Part one
So, you would like to have a go at model engineering? Well, the first thing to do is to make a plan of what you want to do, now and later. There is just one word of advice here, do not be too ambitious. It takes some time to get to the standard of those pictured above. A high proportion of models are not finished because people do not realize how big a commitment they are taking on. That 7 1/4in. gauge express locomotive, or 4in. scale traction engine is mighty tempting. But if you only have the odd hour or two in the evenings and weekends, it would take you a lifetime, although you will most certainly give up a fraction of the way through.
Before you do anything read one of the model engineering magazines for a while, or even better buy some second hand complete old volumes, to get a feel for what is involved in making various types of model. Building something in metal is on a whole different scale to making a model aircraft, or boat.
Then ask the question, what type of model do I want to build? First? Eventually? Do you really want to build it, or is the attraction the idea of ‘playing trains’ or taking a traction engine for weekend rallies? If so, then why not buy a ready made one? They are truly incredible value, with a very nice second-hand locomotive costing just a few thousand pounds, a few percent of what it would cost to commission an engineering firm to make one for you. Because most models are built by amateurs they do not command ‘professional’ prices, even though their quality might be every bit as good. In the past, most models were built by trained engineers as a hobby. Anyone buying a second-hand model built by a skilled toolmaker should be highly satisfied. However, as a nation we have all but abandoned engineering apprenticeships, and the generation of time-served engineers is getting thin on the ground. Fortunately, the fascination of a steam or I/C engine still inspires plenty of men, and occasionally (and brilliantly) women, to take up model engineering.
So, unless you are only going to buy and run a ready-made piece of craftsmanship, decide how much time you have to devote to your hobby. Be honest. If it really is just a few hours a week, admit that you are limited in what you can do. Bearing in mind that the castings and materials for a large locomotive can cost as much as a family car, how much can you afford? How much space do you have?
The first option to consider is a kit. If you are determined to build a 5in. gauge locomotive, but do not have the time, a kit might be the answer. Kits can come complete, or in parts, with everything you need and all the ‘difficult’ work done for you. However, this is not like an ‘Almost Ready to Fly’ model aircraft. The ARTF will take a couple of evenings, a locomotive or traction engine kit could take you a year, or more, to finish.
Alternatively, consider starting off with something smaller. A simple steam engine or hot air engine will be relatively quick to build, even if you only have a few hours a week available. It will introduce you to most of the aspects of metalworking that you will need later for that big project when you reach a time of life where the demands on your time for other things is less, and you have more disposable income. Be prepared to change your goals. Like many, once bitten by the steam engine bug, you might carry on with these in their infinite variety rather than move on to locomotives or traction engines.
Another possibility is to purchase a part-built model. Sometimes, these are a good way to short circuit the path to a finished working model. However, they can also be a whole load of trouble, so take someone who knows what they are about with you when you view a prospective purchase.
Finally, you might like to do your own mini engineering apprenticeship. Throughout this series we will describe some simple projects to get you working on all the basics you will need to become reasonably competent.
Meanwhile, what is it to be? What do you really want to build?
Steam locomotive
Electric locomotive
Traction engine
Stationary engine
Beam engine
Mill engine
Fire engine
Marine engine
Hot air engine
I/C engine
Car
Fairground items
Gun
Machine tools
… and don’t forget that a ‘model’ engineering workshop can also produce items in full size:
Clocks
Marine engines
Machine tools and workshop equipment
This series will take you through the basics that you will need. You will also need the catalogues and/or website addresses from all the major suppliers to model engineers (prices on this website can be used as a benchmark).
To join a club or not? Many model engineers prefer to plough a lone furrow. However, road steam and loco builders, are usually members of a club, so that they can enjoy the facilities, have their boilers tested and their models insured for public running. For the beginner, too, clubs are extremely useful. They usually provide a warm welcome to newcomer, and help and advice is readily available. Members are expected to give up time and effort, as well as a small membership fee, to sustain the club. The new member will be expected to give as well as take.
Think about it all. Next time we will start making things, even if you only have the sort of tools you find in the average household.
