Towards pre-Grouping carriages in 4mm – the D508 appreciation thread

[billbedford]

I found the best for this job was the steel rail on the front of a Rayburn cooker, funny, but I haven't made many coaches since I left that house. 

[Jol Wilkinson]

I use a 3/4" diameter aluminium rod on some 3mm black underlay foam, increasing the pressure while rolling the rod to and fro until I get the correct curve. I have found that, as it Is a fairly gentle curve, it is quite easy to form.

 

It is important to make sure the rod and foam are clean, to avoid any unwanted dimples in the half etched sections of panelled coaches. Don't bother to ask how I know this.

[Compound2632]

18 minutes ago, Jol Wilkinson said:

I use a 3/4" diameter aluminium rod on some 3mm black underlay foam, increasing the pressure while rolling the rod to and fro until I get the correct curve. I have found that, as it Is a fairly gentle curve, it is quite easy to form.

 

That is equivalent in principle to what I'm doing but I feel there must be some combination of rod diameter, force applied to the rod, and Young's modulus and thickness of the underlying material*, that I'm not achieving by some margin with any of the combinations I've tried from time to time.

 

Too small a diameter, with too yielding a material, I've found results in a kink rather than a smooth curve. 

 

In this particular case, the beading on and adjacent to the doors is continued across the lower panels, which isn't the case on most panelled carriages; these give added stiffness resisting the curve one is trying to make.

 

*and patience...

Edited January 29 by Compound2632

[Jol Wilkinson]

1 hour ago, Compound2632 said:

 

That is equivalent in principle to what I'm doing but I feel there must be some combination of rod diameter, force applied to the rod, and Young's modulus and thickness of the underlying material*, that I'm not achieving by some margin with any of the combinations I've tried from time to time.

 

Too small a diameter, with too yielding a material, I've found results in a kink rather than a smooth curve. 

 

In this particular case, the beading on and adjacent to the doors is continued across the lower panels, which isn't the case on most panelled carriages; these give added stiffness resisting the curve one is trying to make.

 

*and patience...

 

The LNWR models I have built only have vertical beading on the lower panels on longer vehicles, something to do with the size of the timber sheets Woolverton could obtain. Even with those I didn't find forming the turn under difficult but it may be that if they are more closely spaced on your models it could be something of a problem.

 

The hardness of etched brass can also vary but I have never found that a problem with carriages, only with locos where it has occasionally been too soft. That may have been down to which etcher the kit producer used.

[billbedford]

2 hours ago, Compound2632 said:

That is equivalent in principle to what I'm doing but I feel there must be some combination of rod diameter, force applied to the rod, and Young's modulus and thickness of the underlying material*, that I'm not achieving by some margin with any of the combinations I've tried from time to time.

 

 

I think the rod should be fixed so that you can moderate the force applied to the brass. I would also burnish the brass down onto the rod with a piece of, preferably, hardwood. Multiple light strokes along the length of the brass are better than a few heavier ones. It is also worth fixing/holding a wooden batten over the upper part of the coach side so that you can control where the bending starts from. 

[Compound2632]

8 minutes ago, billbedford said:

I think the rod should be fixed so that you can moderate the force applied to the brass. I would also burnish the brass down onto the rod with a piece of, preferably, hardwood. Multiple light strokes along the length of the brass are better than a few heavier ones. It is also worth fixing/holding a wooden batten over the upper part of the coach side so that you can control where the bending starts from. 

 

This sounds similar to the technique using a piece of skirting board - the sort with a quarter-round section at one edge - which I have tried before. I think my problem with that was that the radius of the skirting board is very much less than that of the curve I was trying to put into the brass, so it was difficult to get a uniform, kink-free, curve.

[billbedford]

If I remember correctly the bar on a Rayburn is about 1 1/4 inch diameter. 

[Compound2632]

45 minutes ago, billbedford said:

If I remember correctly the bar on a Rayburn is about 1 1/4 inch diameter. 

 

The curve I'm aiming for is 8 ft radius, 32 mm or about 1¼" in customary units. The roller or former therefore wants to be no more than 2½" diameter but how much less is optimum? For the rolling method, probably also depends on the Young's modulus of the rolling mat. 

[Portchullin Tatty]

Stephen,

 

An amendment of your technique for forming tumblehomes to consider is to secure the lower edge of the carriage side to the rolling pin with masking tape so that as you roll it forward it pulls the lower edge up.  Otherwise, it is challenging to get the curve of the tumblehome to go all the way down to the bottom of the side.

