Make do and Mend - Keeping going

[2512silverfox]

I used to see Gerry Brown of Martlesham quite regularly at the time that he made the masters for this kit and for the J27. In both cases the dimensions were gained from original GAs and Pipe and Rod Drawings. Gerry was quite particular about accuracy and all of his masters were, at that time, well ahead of most of the competition.

Adrian Swain produced the castings which were also pretty good.

I built a batch of the J21s in late 1976 although I did replace the awful cast chassis with a scratch built brass affair.

[drmditch]

I used to see Gerry Brown of Martlesham quite regularly at the time that he made the masters for this kit and for the J27. In both cases the dimensions were gained from original GAs and Pipe and Rod Drawings. Gerry was quite particular about accuracy and all of his masters were, at that time, well ahead of most of the competition.

Adrian Swain produced the castings which were also pretty good.

I built a batch of the J21s in late 1976 although I did replace the awful cast chassis with a scratch built brass affair.

Thank you Silverfox. Now I've got most of the locomotive rebuilt, the quality of the castings shows. As far as I can check, the key dimensions are all spot on to the drawings. In my original build I think I got the body about 2mm high on the chassis, probably to avoid electrical shorting. It's remarkable how the boiler being pitched too high distorts the view of the model. This time, everything seems to fit together properly. I have reduced the cast boiler bands though.

The most difficult problem has been fitting in the wiring, what with all the internal motion between the frames. I made a special junction box to fit in the firebox, which allows current collection on the centre and rear wheels, but running wires back to the tender was a bit tricky. (I usually keep loco and tender live to different sides.) However, that seems to be solved now.

Currently it runs better forwards than backwards, but it's quite fun to see (with a strong back light) the rods and links moving.

I think I can roughly dimension the piston valves (under the cylinders) from photographs. My drawings only show the slide valve versions. Does anybody know of a drawing showing the piston valves on a J21?

[drmditch]

Slow progress in the hot weather, and with such a small prototype with a lot crammed in between the frames, it is getting quite tricky. In relation to the above posts though I should say that I’m not entirely convinced by the Nucast dome, but I’m not going to change it now!

The piston valve block was more difficult than I expected. Since in OO there is only just over 12mm between the frames, whereas there should be 4’ (ie 16mm), the result is very much a compromise. However, it does give the impression of the original. I’ll take more pictures on my next visit to Shildon. The best ones I have aren’t mine, so I don’t want to re-produce them here.

The brakes are proving difficult as well, especially the rear ones. They are made from Mainly Trains etches and I am still hopeful I can re-produce the external brake pull rods without them being too fragile.

I just want to get it finished now. The (rather blurred) picture below does show some of the internal motion. It is quite rewarding to see it in action!
Then it will be back to the Alexander kit, I’ve already made most of the Joy gear for it, and that will be much easier to see!

[drmditch]

Well, all summer while the world's attention has been focussed in big 12 wheel engines with sloping fronts, my workbench has been occupied with something a bit smaller, but much longer lasting! It's not quite finished (and dropping the tender didn't help), but here are some pictures of the locomotive which is ready for numbering and weathering.

For some reason I've got totally carried away by detail on this model - there's quite a lot to put onto a small 0-6-0 if you try a bit. Since it has got a working simulation of inside valve gear it seemed silly to miss any external detail. I even tried hard with the cab!

The worst thing to do was the external brake rigging, but it is done, and the loco does go round corners!

(The wires are to provide for electrical connection to the tender, this allows me to collect current from five wheels on each side.)

Left to do are:-
Carriage heating hose under the front buffer beam (left until the front coupling is decided)
Front coupling
Tender brake gear (aided by a helpful answer on the Locomotive and Rolling Stock forum Here

I've just spent the morning on the tender handrails and lamp irons, including the very distinctive NER upper lamp iron which was very finicky to bend and solder up.
I'll put up more when it's actually finished. Despite the complexity between the frames it still seems to run adequately.