Part two
Just how should you go about starting model engineering. The secret of success, as with so many things, is in the preparation. In this first part of ‘how to be a model engineer’ we will give you the groundwork to get started, and prepare you for your first project - possibly the delightful Stuart 10V steam engine pictured right. You will start building and if you do not have a workshop or tools, don’t worry. All that can come later. The thing is not to start with something big and complex, which will almost certainly finish up as a ‘part-completed for sale’ ad. If you are a qualified engineer, you will be able to skip some of the early stages. But they are designed for you to enjoy them if you do follow them.
OK let’s start.
This is an easy way in to model engineering. You don’t need a lathe, milling machine, loads of tools, or even a workshop.
First things first.
Somewhere to work.
Find a corner of a table somewhere which you can call your own without upsetting the domestic harmony. Ideally splash out 20-quid on a little table, sorry workbench, from IKEA or a workmate type bench with a bit of MDF on top – something you can stow away when not in use.
Next buy a kit. You will have your own ideas about what sort of kit you would like to complete, and here are a few ideas.
The Old Model Company produces a series of kits of engines based on early electrical technology. The OMC-1 Rocking Engine presents a bit more of a challenge than some of the Stirling engine kits around these days which can be put together in no time at all. The OMC engine needs a bit more than that, but the instructions that come with the kit are very clear, and all the parts are high-quality, prepared and organized ready for assembly. No special tools necessary.
The OMC-1 kits cost around £100 and as well as providing enjoyment building it, you will finish up with an attractive working model that will inspire you to greater things, and quite quickly have something to display on the mantelpiece. And you only need some AA batteries to power it. Very satisfying. We know a number of experienced model engineers like these, too!
To see more go to the website http://www.oldmodels.co.uk/ which will also tell you more about the fascinating early development of electric motors.
A great alternative, or possibly addition to an electric motor would be a steam engine. And when it comes to steam engines you won’t go far wrong with one of the oldest names in the business, Stuart Models. Countless model engineers, including some of the very best around today, cut their teeth on a Stuart vertical or horizontal steam engine.
Stuart models are available in three ways. First, as a complete, finished, ready to run model. These are popular as collectors’ items for those without the time, or the inclination, to make one. Secondly, they come as kits of castings and materials to be machined and assembled. Naturally these are a fraction of the cost of the finished item. Finally, and just the ticket for the aspiring model engineer, they come as kits with all the machining done for you. Leaving you the job of finishing, painting and assembly.
Several models are available in that form, including the 10V, Stuart’s most popular and enduring engine and which is powerful enough to drive a model boat about 48in. long. Others include the 10H horizontal engine and the S50 model mill engine. These kits are £300-odd each.
To see what’s available go to http://www.stuartmodels.com/
You will need a few tools: a screwdriver, some spanners, a few small files and a suitable paint brush. Otherwise, everything you need is in the kit.
Again the resulting model is something well worth displaying, as well as occasionally running. You can run it on steam or air. Air supplied by a small compressor (which will find myriad uses later in your workshop) is the simplest way to get it working. Alternatively Stuart Models and others sell ready-made small boilers to feed real live steam to power your engine.
An alternative to a kit is to make a model from scratch that requires little in the way of tools. Visitors to model engineering exhibitions will be familiar with the work of the Guild of Model Wheelrights. They have a little ‘apprentice’ piece in the shape of a wheelbarrow. You may have seen lines of these on display - all made by Brian Young. Brian’s design for the wheelbarrow is freely available at http://www.guildofmodelwheelwrights.org/newsite03/techniques/wheelbarrow.htm
Brian has made no less than1,000 of these delightful little 1:12 models – each in a different wood. Wood in small quantities is readily available from Hobby’s, http://www.hobby.uk.com/catalogue/0015-materials.html as is the brass rod needed. To make the wheelbarrow, normal hobby tools such as a fretsaw and carving tools are used, plus a 12BA die to cut the threads on the ends of piece of the brass rod. You will be able to cut the thread by gripping the rod in a vice or some other holder, with a short length projecting, and holding the die in your fingers and twisting it, very carefully and keeping it straight. These threads a very fine, probably the finest you will encounter as a model engineer. A die holder is not required for these tiny threads.
