Prepared by Tommy Day Originator E. Robson

I am currently attempting a 1st. almost complete scratch build of a G.W.R. 4575 tank loco. I am at this stage now but feel like taking the bunker off again as I am not happy with it, the top corners are the problem. I have built two Scorpio tank locos and the kits had the corners in as castings which made the job easy but they do not do the 4575 class or I would have tried them to see if they sold the corners separately. I have read articles on the construction of G.W.R. tanks mainly Raymond Walleys article but he concentrates on the chassis and more or less said the body went together o.k. Forming the corners is not too bad but it destroys the rivets I have done and putting them on after is almost impossible. I know there are rivet transfers etc. but I wonder how other members have overcome this problem. I know that the model is not perfect and not up to the standard of some of the work on this site, but to me it keeps my mind active and at my time of life that is a bonus. I would appreciate any advice from those who have overcome this problem, Thank you .
Eric r.

Raymond Walley - Jan 19, 2018 at 12:51 PM
I am impressed with your scratch build. Mine was only a kit and, if I remember correctly, the rivets on the bunker were etched in, so not a problem when bending. How are you making the bends that the rivets get distorted though? It should be possible to use finger pressure round a suitable drill shank to achieve a good bend without compromising the rivets you have so carefully put in. Another idea that occurs to me might be to fill the dimples with high heat solder before you start bending.

I shall be interested to see how you get on so please keep posting.

Robson17023 - Jan 19, 2018 at 2:00 PM
Thanks Raymond I find the top and bottom panels are easy to form as you stated but the reverse curve between is the difficult one. I rescued a Pannier tank which the builder had put the panels on with the rivet depressions on the wrong side. I made new panels and did not curve the reverse curve but built it up with layers in the corner and filed the bend round I did not try to put rivets on but I will one day.
I trust you are keeping well under the circumstances.
Eric.

Robson17023 - Jan 19, 2018 at 2:13 PM

Raymond I have made a start on the cab roof details I thought the trim was going to be awkward to cut out so I took a piece of etch which was the right width heated it red with a cooking torch and formed it through my fingers in best Uri Geller fashion .Just got to get the front one the same.
Eric r,

Jim Snowdon - Jan 19, 2018 at 2:28 PM
The only method for doing this properly that I have seen is to use either a casting, which is what MOK provide, and which I believe JLTRT may also provide, or a pressing (which is what the GWR did, to our inconvenience). Dave Sharp at MOK has been prepared to sell castings, assuming that he has sufficient stock, but only as complete casting sprues (which is not unreasonable).
Failing that, which is the position most of us are in, it becomes a case of filling in behind the corner and filing the curve from the outside.
Jim

Robson17023 - Jan 19, 2018 at 2:56 PM

Thanks Jim I looked at the MOK site 14xx class and noted the corner does look like a casting but then the 2 rows of rivets are marked on the panel and the corner butted up to it, I have tried to follow Swindon and put the rivets on the corner piece to get the join between the rivets. Think I will try again. Make a new back end complete then if it works out replace the current one. If all else fails then I will measure up to see if any of the castings will fit and order a pair.

The object was to do as much in house as possible as I bought a lathe from sales and wants off Nick Baines and it had a host of extras which I want to make full use of.
Sorry to the kit makers for going down this avenue. (It was an Ace kit that brought it on ) but I also like a challenge.
Eric.

Robson17023 - Jan 20, 2018 at 6:36 PM
Raymond, the roof was formed cold, the end trim was a piece of 2 mm. wide straight brass strip from an etch waste which I heated till red hot then formed it on edge to fit round the roof. I did try n/s but it kept kinking

For the roof I have made a working hatch but the rails are well oversize .The idea was to open the hatch to access a retaining screw, wish I had worked on watch's instead of heavy machinery.
Eric.

Robson17023 - Jan 21, 2018 at 3:46 PM
I will try around tomorrow to see if I can get the castings separately looking at drawings the smaller locos seem to be Identical and as Jim pointed out the corners were pressed out, if so I could not see GWR. having lots of different tools to make the corners.
At the moment I am going to put the body to one side and concentrate on the chassis as this was put together to make sure the coupling rods and axle holes were o.k.
More details to go on but don't expect a Nick Dunhill job.
Eric.

Robson17023 - Jan 21, 2018 at 10:00 PM

Thanks Raymond ,this is the chassis at present, set up to check that it run o.k.. I am going to add some more details will post progress.

A week on from speaking to JLTRT regarding bunker corners I still await their e.mail with a parts list attached, probably getting ready for Kettering?. so in the meantime I have progressed with the chassis. The springs and brake hangers were in a box of spares I had from a friend who is unfortunately no longer with us. The coupling rods and con rods were alternative etches from a David Andrews Black 5 kit. shortened to suit, The valves on the cylinder ends were made from Slaters pick ups I don't use them as I radio control my loco's. The brake lever was made from laminated etch and was going to be adjustable and was until heavy handed soldering stuck it all together. The vac pump rod is .75 mm. n/s threaded 16 B.A. and adjustable.
Last night I run the chassis on a straight piece of track and apart from having to file the brake hanger ends it ran o.k.
What happened to a simple scratch loco build nothing elaborate I am even thinking of inside valve gear but then as Jim Snowdon said you will only see it if it falls over.
Eric r.