[manna]

G'Day Gents

Great looking engine,I hope that it pulls as good as it looks, excellent,

manna

[Horsetan]

I was going to wait until one engine was finished before I posted this, but it’s taken quite a lot of work so far, and from (when viewed from some angles) I am quite pleased with it.

There are two J21s on my workbench at the moment. One is a new build Alexander kit, which will be built as a non-superheated, slide-valve, Joy geared version. I developed a plan to give it a representation of its internal motion, adapted the frames, and built some of the components. Then I realised that the gearbox I had planned wouldn’t fit, so while I was waiting for a new one to arrive I started to re-work a much older Nucast kit.

I had had doubts about the accuracy of this kit (at least as I had first built it), but after a putting it into a glass of paint stripper, I was pleased to find that the basic dimensions (especially boiler diameter) seem to be correct. I’m working to a Beattie drawing from RM, and a drawing reproduced from ‘The Engineer’ of 1887 reproduced in Ken Hoole’s ‘Illustrated History of NER Locomotives’. This drawing, which scales to 7.5mm to the foot, is of course of the original compound locomotive, with Joy gear, of which more later. The Nucast kit will be superheated with Stephenson gear, and having started the ‘works’ for the earlier loco, I decided to try and see if the same techniques would work with this one.

Three weeks (and a lot of fiddling later) here are the results.

Post_02.JPG

The basic idea is to make a sleeve for the centre axle (the driven one on the prototype) with two eccentrics, one on each side. These were soldered up out of brass tube I had in stock, 4mm and 7.5mm OD respectively. There are two large washer plates inside the eccentrics and in the gap between them is a hole drilled through the sleeve and through the axle. A locating pin can then be used to fix one to the other.

Post_01.JPG

Connecting rods were then made up from brass, with an effective ‘eccentric strap’ to fit onto the axle sleeve. (The lower parts in the photograph.) This means that as the axle rotates, the rods have 3.5mm of backward and forward movement, this being the difference between the centre of rotation of the axle and the eccentric. For connecting rods this is obviously cheating. The scale movement should be 8mm, and they should bear onto a crank not an eccentric. However, my micro-engineering skills are not up to making a crank axle, whereas my chosen technique only demands bench tools and a little patience!

More properly driven by same eccentrics, two other rods (correctly the Forward Eccentric Straps) were made up in the same way. These have forked ends, and a short rod representing the Lifting Links are riveted (loosely to allow movement) inside the fork.

The trickiest part to make was the Reversing Bar arrangement, which was made out of more brass tube, rod, and sheet. The frames need considerable work as well, with a new motion plate with slots supporting the end of the connecting rods, and a dummy cylinder back plate. This last is in the wrong place, but this was dictated by the rest of the kit. It does allow slide bars, and even (and these are simple to make and very tricky to fit) a representation of crossheads.

Well, you can see the result, if you can interpret my photography.

Post_03.JPG

I have left out the Backward Extension Straps, the Expansion Links, and the Piston Rods. Obviously the Forward Extension Straps and the Connecting Rods should not have the same centre of rotation on the axle.

(There is also the offset bend in one of the straps is more pronounced in the photograph than I had realised – and no I’m not going to dismantle the whole thing to straighten it. It will only be visible from directly underneath anyway!)

However the result is moving components under the boiler, although you do have to watch closely to see them. You can even see the crossheads shuttling two and fro between the front splashers.

Most of what is left to do is conventional white metal kit assembly, although I will have to make a representation of the Piston Valves between the frames at the front.

Post_04.JPG

So, when I’ve finished this loco, I can revert to the Slide Valve engine, and I think there will be more obvious movement with that one. (Except that I used the motor I’d planned for that one on the Piston Valve version – so it may have to wait until I can afford another Mashima can motor.)

Anyway, after all that I thought that other people might like to see this technique. It is adaptable for any other internal motion, and would be really good for a loco with outside cylinders, internal Stephenson valve gear, and a small enough boiler pitched high enough to give a good view. Anyone fancy re-working an O4?

(Apologies again for my very limited photography!)

Brassmasters use a similar technique for the inside motion in their LMS 4F kit. Works well.

