The cab roof is another job that's been continuously pushed down the to-do list in favour of easier stuff. Can't put it off any longer I'm afraid, and it did turn out to be a bit of a performance. I wanted the roof to be removable to make assembly of the cab interior detail and painting of the cab easier. The design intent of the kit is to solder the roof to the cab front and sides, so some modification was necessary. The kit provides an etched roof (flat), a sliding ventilator part and a half etched plate for the rear of the roof to represent the section that can be unbolted to enable lifting gear to get to the rear of the drag beam. The cab profile is not an easy shape to form, consisting of a sequence of curves and straight sections. After a lot of careful bending and tweaking I got a reasonable fit onto the cab but it was clear that I'd never get it to sit down perfectly. For fixing I'd considered small screws inside the cab, springy wire clips, micro magnets, but none of them seemed straightforward. The solution I adopted was to avoid fighting the springiness of the formed roof and make it a rigid lid that dropped into place and was retained by gravity and friction. First step was to make some stiffening ribs to hold the cab roof to the required profile. The etched cab roof rib that was already part of the cab assembly was unsoldered, tacked to a scrap of N/S sheet (0.7mm ish) and scribed around, and repeat. Piercing saw and files get you two very stiff ribs of the correct profile that can be soldered inside the roof. The etched rib is the uppermost in the photo below. I included some prongs at the ends of the rib, and they will locate in some slots cut in the cab side flange. One rib was soldered in place just far enough back from the front edge to to be clear of the inside of the cab front sheet. The other sits just in front of the etched cab frame rib. This means that the longitudinal ribs provided in the kit that fit between the cab front sheet and the etched rib can't be used. They don't serve a purpose any more so bye bye. The kit intends the cab roof to be located by tab and slot. The tabs on the etched rib can be filed off and the slots near the front of the cab roof can be soldered up (the two small scraps of brass in the photo below). Now the roof is fixed to the exact profile, there's no springiness and it's become a rigid unit. The other bonus is that it can be held by the rather substantial ribs for the work that follows. With the ribs fixed, their positions on the cab roof flange can be marked. Well, almost. The etched cab sides have a flange above the windows to stiffen the top edge of the side sheets (I guess) and to provide something to solder the edges of the roof to. To prevent distortion of the window frames when the flange is bent there's a long relieving slot etched along the bend line. It certainly prevents the top of the window frames from being distorted but it all but negates any stiffening effect. Also the only areas where the flange is attached happen to be where the roof ribs are, so cutting a locating slot there makes the stiffening flange minimally attached. The remedy is to solder a length of 0.5mm wire inside the bend and fill the slot with solder (dotted line in the photo below). That makes the whole thing far more solid and we can cut locating slots without a problem. The locating slots are circled red in the photo below. If the slots and prongs are matched very carefully the roof can be a gentle press fit into position and be accurately located on the cab. A lot of words, but I hope it's clear from the photos. With that problem solved we can look at the cab roof detail. The Stanier roof is quite a dog's dinner of plates, angles, rivets, rain strips and beading and of course the ventilator hatch. The simple etched parts look a bit 2D and don't do it justice. More hairshirted tomfoolery follows of course. The rear edge of the roof (1/8" plate on the prototype) is finished with an angle section to stiffen it and stop rain dripping on the fireman. The angle is 1-1/2" on the prototype, and that's about 0.9mm in 7mm scale. I represented this with a strip of brass soldered to the edge and filed to shape. Rather than try and position a tiny strip accurately it's easier to solder on a wider strip in roughly the right place and file it back to size. It helps to anneal the brass first to make it easier to bend. Here it is soldered in place. File the lower edge of the strip flush with the inside surface of the cab roof first. Then mark 0.9mm offset from that edge and file the top edge of the strip back to that line. Finally cut the ends off the strip to match the edges of the half etched overlay plate. There's worse to come. The cabs had a beading section running from above the cab side wing plates (to which the cab doors are attached) up the rear edge of the side plate and following the roof edge curves around to butt up to the end of the aforementioned angle section at the rear of the roof. It's a surprisingly chunky section, measuring 2-1/4" x 3/4" with a sort of shallow 'D' profile. That's 1.3mm x 0.45mm in our world. That was made by making some 1.3mm wide strips about 60mm long from a sheet of 0.45mm N/S. There's a lot of bending in both planes and the strips need to be annealed to make that possible. Heat them to a gentle red with the mini torch, pick them up with tweezers and wave them around in the air for few seconds. That cools them fast enough to anneal them fully, and they're very pliable to begin with. I started at the top and worked my way around the cab curves and down to the wing plates. This time the strip has to be accurately positioned so that it's centred on the edge of the roof. No bodgery and filing to shape permitted here. I pre-formed the initial curve along the rear edge of the roof and tack soldered that in position first. Then it was a case of working along pressing the strip into position and tacking. Note that the more you bend and re-bend the strip the more it work hardens and may eventually fatigue through and break. It's easy enough until you get to the last bend where it runs down the rear of the side sheet. The roof has to be placed on the cab to form that bend and because it's quite a tight bend across the flat of the strip it's an a*s*. Because the roof is to be removable the bead strip has to be cut near the junction of roof and side sheet. I chose to make the cut where the bend straightens out. It means there's a little bit of beading projecting from the cab roof corner and the roof has to be handled carefully thereafter to avoid bending it out of shape. The final short straight section of beading on the rear of the cab sheet is positioned to match. When it's all tacked in place it can be carefully soldered along its length. The final task is to create the D section by rounding the edges with files and wet & dry. You can see the break in the beading here, and I'm hoping it'll be less obvious when painted. The roof edges on the prototype were formed up into a semi-circular rain gutter about 5/16" outside radius. Can't really replicate that at this scale, but a flat edge doesn't look right, so a length of 0.3mm brass wire was soldered along the edge and blended in. Of course it's not the U shape of the prototype but it looks the part at a normal viewing distance. The etched part for the roof vent was a bit clumsy so a replacement was made from a scrap of N/S closer to scale thickness. It took a bit of research to figure out whether there was any detail on the ventilator. The cab drawings in the Wild Swan book show that the whole ventilator hatch was riveted together. Eventually I found a good photo looking down onto the roof of a Black Five which had an almost identical cab. Looks like the small rivets were flush with the surface and don't show at all. There were four bolt heads along the rear edge and they were made from 0.5mm wire soldered through holes and filed down. Here's the finished roof in position. A lot more work that I'd imagined, and I hope the Modelu crew appreciate it when the scaleseven Toton drizzle doesn't run down their little resin necks.