Black Five, Jinty or 4F - 3½" or 5" gauge - for a Beginner?

Hi,

Why three 4Fs, well, I sold the first, after which my wife asked what I proposed to do next, so to avoid decoratng and gardening I said I'd build another two, one each for my sons. although I've had every comment you can imagine from fellow club members from "are you still trying to get one right?" to " did you buy too much black paint then?"

Cost is a factor and not given to spending fortunes with suppliers on castings etc after building a number of locomotives it can generally turn out to be far easier to machine something from stock material. I the case of the three 4F's only wheels and cylinder castings were purchased the rest from steel stock and axleboxes, chimney etc from cast iron section. Shop around for materials is the answer, even the auction sites can sometimes come up trumps, exhibitions, rallys etc, keep an eye out in the ME for what's on; I managed to buy enough tube for the boiler barrels at a Guildford rally for less than £25!

The 2P was I think described in Don Youngs own magazine Locomotives Large and Small, it's well worth trying to locate the relevant issues even as a reference tool.

By the way, the 31/2" Jubilee by Martin Evans is in fact a Stanier 2-6-4 tank not the 4-6-0 tender locomotive as one would expect; althought his design is good one and runs well.

Regards,

Bob Y

A note for dithering and anyone else thinking of building the Derby 4F or the 2P, the description of the cylinders, valves and valve gear in my Q1 articles will be of help as I based it all on Don Young's proven design, only slightly modified to suit the dimensions of the Q1. Axles, axleboxes and hornguides ditto. Parts available from Polly Engineering are reasonably priced. The 4F construction series published in ME during 1975 contained no photos of any of the construction, thanks to modern electronic decices I took plenty, this may be useful reference.

Nick Feast

Bob,

I like the fact that you made whatever you could from scratch rather than using castings. I've never been sure why people use castings - is it just to reduce the amount of work or because the parts simply cannot be machined using hand-controlled equipment? You seem to have found that they can so that's encouraging.

Reducing effort isn't my aim so I will be making what I can and I will not be using laser-cut frames.

I have the construction notes for the 2P which is why it's so high up my shortlist.

Nick,

I'ld be interested in the Q1 if it wasn't Southern and the ugliest locomotive ever built but I'll certainly look at your construction articles. In fact, I've just been doing so.

Thanks also for the warning about the lack of photos in the 4F contruction details. I think I'll scratch that one from the list at the moment which makes it 2P versus Ivatt.

Regards,

Brian.

Hi Dithering,

As librarian for BSMEE we have evey volume going back to No1 and as long as David has no objections copywright wise I can dig them out for you.

Now to the subject on hand. 3.5 fiddly have built 3 . 7.25 built one never again needed a engine hoist to move around.

5" just nice building a Thompson B1 Springbok which can be moved around nicely. now makeing all the "Fidely bits" Helen of Western steam is makeing the boiler.

So my concensus is 5"

Bob

Hey Brian,

According to the other thread you've started so what is it to be?

Actually, Bazyle, it could still be either the 2P or the Ivatt because the frame steel is the same for both.

I'm actually going to start on the Ivatt. I'm starting small - buffer beams rather than main frames - so I can still change my mind.

Even the buffer beams are a problem, The Ivatt needs 1" x 1" x 1/8" BMS and I can't get any. The best I can do is 30mm x 30mm x 3mm black steel. I can machine the 30mm down to 1" but 3mm is thinner than it should be.

On the other hand, the 2P requires 3/32" mild steel and (so far as I can see) it just don't exist!

Lifes's a bitch isn't it?

Having seen how many holes need to be drilled in the main frames (particularly on the Ivatt) I decided that a DRO is a necessity so I spent most of this week fitting a scale to the x-axis of my milling machine. I'm just about to start on the y-axis so I can put off actually cutting metal for a few days more.

Regards,

Brian.

Hi Brian

Dont worry about the 3mm steel it's only 8 thou smaller than 3 mm just keep the internal ditance between frames as the drawing. My 5 inch Stirling only has 3 mm frames and they seem ok. By the way 3/32 inch is near enough 2.5 mm.

