Nick Dunhill's Workbench - BR STD 3 from a Scorpio kit.
- Thread starter Nick Dunhill
- Start date
Nick Dunhill
Western Thunderer
Some have sloping fronts as well just to make them a bit harder.
Nick Dunhill
Western Thunderer
I have been moving the cab along this week. It was only a 3 day week as I had family commitments.
I assumed that Standard cabs were simple, as the pipework is out of doors. Well I was wrong.
I made a fair bit of interior and decided I couldn't carry on without a roof. Of course all the dimensions of the cab had been changed, so I didn't waste any time trying to salvage etches for the roof.
I ended up cutting and forming three roof panels before I was satisfied. I cut one that was too short to span the roof, and kinked another forming it. The third was fine. I drew round the square section of the cab front and cut out a rib to get the roof panel into the correct shape in the middle, then adjusted the side parts over the diagonal areas of the cab front. When I was happy with the cab front I drew round the profile (before cutting away for the diagonal areas) and made a rib for the rear of the cab sides. I then made a rib for the rear extension of the roof. Next I cut out the front diagonal areas to match the cab front, and added all the ribs on the underside of the roof.
I added the rain strips from 0.5 mm rod and riveted strip and made a roof vent.
Standard roofs are a bit tricky to make.
I spent the rest of the working week adding more cab detail. I found better castings for the reverser mechanism, so will exchange those next week.
I have just got the gauges, AWS gear, window glass and main handrail to fit. Then the cab will need grafting onto the footplate and the whole assembly mounting onto the chassis. Easy!
This job is becoming quite a marathon. There is just about enough in the kit to give a shakey foundation but there's a lot of scratchbuilding done and a lot more to come.
I assumed that Standard cabs were simple, as the pipework is out of doors. Well I was wrong.
I made a fair bit of interior and decided I couldn't carry on without a roof. Of course all the dimensions of the cab had been changed, so I didn't waste any time trying to salvage etches for the roof.
I ended up cutting and forming three roof panels before I was satisfied. I cut one that was too short to span the roof, and kinked another forming it. The third was fine. I drew round the square section of the cab front and cut out a rib to get the roof panel into the correct shape in the middle, then adjusted the side parts over the diagonal areas of the cab front. When I was happy with the cab front I drew round the profile (before cutting away for the diagonal areas) and made a rib for the rear of the cab sides. I then made a rib for the rear extension of the roof. Next I cut out the front diagonal areas to match the cab front, and added all the ribs on the underside of the roof.
I added the rain strips from 0.5 mm rod and riveted strip and made a roof vent.
Standard roofs are a bit tricky to make.
I spent the rest of the working week adding more cab detail. I found better castings for the reverser mechanism, so will exchange those next week.
I have just got the gauges, AWS gear, window glass and main handrail to fit. Then the cab will need grafting onto the footplate and the whole assembly mounting onto the chassis. Easy!
This job is becoming quite a marathon. There is just about enough in the kit to give a shakey foundation but there's a lot of scratchbuilding done and a lot more to come.
Last edited:
Nick Dunhill
Western Thunderer
Loco construction has been constrained this week as we have had builders renovating our bathroon, which is next to my workshop. It is hard trying to concentrate with tiles being bashed off a wall within a metre of my head. Also I didn't do myself any favours by doing aversion building, saving all the hard bits until later!
I finished the last few things on the cab and decided to make the boiler. I have an engineer in the house (for now) and he happily drew me the conical part of the boiler and produced a cutting template to produce the wrapper.
I also made the parallel smokebox section, punching the rivets first. The wrapper in the kit had been rolled without first forming the rivets, so that went in the bin-o-shame with the rest of the etched boiler parts.
I thought the next thing would be to fit the cab to the chassis. I used the bottom of the cab as a datum point and the cab needed a 0.6 mm spacer to raise the cab bottom to the correct height above the rails. I used the kit boxy fixing thingy to screw the cab to the chassis. The next job was to get the buffers to the correct height. I added some 1.5 mm extensions to the chassis frames to raise the front platform to achieve this. To my horror this pitched the upper footplate about 1.8 mm too high (remember I havd already extended the sloping part of the footplate). I shortened the sloping part of the footplate, and moved both cut outs in the valences to clear the mechanical lubricators. The footplate didn't quite reach the front of the cab, and when I'd completed loads of measurements, I realised the rear of the chassis was too long by about 1.2 mm. I cut a strip off the rear of the chassis and then the cab front sat in the correct place with respect to the rear driving wheel centre. More importantly the footplate would now connect with the front of the cab. The slots in the cab designed to accept the tabs on the end of the footplate were too low, so I cut off the tabs. I added some 1.5 x 1.5 mm brass angle to the underside of the footplate to attach it to the cab and to correct the wrong profile of the end of the footplate (remember I changed the angle of the front of the cab).
Finally the footplate sat in the correct position.
I made a new smokebox saddle to place the bottom of the boiler at the correct height, and corrected the cut out in the sloping part of the footplate through which the smokebox passes.
I thought I'd better finish the week by making the firebox. I assumed (there's that dangerous word again) that the profile of the firebox clothing would match the cut out in the cab front through which it passes. I have a drawing of the cab but not the boiler. I reduced the size of the cab drawing on my copier to that of O gauge and cut out a template.
The etch is from the kit.
The GA shows that the footplate edge alongside the firebox slopes, presumably parallel with the firebox (more assumptions). The drawing did show the length of the firebox, so I now had all the 'measurements' to fabricate one.