If you are not keen on wood, why not try it in brass, or some other metal? You will need a piercing saw with a supply of various grades of blade to cut the parts out, and small files to be sure of good shapes and to get a nice finish. Small files in this case could be needle files, and inexpensive ones at that, to be used on brass only later on. For saw and blades see: http://www.shesto.co.uk
These little barrows are also nice to have on display, and will get you thinking rather than following instructions for a kit.
OK so you’ve now made something and you are on the first rung of the ladder, and can’t wait to get on to make that loco or whatever your object of desire is.
But first you will need a workshop.
We’ll look at that next time. Meanwhile enjoy your electric engine, steam engine, or wheelbarrow.
Part three
Now let’s get down to a workshop.
If you’re well off and have space, send for your builder chappy and have him put you up a 30ft x 15 brick built shop with underfloor heating and lots of natural and electric lighting. And a leather armchair at one end. Oh well we can but dream.
For most of us something smaller will have to suffice. At one time people used to advocate a spare room in the house. That does not seem a great idea these days, unless you live alone in the middle of nowhere. You would tread swarf all through the house, which will reverberate to the sound of electric motors. That sort of thing doesn’t go down with either the domestic authorities or your semi-detached neighbours. Although I do remember one friend whose ‘workshop’ was the space under the stairs and just big enough for a Myford. At the other extreme, one of our top model engineers today has a large three-roomed basement, which is marvellous.
Indoors is tricky but an outbuilding is perfect. As long as it is more than a few feet wide and does not have some in-use ceramic equipment from Doulton at one end. But remember old outbuildings can be damp and in need of some repairs.
Damp is the enemy.
For most of us the word ‘workshop’ is synonymous with ‘shed’. Don’t be tempted to buy a cheapie from the local DIY emporium. You are probably going to finish up with some thousands of pounds worth of machines and even more on tooling and metals not to mention a model that has taken thousands of hours. A flimsy garden shed may be OK for the mower but not for our gear. If you have to put down a new concrete base for the shed, make sure it has a damp course, paint it with oil proof paint, and use it as the floor as that will be much better to stand machines on than a wooden flooor.
You have two choices of workshop material – wood or concrete. Forget metal or plastic. Concrete sheds slot together like Lego and the result is substantial – sort of an instant outhouse. There is one drawback, they are prone to condensation. However, good lining and insulation plus some background heating should see to that, plus a de-humidifier (good investment in any workshop). Its quite a bit of work – but you should probably give a wooden shed the same treatment even tho’ its less likely to have such a problem with condensation. Concrete workshops also offer greater security – they are much more resistant to a sharply delivered size 10.
However, the wooden shed really does have a lot going for it. It should have substantial frame timbers (good shed makers usually offer an alternative to those used on standard garden sheds). The cladding should offer good protection and the roof and floor should be tongue and grooved boarding.
How big? Size is everything. If you’re just starting it will probably need to be 50% larger than you think. And be warned, everybody runs out of space eventually!
A few thoughts on size. In days of yore all you needed was a bench and Myford ML7, and you really can do pretty well everything with that, fitted neatly into a 7 x 5ft shed with some storage, a small bench drill, and an off-hand grinder. If you are planning to make clocks, that’s still all you need today.
However, if you are planning larger, more complex things you will need something much larger. Even a small milling machine might need a working area of 4x4ft plus space to stand in front of it, access all round, and somewhere for all the accessories. Then there’s the power saw, shaper, 5/8in capacity drilling machine, sheet metal forming equipment, surface grinder, bandsaw, linisher, arbor press, and so on. So, much planning is called for.
When planning, make a good allowance for somewhere for you to stand in front of every machine and bench. Have fun trying to lay out your machines on squared paper. You’ll find that a 7ft wide shed will allow you to fit in much more than anything smaller. And if you’re building locos or traction engines, they take up a lot of room on their own. We do know of one workshop just 8x5ft which has been used to produce some wonderful locomotives in 3 1/2in gauge. Some say he builds them vertically!