 

 

Mark

Edited January 29 by Portchullin Tatty

[Compound2632]

I've taken a step back on the tumblehome / turnunder front and had a go at a simpler example - the 51L/Wizard kit for the D529 4-wheel passenger brake van. Here I found it much easier to roll the curve in; the parts don't have the stiffening ribs of the square-panelled carriages, it's possibly also not quite so hard a brass. The etched sides are possibly thinner, too. they're designed with an inner support side that is the full thickness of the brass sheet, but has half-etched lines to give a polygonal approximation to the curve:

 

 

The side top left is laid over the inner side, with the hinges bent through as location aids and the floor, roof, and end-tabs bent over. Top right is the other inner side, showing the inside face with the folding grooves.

 

The radius of curvature is checked using my 8 ft radius gauge / plasticard roof former:

 

 

The 2½" diameter Australian tawny dessert wine bottle which was pretty well the starting point of this topic! Thanks again to @richbrummitt. (A standard 3" wine bottle is near enough for 10 ft radius roofs for goods wagons etc.)

[Mikkel]

 

4 hours ago, Compound2632 said:

 

 

 

Trains in a bottle. Now there's a thought.

 

It looks like a lovely van. I see from the Wizard site that they were "the most numerous of all the Midland ‘all brakes’ ". Your usual fact-based approach, then.

 

[Compound2632]

1 hour ago, Mikkel said:

Your usual fact-based approach, then.

 

As we will discover, the kit only covers a fraction of them...

 

As it's the fifth Tuesday of the month, our club had a talk rather than the usual running or working night. One of our members has a large collection of Great Western carriages, 4 mm scale, built by himself or to commission, likewise mostly professionally painted - though in post-1927 liveries - and gave a talk on the subject, though I'm afraid after glancing at clerestories, it was all Dreadnoughts, Concertinas, Toplights &c. But what I did learn, that I had not been aware of before, was that G.J. Churchward was Swindon Carriage Works Manager from 1885 to 1895, having been for the three years before that assistant to the previous incumbent, James Holden.  So the implication is that he was largely responsible for "Dean" carriages, or more particularly, for the high degree of standardisation of components, (but not diagrams!) of those carriages. 

[Chas Levin]

18 hours ago, Compound2632 said:

The radius of curvature is checked using my 8 ft radius gauge / plasticard roof former:

 

 

The 2½" diameter Australian tawny dessert wine bottle which was pretty well the starting point of this topic! Thanks again to @richbrummitt. (A standard 3" wine bottle is near enough for 10 ft radius roofs for goods wagons etc.)

 

Hm; your main problem there I'd say is how to assure a ready supply of similar empty dessert wines bottles for the future... 🤔

[Chas Levin]

On 29/01/2024 at 16:10, Portchullin Tatty said:

Stephen,

 

An amendment of your technique for forming tumblehomes to consider is to secure the lower edge of the carriage side to the rolling pin with masking tape so that as you roll it forward it pulls the lower edge up.  Otherwise, it is challenging to get the curve of the tumblehome to go all the way down to the bottom of the side.

 

 

Mark

 

Hello Mark and Stephen, I'm about to undertake some turnunder rolling myself and read of an interesting technique over on Western Thunder, where using two pieces of thinner material (either very thin brass or thin cardboard) to sandwich the edge of the side and continue out well past that edge allows the bend to be maintained up to the workpiece's own edge. This was being done using rolling bars but could equally well work in other scenarios. I thought it a very useful idea and plan to test it for myself...

[Compound2632]

17 minutes ago, Chas Levin said:

Hello Mark and Stephen, I'm about to undertake some turnunder rolling myself and read of an interesting technique over on Western Thunder, where using two pieces of thinner material (either very thin brass or thin cardboard) to sandwich the edge of the side and continue out well past that edge allows the bend to be maintained up to the workpiece's own edge. This was being done using rolling bars but could equally well work in other scenarios. I thought it a very useful idea and plan to test it for myself...

 

Interesting. I had been wondering something like that, noting that most of the etched side is not in contact with the pad or whatever upon which one is doing the rolling.

 

22 minutes ago, Chas Levin said:

Hm; your main problem there I'd say is how to assure a ready supply of similar empty dessert wines bottles for the future... 🤔

 

I'm hoping the bottle will remain a useful tool for years to come. Otherwise I'm at the mercy of @richbrummitt's drinking habits. (For shorter roofs / sides, I also have a Tesco olive jar of the same diameter.)  

[Citadel]

I was definitely a bit spoiled in my first year of carriage building in that the LRM kits I was making  had a full length and full thickness strip that is eventually folded at 90 deg to the finished side to sit flush on the top of the underframe.  This holds the edge nice and straight / rigid and means that when you are forming the turnunder (in my case by applying pressure with the bar onto a flexible surface) there is upwards force on the brass etch both above and below  the area taking the curve.  Agree that forming a nice turnunder right up to the edge of the brass is difficult and @Chas Levin’s suggestion to sandwich between thin brass or card protruding beyond the edge is a good one - will defnately try this.