At this point my son walked into my workshop to announce that he had just got his first engineering job post-uni. I packed up and we drank a lot of Cremant.
I finished the last few things on the cab and decided to make the boiler. I have an engineer in the house (for now) and he happily drew me the conical part of the boiler and produced a cutting template to produce the wrapper.
I also made the parallel smokebox section, punching the rivets first. The wrapper in the kit had been rolled without first forming the rivets, so that went in the bin-o-shame with the rest of the etched boiler parts.
I thought the next thing would be to fit the cab to the chassis. I used the bottom of the cab as a datum point and the cab needed a 0.6 mm spacer to raise the cab bottom to the correct height above the rails. I used the kit boxy fixing thingy to screw the cab to the chassis. The next job was to get the buffers to the correct height. I added some 1.5 mm extensions to the chassis frames to raise the front platform to achieve this. To my horror this pitched the upper footplate about 1.8 mm too high (remember I havd already extended the sloping part of the footplate). I shortened the sloping part of the footplate, and moved both cut outs in the valences to clear the mechanical lubricators. The footplate didn't quite reach the front of the cab, and when I'd completed loads of measurements, I realised the rear of the chassis was too long by about 1.2 mm. I cut a strip off the rear of the chassis and then the cab front sat in the correct place with respect to the rear driving wheel centre. More importantly the footplate would now connect with the front of the cab. The slots in the cab designed to accept the tabs on the end of the footplate were too low, so I cut off the tabs. I added some 1.5 x 1.5 mm brass angle to the underside of the footplate to attach it to the cab and to correct the wrong profile of the end of the footplate (remember I changed the angle of the front of the cab).
Finally the footplate sat in the correct position.
I made a new smokebox saddle to place the bottom of the boiler at the correct height, and corrected the cut out in the sloping part of the footplate through which the smokebox passes.
I thought I'd better finish the week by making the firebox. I assumed (there's that dangerous word again) that the profile of the firebox clothing would match the cut out in the cab front through which it passes. I have a drawing of the cab but not the boiler. I reduced the size of the cab drawing on my copier to that of O gauge and cut out a template.
The etch is from the kit.
The GA shows that the footplate edge alongside the firebox slopes, presumably parallel with the firebox (more assumptions). The drawing did show the length of the firebox, so I now had all the 'measurements' to fabricate one.
At this point my son walked into my workshop to announce that he had just got his first engineering job post-uni. I packed up and we drank a lot of Cremant.
Richard Spoors
Western Thunderer
That's really good news!
Nick Dunhill
Western Thunderer
I went into my workshop on monday and stared at the firebox. I really didn't want to do the hard bit of making the bottom of the firebox clothing sit on top of the frames as the real loco. I put on my big boy's pants and did it. It required a lot of measuring.
I started with where the bottom of the boiler had landed on the saddle, then transferred that measurement to the rear of the boiler. Luckily the bottom of the boiler sat 5.5 mm above the top of the frames and I had a 5.5 mm drill to use as a spacer/support. According to the GA the top of the rear of the boiler sits 1.6 mm below the top of the firebox. I then transfered this measurement to where the firebox top lands on the cab front and could then measure down to where the top of the frames are. I transferred this measurement to the rear of the firebox. Following this so far?
I then took a L section of scrap brass and made it bang on 90 degrees. I tacked it to the front of the cab so it was up against the inside of the frames, and transferred the profile of the frames onto it with a scalpel blade. The profile was then transferred onto the side of the firebox and the measurements checked.....twice.
Bingo
Here's the profile tool
The boiler was then soldered to the firebox and the boiler bands and other details added.
The whole boiler assembly was solderd to the cab and saddle, which was surprisingly easy, as everything was sitting naturally in the correct position.
The next job I had been dreading was offering up the footplate. The footplates were etched parallel, and of course the firebox and rear section of the boiler are tapered. Lots of measuring and trail fitting ensued until it fitted. The toe kick upstand was added before the fooplate was soldered to the front of the cab and the underside of the smokebox.
The last working day was spent fabricating the bit of the ashpan that drops below the bottom of the frames.
I think I have now broken the back of this one. I have to add lots of pipework and handrails and were there.
I started with where the bottom of the boiler had landed on the saddle, then transferred that measurement to the rear of the boiler. Luckily the bottom of the boiler sat 5.5 mm above the top of the frames and I had a 5.5 mm drill to use as a spacer/support. According to the GA the top of the rear of the boiler sits 1.6 mm below the top of the firebox. I then transfered this measurement to where the firebox top lands on the cab front and could then measure down to where the top of the frames are. I transferred this measurement to the rear of the firebox. Following this so far?
I then took a L section of scrap brass and made it bang on 90 degrees. I tacked it to the front of the cab so it was up against the inside of the frames, and transferred the profile of the frames onto it with a scalpel blade. The profile was then transferred onto the side of the firebox and the measurements checked.....twice.
Bingo
Here's the profile tool
The boiler was then soldered to the firebox and the boiler bands and other details added.
The whole boiler assembly was solderd to the cab and saddle, which was surprisingly easy, as everything was sitting naturally in the correct position.
The next job I had been dreading was offering up the footplate. The footplates were etched parallel, and of course the firebox and rear section of the boiler are tapered. Lots of measuring and trail fitting ensued until it fitted. The toe kick upstand was added before the fooplate was soldered to the front of the cab and the underside of the smokebox.
The last working day was spent fabricating the bit of the ashpan that drops below the bottom of the frames.
I think I have now broken the back of this one. I have to add lots of pipework and handrails and were there.