47xx 5” gauge build and hello!

Hello,

This is my first posting here. By way of introduction, I’m James, I’ve always had a practical background but I’m looking to get into model engineering. I’ve joined a local ME club and spoken to various members as well as doing a lot of internet reading, but have jumped straight in and purchased a set of 47xx plans - this being the engine I’d like to build.
I’m looking to buy a lathe although - as is so often the case, budget is limited to about £400, so it’s not going to be anything too fancy. Any advise welcome on lathes. Would I be able to complete the project without purchase of a mill?
There’s a denham mk2 in the classifieds, would this be suitable for a beginner?

Thanks

James

Hello James and Welcome!.

If you are not familiar with a lathe and machining, my advice would be to delay starting work on the 47XX kit., for a long time.

What follows is intended to help, nio to be condescending, so Sorry if teaching granny to suck eggs.

You have done the right thing to find and join a local Model Engineering Society.

There you will find like minded and experienced people who can give face to face advice and help. Possibly even practical help in the form of tuition and / or demonstration. members will be able to help you choose a lathe.

Where are you located?

Be wary of the shiny "Refurbished" machines, Sometimes the best part is the shiny paint on a badly worn machine or one that has been assembled, not too well or accurately, from All Spare Parts!or.

This is where you need advice from the more experienced.

£400 is either going to buy you a secondhand mini lathe or something a lot older..

Whatever you buy, learn how to use it before cutting metal from your kit.

One of the first things to learn, is to use both hands to provide a slow steady feed, either along the bed for sliding, or across for facing.

Next, you will learn that if you put on a cut of 0.010", the diameter will reduce by 0.020" The lathe will take metal, off the far side when it comes round to the tool!

I learned these things within the first day or so of trying to operate a lathe. Fortunately, I had a very experienced instructors in the Trade School

Be careful! The machine may have only a 1/2 hp motor, but it is stronger than you and can injure you, so keep hands and fingers away from rotating chucks, or drills. If it cuts metal, it will most easily cut flesh and bone!

If you have had a pistol drill "grab" you will already know what I mean!

On a small and particularly an old machine, it will not be suitable for getting the best from carbide tooling. For this carbide needs to run fast, and plain bearings, with drip feed lubrication, in older machines, are not suitable for the speeds required..

So you need High Speed Steel tooling. To keep such material sharp, you need to learn how to grind tools.

Most certainly, you will need to learn how to cope with backlash.

Hopefully, your internet reading will taught you that the tool needs to be mounted at the centre height of the lathe spindle if it to cut properly. So now you are in for a grinder, to come out of your budget.

A good learning exercise is to make yourself a Centre Height Gauge. By making bit, you will become familiar with the machine, and what it can do. You will soon learn that an off centre tool does not cut properly, and leaves a pip in the centre of the job when you face the end.

Make your mistakes on a bit of mild steel rather than on an expensive casting!

Also, you will need measuring equipment. Probably the cheapest that you will get will be a Digital Calliper from somewhere like LIDL or ALDI.

If you are lucky, you might be able to find a secondhand Dial Calliper, or a Vernier Calliper. Something else to learn, how to read a Vernier (Buy a small magnifier, it will help )

Are you going to work in Imperial units? Most likely with an older machine. A more recent mini lathe may be graduated in Metric units, but some are Imperial.

A secondhand lathe might need setting up. A badly aligned machine will not cut accurately or parallel. For some tasks,you are looking for precision of the order of fractions of the thickness of a human hair!

This where fellow club members can help you..

Hope that this is of some help to you.

Howard (AKA Fat Fingers )

Edited By Howard Lewis on 30/07/2022 11:43:42

Have a look in the classifieds, I've advertised an ML7 for a club member with no interweb. It's more than your budget, but negotiable. Depends where you are of course, this is in NW UK

You can research older lathes on here that come up for the right money and in the right area you to collect.

You need to wait and see what else comes with it before you buy anything else at all

James

If your local society is anything like the one I belong to workshops come up for sale a few times a year. When one does have a good look and seek advise.