Having decided the size and type of shed, and erected it there is still some work to do. Even a T&G floor will need a substantial layer of top, say 3/4in ply or MDF. The walls and ceiling will need to be lined – say 3/8in MDF or ply and the space between filled with some insulation from the local DIY shop. Mark where the shed frames are located for fixing heavy shelves. Paint the inside white. Install lighting and power points (lots at above bench height), and heating. If you do this yourself you must have it passed by a qualified electrician in the UK. Make sure the door fits well and is draft free. Put in whatever security is appropriate – alarms, locks, Rottweilers (this one is called Mischa).
That’s it.
Next time we’ll look at what to put in it.
Meanwhile, enjoy your shed.
Part four
So you’re standing in the nice new shed, sorry, workshop. Small init? If you haven’t actually got your workshop yet, go to a shed shop and stand in some sheds of different sizes. Looks a lot different than an exercise on paper! Better still use the garage, suitably lined and lit. It’s the worse place to put a wet car, anyway.
What to put in it?
First thing is a bench. This is the most important part of the workshop and where you will spend most of your time. It must be substantial.
If you are handy with wood, make it to fit the available space from 4 x 4in timber for the legs and 4 x 2 for the top, and 6 x 1 for the frame. Cover the top with a slice of MDF to make it smooth. Then cover that with a layer of flooring vinyl or rubber sheet, or best of all a piece of old fashioned linoleum. Plain dark green is best – 12 BA nuts can be hard to find on a patterned surface. Use it for the floor as well, at least for the areas you stand on.
If you are not into carpentry, buy a pair of two-drawer-high filing cabinets for use as pedestals – more drawers is better but still effectively the height of a two-drawer unit. Place a suitable length of kitchen worktop on top of the cabinets and glue batons round the underside of the worktop to hold it in place. Voilla! Instant bench and storage. Lockable cabinets are a good idea.
Or take your chequebook to your local tooling supplier and buy a ready-made metal workbench of suitable size.
You should fit a vice to the bench. For most of us an engineer’s vice with 100mm wide jaws is the norm. Vices are available is all sizes and configurations for special needs, from vices that swivel to large blacksmith’s vices to tiny jeweller’s vices.
Your standard engineers’ 100mm bench vice can come in two main types, and here you will need to come to a decision whether you are a workshop perfectionist, or a practical metalworker. The main difference is in the material it is made from. Inexpensive vices are made from cast iron. The good ones are made from steel. Whether you want to invest in a top vice says a lot about you, and whether you are prepared to pay between five and twenty times the price of the cast iron cheapy. Visit a good model engineer’s workshop and I’ll bet you find a steel one from a well-known brand. Are they mad? No, I also bet they bought it second-hand. Whichever type of vice you buy, make sure that its jaws are removable (usually held by two screws).
If you’ve ever used a quick release vice, you’ll never settle for anything less.
Your vice/bench compbination should be arranged so that the top of the vice is about level with a file held in your ’natural’ hand with your upper arm vertical and lower arm horizontal.
If you save some money on your vice, spend it on your hand tools. Over the years, you will probably amass dozens of these, but to start with, here is a suggested selection to start with for general model engineering use.
Start shopping!
•Quality hacksaw designed to take 12in. blades. Blades of 18, 24, and 32 teeth per inch (or tpi) with plenty of spares unless you buy the new bi-metal type from Bahco. Old style blades break very easily in the hands of a beginner. The two with the higher number of tpi are used for cutting thinner sheet metal, there should be at least three teeth always in touch with the metal being cut. An Abrafile saw and blades will also come in handy for cutting curved shapes.
•Odd workshop calculations, such as what tpi blade to use, are made easier if you keep a jotter pad handy, or perhaps keep a black or white board in the workshop.
•At the time of writing tools sold using inch measurements are becoming obsolescent in British industry, and metric tooling is often cheaper than imperial. However, most models for which plans are available have been designed in inches, and you will have to decide whether you will work in metric or imperial units, or both. Fortunately, conversions from one to t’other are quite straight forward, and while thread sizes are not interchangeable, it is not too difficult to decide whether you can replace 1/4in. BSF threads on your project with M6 threads. Buy a basic set of metric drills, or inch drills, or both.