Lamb18400 - Feb 2, 2018 at 11:24 AM
Just as an aside, one of the model engineering monthlies as an article on flanging G.W.R. bunker corners and gives an account using a flanging block, much surgery and brazing.
Guy

Jim Snowdon - Feb 2, 2018 at 12:15 PM
Nothing wrong in what you're doing. I build my models to (a) provide enjoyment (although with some of the kits I tackle, some might question that :eek:), and (b) to work on a layout where they are there to haul trains and be looked at from a sensible distance, not be stared at by a camera at 2“. The principle of if you can't see it at a normal viewing distance, why waste effort modelling it?
That said, when you take a picture, fairly close up, it does rather expose the crankpin nut on the driving axle as woefully undersize. I know it's the one that came with the Slaters wheels, but quite why Slaters went for 12BA I am not certain. Like many, I change mine for 10BA, and tap and reverse the Slaters bushes. If I am feeling really inclined, I will turn up new flanged crankpin nuts to suit, but I accept that not everyone has a lathe (and it shouldn't be a pre-requisite for 7mm scale modelling, merely a helpful addition to the toolbox).
Jim

Robson17023 - Feb 2, 2018 at 3:29 PM
Jim, the front pair of wheels do have 10 BA tapped bushes for clearance, I am going to do the rest and try to turn up some better looking nuts. The object when I started out was to see how much I was capable of making my self. I do normally hold the view that you can't see the detail when it is running on a layout and when it stops at the station you can't see a lot below the footplate. but what I am doing as with you ,is for my own enjoyment. At least I can't moan at the kit .
Eric r.

Robson17023 - Feb 9, 2018 at 10:57 PM

progress on my scratch build steps need finishing, have chickened out on tank fillers and rockers and ordered some from Warren Shepherd. Nothing fastened down yet still some pipework to do on the chassis,Made some crankpin nuts out of brass would look better in N/S. The smoke box saddle was cut down from a spare 61xx prairie tank casting needs more file work to get it to fit neat. Temp. smoke box door made of plastic card.
Eric r.

Robson17023 - Feb 15, 2018 at 9:38 AM

Progress on my scratch build.

The long wait for a smoke box door , bunker formers and other parts from JLTRT. just got longer.I meanwhile contacted Warren Shepherd and ordered some parts from him they arrived very quickly. I did not contact MOK about the bunker corners as I hoped to get to Kettering and have a chat. I will be building a 45xx next and to save time I ordered a set of etches from Warren S.
I formed the bunker corners over a block and trimmed them to fit, won't be doing that again. Another lesson don't use 1/16 th. brass for the chassis too much heat required to solder parts on to it.
Eric r.

Robson17023 - Mar 8, 2018 at 9:52 PM
Some more work on my scratch build. Had to make up the smokebox door from a Warren Shepherd pressing with .70 wire and .70 i/d tube for the hinge it was going to be a casting from jltrt. I will have to do better on the mud hole covers on the fire box they are to big so waiting for some from Mr. Shepherd. I was snowed in up here so did not manage Kettering, stocks of sundries getting low .Roll on Doncaster.

Eric r.

Robson17023 - Mar 11, 2018 at 9:36 PM

A rare fine day in North Durham, managed to get some primer on

Eric.

Robson17023 - Mar 15, 2018 at 9:53 PM
Another fine day and I managed to get some paint on. Sorry about the poor quality photos off my old phone it do'es better pictures out doors but the weather was back to normal today. Now to finish the chassis and put some detail in the cab, was quite pleased with my efforts till I looked at Gerald Wingrove's website

Eric r.

Started on the cab fittings, the backhead came with a pannier that was badly part built, the backhead was too big for the pannier so it went into the spares box. It turned out to be for a 45xx class so on close inspection the regulator and the brake were in the right place there was an unidentified casting soldered where the sight glass should be. This had to be butchered off , the steam fountain was fabricated from copper wire and brass tubing soldering the three knuckles on was a barrel of fun some foul words helped. All the other parts apart from the gauges were fabricated from brass rod and pieces of brass sheet from an old clock case. Not in the Nick Dunhill class but with the roof on it will hopefully look o.k.
Eric r.

Robson17023 - Apr 9, 2018 at 5:54 PM
Made some progress on this scratch build. The homemade gear box ratio was too high , it would have overtaken an A4. so a strip down and another box made works fine now. The pony trucks need downward pressure I made the tops so that a spring loaded wiper would sit on them I did hope the weight would be enough. I made some balance weights for the wheels from black plastikard and used polystyrene cement to glue them on they fell of overnight. Not much more to do now I have the etchings for a 45xx from Warren Shepard but I think I will take a break from rivets for a while and scratch build a Southern railway M7 I made one from card with a plastikard chassis about 9 year back it still works ok but it needs upgrading.

Eric