the tie rods. Quite how it was fixed to the rods remains to be learned, but I'm happy to work on the notion that a dab of solder will be hidden by the full-length step boards anyway!

Like much of these underframe kits, the artwork was generated before CAD. The various apertures for pushing out rivets and holes in the solebar tend to be somewhat over size. The central queen post hole is no exception, weighing in at about twice the diameter needed for the wire. Still, it made it easier to finagle the queen post wire after I'd shaped it to sit neatly. I started out with wire overlong, made various bends at one end so part of the wire would sit flat inside the solebar, and tweaked it so it would meet the longitudinal tie rod. Rough and ready, but adequate.

I wonder if I'll be up to finishing the rest of the underframe tie rods today?