Having noted the pattern of rivets in the centre of the cab rear when viewed from above and making use of the photos that Caroline kindly took of the C1 Cab. I was able to come up with a representation of what can be seen.
I was working on the cab roof when Dave Lester posted the dimensions of the snifting valve on my thread on RM Web and casually mentioned that I might like to make one since I had most of the details. Now this struck a bit of a chord because I have always been disappointed with the snifting valve castings supplied in kits and to look at the best I have ‘seen’ is the turned example sold by Markits. I say seen in inverted commas because I have no idea if it’s dimensionally accurate it just looks good. The trouble with Markits, is actually getting your hands on anything from the catalogue.
If I had any suitable bar in stock, I might have had a go at turning one but sadly everything I had was far too thin. I did have some brass tube of just the right OD though so this was pressed into service I cut a length off that I could grip and hold safely and soldered a square of scrap etch over the end and snipped/filed it round. Finally finishing it in the lathe chuck. At this point it became a bit “Triggers Broom” because Mike Trice posted a selection of close ups of snifting valves on locos and I realised that I had drilled the holes in the side too big and too many (the hole size was one dimension that Dave didn’t have).
Armed with more info I made a second cover salvaging the end cap and the 14BA hex headed screw that I had fitted to the first attempt. Next came the base plate and five goes later I had something usable, albeit it to my eyes it seems a bit small at the measurements quoted. I may revisit this once I have the chimney fitted.
This is what it looks like.
Finally one with the obligatory 5 pence piece for scale – small ain’t it?
I have to say that I had immense fun making it and learned a few things about my lathe in the process.
I haven’t managed any modelling today but I had a really productive day at the bench yesterday. I will appologise in advance that this post is going to be a bit photo intensive.
I started by cutting the recess in the firebox top for the safety valves to sit.
The eagle eyed amongst you will note that I rose to the challenge of the angle beading around the cab/firebox joint. I was sure that I had seen it done before but when I spoke to a couple of the guys that might have done it both sad that they did such things in two pieces. In for a penny as they say I thought the worst that could happen was that I ruin a quid or so’s worth of 1x1mm milled brass angle.
I have to admit I am really pleased with how it turned out and I have no fear of doing it again in future.
Finally one shot to prove that it really is brass angle and not a subterfuge.
Still a bit of tidying up to do and the overlong stud to cut short.
While discussing the cab beading, a gent (Dave Lester) on RM Web pointed me at a photo which shows the tops of the cab and upper boiler of a couple of J6’s and other locos stabled at Hammerton Street Depot in bradford in the period that this loco is destined for (the photo is on page 38 of Great Northern Railway Engine Sheds volume three – I have the three volumes in my library). What the photo lso shows is that the Safety valves don’t just sit on the top of the firebox as you might think from ground level photos.
This is a snip from a scan of the photo that I referred to
As you can see the base of the valves are inset into the boiler clothing and fastened to the top of the firebox with studs. Yesterday’s task was to replicate this with my trusty filed rod and tube.
The next task is to cut out the firebox top so that I can mount this in place – I may need to trim the mounting plate as I had cut it big enough to hold while drilling all the holes with my pillar drill.
Flushed by the success of the washout plugs and covers I deviated from the kit and decided to see if I could make my own mud hole clamps
After all this is what modelling is about for me at least.
I started by taking measurements from the Ragstone castings. Then I found an appropriate diameter tube in my tube stock and cut a 3.9mm length. This I squeezed gently to make the oval and promptly squashed it. I was about to cut another when I decided to have a go at straightening it using a pair of round nosed pliers. A piece of scrap etch provided a backing plate and I drilled a .8mm hole for the stud. another piece of scrap had a hole drilled in it and then filed and bent to shape for the clamp itself. A short stub of tube under the clamp and a nut I made earlier completed it. a few tiny slivers of solder and a waft with the microflame and I had this.
Before closing up the boiler seam I worked on the washout plug holes, mud holes and the rivets/bolts on the side of the firebox – they were interesting to punch out with the boiler pre-rolled.
There are some etches that could be modified for the mud hole clamps but I didn’t use them. I had some nice castings from Ragstone for the clamps and surround in stock. They are round when they come and need to be squashed a little to become oval. I heated them to glowing with the microflame and gently squeezed them in the vice.
Next up I tackled the washout plugs/covers. Again there is an etch provided for these.
They are included on the chassis etch and are nickel silver. Even at half etch they are still quite thick but due to them being hand drawn the spigot that represents the stud and nut was misshapen and not quite central on some. There are six provided where only four are needed so you have a bit of choice.
I decided to use these as the covers but to modify them to have a bit more detail. I soldered them to a backing strip having marked this to ensure that they fit through the holes in the firebox. I had opened these up with a series of broaches and reamers until they were just bigger than the cover plates. I filed off the spigots and punched the centres, then I drilled them with the proxxon. Finally I soldered a short stub of wire in covered by a home made (from filed tube) nut to complete the fitting.
I popped them in the holes in the firebox to see how they fit.
In this shot you can also see the Ragstone clamp castings which I have soldered in place.
I had posted an update of the J6 build over on the Guild forum and Malcolm Stlefox and Dave Lester, kindly pointed out that all GNR engines had beading on the inside of the cab opening as well as the outside so last night’s session was to add the internal beading. Oddly it only took an hour to ad the beading with the cab made up and I am sure it took longer than that to add it to the outside while the cab was flat.
Not much to show for two evenings work, but I have completed the sandboxes.
I did the same as Tony and removed the fold over top plate to shape and fit as a separate item. I didn’t have any brass channel to replace the front section so I scored the back with an Olfa cutter and then folded it as designed.
The first one went together without much trouble but I had to have a couple of goes at the second one before I was happy with it. The fillers are the etches provided sat on a short section of brass tube which I squashed into an oval with some pliers.
Despite being head cook and bottle washer at the minute I have found a little time to pick up the J6 again.
The cab of the J6 has half round beading both around the cab opening and, after studying photos closely, around the front of the cab too. – On the cab etch there is a half etched lip for both and initially I thought that the one at the cab front was to allow for the front to fit better but realised that on the other side were half etched dimples in rivet locations which meant that the half etch would be on the outside not the inside where it would need to be if the cab front sat in it. This lead me to have a look at the photos more closely and note the beading on the front. Despite seeing Tony’s recent build I was doubting myself.
The kit has options to build both the Ivatt and the Gresley versions of the J6 and I am building the latter. The kit has two wrap over cab etches and two etched beads, (because the cab openings were a lot bigger on the Ivatt version). Having seen Tony’s build I elected to follow his lead and use half round soft brass wire instead of the etch supplied to give more shape and definition to the bead.
Because of the need to shape the bead around the cab openings I added it while the cab was still flat. the half etched guide on my cab was slightly over etched in places so it made for an interesting job but enjoyable task. Despite carefully finding the centre and measuring the start of each bend I still needed to do quite a bit of adjusting of the bend before it sat nicely on the front.