What really caught my eye is your choice of model. I remember 47xxs working holiday trains out of Paddington. They were truely magnificent beasts but I, personally, would not now consider building one (although I would love to). Even at 5" gauge it is a very heavy locomotive and would frighten me even in the workshop. I did the same as you years ago and bought the plans of Martin Evans's Torquay Manor and then had doubts. I have now started on a Speedy (a copy of another Paddington engine), a little bit lighter and takes up less room.

If you go ahead with it I wish you every success.

JA

Edited By JA on 30/07/2022 17:21:19

Edited By JA on 30/07/2022 17:22:52

Agree that you are very ambitious with your choice of project. Don't underestimate the cost of materials and the time required which will be in the thousands of hours.

Regarding machinery, no, you don't need a milling machine to build a loco, but then a milling facility in the form of a vertical slide for the lathe is essential.

It's also hard to do without a bench drill and a bench grinder. Smaller tools etc. can be acquired as you progress, but it's a lengthy list.

While like those who have already given advice I think you have bitten off a lot you have met probably the most important criteria - You have chosen a model that you want to build.

OK you will need to practice making parts to size etc but you won't be the first person to succeed at an ambitious first model and provided you accept the need to ask for help from fellow club members and are prepared to get some bits wrong and have to remake them you are already on a roll. Just try not to spoil the expensive bits - and even if you do you have only wasted your time and some cash but hopefully learnt a lot.

Learning as you build something that you want is far more satisfying than making a small steam engine just as a practice piece - although a lot of people, including me, get a lot of pleasure from finishing one - and the same applies to making workshop bits and pieces - but the main aim is the 47xx.

Post a picture when you have made some progress.

Dear all,

Thank you all for your replies, it's just the advice i'm after. I have had a wood lathe for years and do understand quite a bit about keeping chisels sharp, feed rate, speeds, grab, even if it's only in wood, although I realise that there's significant differences too.

It had dawned on me that it's ambitious - I was thinking of 7 1/4 gauge initially but i've realised that that'd be far too much - in terms of weight and size just as much as castings size, turning big pieces, etc.

I've a workshop with most of the required 'ancillary' tools already, decent pillar drill, grinder, micrometers,verniers, squares etc but i'll need to adapt to working to a new level of tolerance - with the usual stuff I do if it's within 0.5mm its pretty good!

Howard, as you mentioned, - i think i'll work in imperial. The plans are imperial, but also i'd probably be looking at an older lathe with imperial dials etc. I've worked in both, and am reasonably happy with mixing units but would probably ultimately find it easier sticking with one. How do people find the availability of material in imperial? If I got frames laser cut from 4mm sheet say, would that be a problem later on when the rest of the plan is in inches?

Duncan - i'd seen your advert, although the forum says I need to make some posts before I can view contact details in the classifieds. I'm in NW UK too, whereabouts is the lathe?

Am I correct in thinking 10 years wouldn't be unrealistic as a time frame? (all things considered, errors, remakes of parts and learning along the way?

Thanks all

Nothing like a bit of encouragement ....wow

Depends on the original frame thickness. If the frames were 5/32" then probably no as the 4mm thickness will most likely be slightly undersize anyway. Otherwise you'll need to change the width of the frame spacers to keep a dimension, mostly usefully outside frame to outside frame, the same as the drawings.

It's what I did on my traction engines when I made the hornplates from 6mm plate rather than 1/4". I just made the axle and 2nd shaft tubes 0.7mm wider so the outside to outside hornplate dimension remained the same.

Andrew

Hi James, I have spent many years building up a very well equipped workshop, I haven't even started a steam engine yet! I repair all sorts of stuff in my workshop, the lathe is key to most of this, the one you are looking at is old but so are a good many lathes, check it over carefully, if it's in reasonable order then its definitely worth buying, you'll be amazed how much you will do with it without even looking at building models!

James, pm sent with contact details