•Files. You will accumulate lots. Start off with 10in bastard cut hand file, 8in. hand second cut, and a 6in. hand smooth cut. Also 8in. second cut files in various shapes, round, half round, triangular, and square. Do not buy cheap files. Vallorbe/Grobet from Switzerland are the sort of files you will find in a toolroom. Wooden file handles come in sizes to suit. To fit the handles heat up the tang of the file until it is red-hot using a blowtorch. Remove the flame, and hold the file at the cold end, upright on a solid surface. Locate the centre of the tang in the centre of the handle, and steadily push down until it reaches a position where just part of the tang can be seen protruding from the handle, and not right to the shoulder of the file. Be warned a lot of smoke will be generated. If the file is hot enough, not much pressure will be required. Leave it to cool, and it should stay put for years. If it is loose, saw off a short piece from the end of the tang, put the file back in its handle and bounce the end of the handle on the bench.
•Files must never be used without a handle. File your files in slots in a rack to protect them. Never keep files and other cutting tools jumbled in a drawer. It ruins them.
•File cleaning card. This is a metal brush specially for cleaning accumulated metal particles from file teeth, but does blunt the cutting edges. Much better, but slower, use a corner of a piece of thin brass sheet.
•Later on you will buy a second set of files – and keep one for steel and the newest one for brass.
•Set of Swiss needle files. These are high quality needle files that come in a variety of shapes useful for precision fitting of parts, and can be used without handles.
•At some stage, you might also find a need for a set of Warding files, which are smaller than normal files but larger than Swiss files, and particularly useful in a knife shape.
•If you are planning working on complex shapes, also investigate a set of Riffler files.
•To get a smooth finish after filing, you will also need some emery cloth. Buy several sheets in various grades, and they can be torn into manageable strips for use.
•A pair of 8in. tinman’s snips for cutting sheet metal.
•An 8 oz. Ball-peined hammer.
Now you are almost ready to make something. But first, you will need the wherewithal to mark it out to the desired shape and to locate holes. Here are a few more items for the shopping list:
•6in. flexible steel rule
•12in. rigid steel rule
• Scriber
•Centre punch
•Micrometer: either 0-1in. or 0-25mm, or a digital one will work in both.
•Vernier caliper either 6in. or 150mm, or a dual digital one.
•Bottle of marking blue
•BS2 Slocombe centre drill
•Drilling machine
•4in engineer’s square
•Pair of overalls (aka smock)
•Safety goggles or spectacles and safety shoes
•Broom, pan and brush plus an endless supply of cotton swabs
•First Aid Kit – make this your first purchase!
•Barrier cream and Swarfega
When tempted to buy some really cheap tools, be aware that you get what you pay for. There are exceptions, or course, but much cheap small tooling is dire. Top quality verniers, and mics from Mitutoyo, for example, will last a lifetime and be a pleasure to use. Good brands are good value.
Part five
Let’s make something – something you will use practically every visit to the workshop. Buy some 1.5mm thick aluminium sheet (or 1/16in. or 16 gauge) from which you can cut two pieces that are about 50mm wider than your vice jaws and about 50mm deep. You can easily cut this with the snips in your tool kit.
Place one piece centrally in the vice so that the lowest part of the aluminium completely covers the serrated inside face of the vice jaw and the top of the vice is in the middle of the piece of aluminium. Grip the aluminium in the vice (does not have to be too tight, just enough to hold it securely in place) and tap the protruding piece of aluminium back over the vice jaw using a wooden mallet if you have one, or use a hammer to tap a bock of wood to make the bend.
Now cut the aluminium to make a slit, which runs to the corner of the vice from the outside edge. You can now tap the vertical end protruding from the vice round to the side of the vice jaw. You can also tap down the top to form a corner (you might need to trim the top of the side piece to allow that). Repeat for the other end. Repeat for the second piece of aluminium on the other jaw. Be sure not to bash the side pieces too hard to that as it is difficult to remove these later.
These ‘soft jaws’ will prevent the vice damaging metal you work on in future. As a model engineer you will probably never use the vice without them.
With that first exercise done, you are going to carry out a simple fitters exercise to make a dice papereweight.
First obtain a piece of 25mm square mild steel (or 1in square) .
You will probably have to buy a piece around 300mm long which you will need to cut a piece 25mm long. But first you will need given the basic instructions for the processes involved.