 

I do tend to use a bar of smaller diameter than the desired curve and use it a bit like a rolling pin applying relatively gentle pressure to gradually form the turnunder and prevent creases.  Where the lower part of the carriage side is fully half etched like the one above this is a doddle, when there is a wide full thickness section I do struggle a bit - this is where satin paint on the finished model hides a multitude of sins.

 

Anyway, really interested to hear how you get on.

[richbrummitt]

9 hours ago, Compound2632 said:

I'm hoping the bottle will remain a useful tool for years to come. Otherwise I'm at the mercy of @richbrummitt's drinking habits.

It should last a long time. I drink less than I did and I don’t go near to your house on a daily basis. There are however three more in various states of emptiness (this vigneron does all her desert wine in the same size and style bottle) so more are available we would just need to arrange a delivery/collection. 
 

 

Edited January 31 by richbrummitt
words

[Compound2632]

I've assembled the sides for the 51L/Wizard (ex-PC Models) D529 passenger brake van:

 

 

Soldering the door ventilator hoods straight was a bit of a game. The curved tops and bottoms of the duckets were formed round a 2.3 mm-diameter drill shaft. the top curve is in the full thickness of the brass and was hammered* to shape with the straight section of the ducket held in the bending bars, which do double duty as a vice.** The bottom curve is in half-etched material so was easier to curve round the shaft by finger pressure.

 

*Not with a hammer. An engineer's square has many uses and abuses, and also nice flat surfaces.

 

**I do have one of those multi-angle pin vices but all the various tables or desks I use for modelling have a bar or rib under the edge of the table-top, so I can't clamp it to the table.

 

As to the Branchlines six-wheeler sides, I've had an idea...

[Mol_PMB]

That looks a lot like the second MSC Cashier's coach:

It was purchased by the MSC in 1953 from The Central Wagon Company, and arrived bearing the number M198718. I assume that there had been an intermediate stage in its life, perhaps in BR departmental service, and this might have been when the end doors were fitted. I believe it still exists in preservation.

Sadly there's no 7mm scale equivalent of the etched kit you're building.

 

[billbedford]

24 minutes ago, Mol_PMB said:

Sadly there's no 7mm scale equivalent of the etched kit you're building.

 

 

A 7mm etching might be possible if you really, really wanted. one. 

[Compound2632]

34 minutes ago, Mol_PMB said:

That looks a lot like the second MSC Cashier's coach:

 

Yes, that's certainly one. It's one of the later ones, with 8 ft radius roof, like this kit.

[Mol_PMB]

35 minutes ago, billbedford said:

 

A 7mm etching might be possible if you really, really wanted. one. 

That's an interesting thought. Does the etch artwork already exist for for a 7mm scale version?

 

I would like to build one of these eventually but I have a lot of other projects on the go at present. I had planned to create my own artwork for a one-off etch, and if I did that I'd include the various modifications made by the MSC. But the modifications wouldn't be too hard to achieve based on an etch of the standard D529 if that could be produced fairly easily (well, more easily than me drawing it all up!).

 

I have a secondhand Mercian D505 kit which I hoped would provide some of the other components needed, though to be honest I don't know how much there is in common between D505 and D529. There may be a can of worms lurking here... I used to have a copy of the Midland Carriages book but (a) I lent it to someone and it never came back and (b) I recall there wasn't much detail on the 4-wheelers.

 

Thanks,

Mol

[Mol_PMB]

I've just found some more history of the MSC vehicle here:

https://chasewaterstuff.wordpress.com/tag/mr-4-wheel-passenger-brake/

[billbedford]

2 hours ago, Mol_PMB said:

That's an interesting thought. Does the etch artwork already exist for for a 7mm scale version?

 

 

Different scales are produced from the same artwork by using the appropriate thickness of metal. 

 

There is a 7mm tool for the D.529 PBV, but I haven't etched from it for 10 years so I don't know what state it's in. 

[Compound2632]

2 hours ago, Mol_PMB said:

I've just found some more history of the MSC vehicle here:

https://chasewaterstuff.wordpress.com/tag/mr-4-wheel-passenger-brake/

 

With 8 ft radius roof, it is from lot 96 of July 1883 onwards. 100 were built to lot 96, 30 to lot 140 of November 1885 and 9 to lot 165 of January 1887, all as renewals of old Kirtley vans; if 68 is the original number, it is likely to be from one of these lots. [R.E. Lacy & G. Dow, Midland Railway Carriages, p. 367.]