Good luck with the build

Peter

Hi Brian

Dont worry about the 3mm steel it's only 8 thou smaller than 3 mm just keep the internal ditance between frames as the drawing. My 5 inch Stirling only has 3 mm frames and they seem ok. By the way 3/32 inch is near enough 2.5 mm.

Good luck with the build

Peter

Hi Everyone,

The decision's made - it's going to be the Derby 2P. The reasons are that it's rather pretty and looks easier to build than the other candidates.

The one problem is the amount Reeves charge for the castings. It isn't the money, as such, but the fear of machining £200 worth of cylinder castings and possibly ruining them!

Bob Youldon has made LMS 4Fs (which are very similar to the 2P) by machining most things from stock but not the cylinders. I have seen a couple of items on the web referring to people machining their own cylinders - has anyone here done that?

So far as I can see, none of the cylinder castings should be difficult to make from stock other than the cylinder block itself and even that just looks like a solid lump of metal in which you have to drill a lot of holes. I assume that the bores are cored but is anything else? Can it be machined from solid brass or, preferably, cast iron?

(Does anyone know why it always has to be gunmetal or cast iron rather than mild steel, brass or even aluminium?)

Regards,

Brian.

Steel rusts like crazy, aluminium corrodes around the steel screws, brass is ok but wears though still plenty of Mamods around, bronze is perfect but expensive so that leaves cast iron which used to be dead cheap when every town had a foundry. Strangely cast iron does not rust anything like as quick as mild steel.

If you make your own patterns there is still some chance of getting them cast.

Thanks for the comments Bazyle. Corrosion doesn't worry me because the cylinders aren't likely ever to get wet!

If, in the next year, I can get to the stage of having a rolling chassis running on air (see www.youtube.com/watch?v=0tQRtnREiCg) I shall think my life has been worthwhile. Whether I ever build a boiler is another matter.

Now, I'll come clean here. If you have the latest issue of ME, read the letter from Eddie Jenner. He sounds lke he could be my twin brother.

Many years ago I bought the parts for a Gauge 1 loco "The Project". More recently, but still quite a lot of years ago, bought the parts for a horizontal mill engine called "Tina". I haven't started on either of them and the reason is the same - I'm scared of machining the castings and ruining them. At the moment they have a value - I could sell them. If I ruin them they won't have a value and I don't like that idea.

At the last model engineering show I attended I told a man from SMEE about this. He couldn't help because, frankly, he couldn't comprehend the problem. He didn't lack confidence - I do.

So I would prefer to make something that doesn't need expensive castings and the two questions are:

1. Can I machine a cylinder block from a solid block of metal.

2. If I used aluminium (because it is cheap and readily available) would it work on air - at least for a while.

If I can get the thing working on air I think I would have the confidence to do it again properly. Time isn't an issue. Not getting it badly wrong and giving up in despair is very much an issue. Screwing up a cheap block of aluminium doesn't count as getting it wrong. Junking a £200 casting definitely does.

Regards,

Brian.

Hi Brian

I'm sure it is quite possible to make your model without the use of any castings however it is likely to be much easier and quicker to use some. It is surely just a matter of confidence. You say that you have an extensive workshop and have experience in restoring the equipment you have purchased to good order but it sounds like you have not fully explored the possibilities it offers. It's a bit like a diver - as he progresses he needs to move up to higher boards and probably needs to steel himself for that first dive from the 3 and then the 5 metre platform! Whilst I can appreciate your reluctance to risk " junking" expensive purchases you don't need to put , as you say, £200 at risk! The casting suppliers will provide parts of engines not just the full set.. Why not pick a small ( cheaper castings) stationary engine and buy just the cylinder and, maybe, steam chest casting from Reeves, Stuart, Polly Model etc . and treat it as an investment and learning exercise ? The basic principles are just the same for all cylinder castings. I'm sure you will find it easier than you imagine.

Regards

Norman

Hi Brian

Try polly engineering for the cast iron cylinder block for the Q1 . It isa a solid block of cast iron with 2 cored holes, not very dear and I think could be used with the 2P.

Good luck

Peter