[drmditch]

Brassmasters use a similar technique for the inside motion in their LMS 4F kit. Works well.

Thank you Horsetan, I hadn't found that previously. Since the 4F has it's valves on top of the cylinders there's a bit more to see, and they've obviously left out the connecting rods, and shown both forward and backward extension straps. I'll keep that solution in mind if ever I do this with another loco. It might be worth surgery to an O4, but it would look really good on a V/C6 - if ever I get round to making one.

[mick b]

52F Models do a nice etch for the Lampirons inc the rear one

[Horsetan]

Brassmasters use a similar technique for the inside motion in their LMS 4F kit. Works well.

Thank you Horsetan, I hadn't found that previously. Since the 4F has it's valves on top of the cylinders there's a bit more to see, and they've obviously left out the connecting rods, and shown both forward and backward extension straps. I'll keep that solution in mind if ever I do this with another loco. It might be worth surgery to an O4, but it would look really good on a V/C6 - if ever I get round to making one.

Connecting rods and crossheads are included in the Brassmasters kit.

[drmditch]

Sorry - I do worry about my eyes - looking at small photographs - and trying to find small parts on the carpet!

[Horsetan]

Don't we all.

I put together a crank axle for a Collett Goods some months ago - the hardest part was trying to silver solder the cranks on the axle itself. Everything else was fine.

I do think we need some decent inside cranks for things like J27s.

[drmditch]

Presumably, turning a crank axle up from solid shouldn't be too difficult for a CNC lathe.
Perhaps if enough people got together for a bulk order it might be possible to get batch made?

[Horsetan]

Presumably, turning a crank axle up from solid shouldn't be too difficult for a CNC lathe.
Perhaps if enough people got together for a bulk order it might be possible to get batch made?

I'd probably be the only one in that group.

The NER cranks for the J27 are roughly 7.6mm diameter in 4mm scale.

[drmditch]

Nearly finished. Still to do are - tender brake standard and fire-irons, connecting hose under the LH side of the front bufferbeam, touching up painting (including that annoying gap under the cab roof that only shows up in the photographs), and weathering.

Those tasks are just waiting while I sort out an annoying intermittent short-circuit in what is quite a complex tender. The tender is live to the opposite side to the loco, but also has two wiper contacts. One of them, (or possibly both of them) is/are occasionally touching something live - and I can't quite see what at the moment. Probably one of those problems that's best left while one does something else, and then viewing with a fresh set of eyes!

It doesn't do to handle this little engine too much, especially with the Nu-cast white metal coal rails.

So, here is 5033 as in late 1947. (Actually the photograph on Yeadon 47A page 59 has to have been taken between 28/09/48 and 10/12/48 but it seemed the best one to work from.)

I did have another post on the locomotives and rolling stock thread about NER brake tender brake rigging, but foolishly I managed to delete it after some useful answers. Apologies to the people who were so helpful.

5033's tender was changed sometime after 1948 to the four coal-rail tender she still has at Shildon. Despite the drawing for the external tender brake rodding, with the diagonals outside the leading and centre wheels being about 1906, some 3038 gallon tenders kept the older inside rigging. According the photograph 5033's tender was still in this condition in 1947.
My photography doesn't really show them, but all the tender brake-hangers and blocks are there, together with all the rods and a representation of the handbrake mechanism!
(and I only discovered the short after everything was soldered in place!!!!!)

So, a J21 with a superheated Dia67B boiler, Westinghouse and Vacuum brake, and with it's number hand-painted in Gill Sans. I'm going to do something simpler next!

[drmditch]

The sun was shining briefly and I had the camera out so I took a few pictures of my Q6, since there has been some recent mention of these splendid engines elsewhere on the forum.

This doesn't really belong under the 'Make do and Mend' title, because it's a perfectly standard Dave Alexander model, but it's the best engine for slow running I've ever built. It crawls round the upper level of my layout with a train of coal hoppers all day if I let it. It's also very quiet so it doesn't disturb Radio4!

Sorry (again) about the quality of the pictures. The sun went in when I started taking them, so I had to lighten and sharpen them a bit.)