First - how to use the hacksaw to get the pieces to the size you want. Choose and insert a suitable blade in the saw and tension it enough to keep it stable. Mark with a scriber, rule and square, where you wish to cut. Hold your piece of metal in the vice (using your soft jaws) so that the piece you want can be cut off.
Start the cut by positioning the lower half of your left thumb thumb (if you are right-handed) next to the cutting line, to keep the saw blade in place for the first few strokes of the saw. Once the saw has cut a groove, hold the free end of the hacksaw with your left hand and cut right through the piece of metal. Cutting only takes place on the forward stroke, which must be straight and with moderate downward pressure and with the front of the saw held at a slight downward angle. Don’t rush. You want to ‘feel’ the blade cutting not listen to it screech.
Next, file the ends of the two pieces so that they are flat and square with the sides. The technique for filing is to hold the file handle in you natural hand and hold the tip of the file with the other hand. Slowly push the file across the surface, applying sufficient pressure for the file to ‘bite’, and cut only on the forward stroke. Ensure that the full width of the work piece is covered by pushing the file at an angle. The only tricky part is keeping the file horizontal. If the file ‘rocks’ the work will not be flat. Check regularly with the edge of a rule for flatness and with your engineers’ square for squareness. Use a fairly coarse file to get close to your required surface, then finish off with a 6inch smooth file to get a good finish and to ensure it is flat and square. You can cheat a little by using the tip of the file and using it more like a scraper to produce the finished flat. You can get a super finish by draw filing the surface – gently rubbing the file along the surface holding the file at 90 deg to the piece, so that it cuts from side to side rather than from front to back. For a really fine finish complete the draw filing with chalk rubbed on the file teeth, and for a polished finish wrap smooth emery cloth around the file.
Once you have got that first piece square and flat you are on your way to being an engineer. Congratulations!
When you have both ends flat and square and 24mm apart, repeat for the other four sides making sure each side is cleaned up with a good finish. Measure with your micrometer at various points to see how close you can get to 24mm.
Now, on the sides paint on some marking blue (or use a blue felt pen) and mark the positions of a series of holes using your scriber rule and square. Mark it out as a dice with one to 6 on each face. Use you own measurements for the hole locations – might be an idea to do it on paper first (you are now an engineering designer, too) and make sure that the holes will not run into each other. With the hole positions marked, lightly centre punch the hole position. Get this just right – any error will be very visible. If your first centre punch is slightly off line tap it at an angle to get it to the right position. Give all the locations a final vertical tap with the centre punch to provide the location for drilling.
Now you can finish the dice by drilling holes, around 6mm or 1/4in., say 6mm deep, excluding the drill point. If you have split point drills you can drill the holes direct with the full size drill. If you have conventional jobber drills, start the hole using a BS2 centre drill, and then drill full size. Use a countersink or a larger drill to lightly countersink each hole to remove sharp burrs. Give it a coat of wax polish to prevent rust.
When that is done you can check how well it is made by taking two short lengths of silver steel the same diameter as the hole diameter. Measure across them in various hole positions using the vernier caliper or micrometer to see how well you have done.
We have done this without mentioning a machine for drilling. If you do not yet want to invest in expensive machinery you can use a domestic power drill in a drill stand. The workpiece must be held in a vice.
Alternatively you can buy an inexpensive ‘hobby’ type drilling machine to get going. Watch out for some real bargains, like a 12-speed, Austrian-made drilling machine from Aldi for as little as £35! Later you will probably go for a good quality drilling machine costing several hundred pounds, or a mill/drill.
Well, how was that?
Want to continue?
Next time we look at the lathe.
Part six
Next, the lathe.
The answer to your first question is: “the best you can afford!”
How good you are at producing items with hand tools will depend on how well you develop your skills. For machined parts you need good gear, too.
Myford lathes have always been quite expensive, and seem even more so today when there are so many cheap imports from Asia. But these are chalk and cheese. The Myford is designed for serious model engineers. It will do everything you want. Well. Very well.
Also designed for us model engineers is the Wabeco range from Germany. High quality and not as expensive as the Myfords, but more than the cheapies.
Wabeco (right) and Myford machines are highly recommended.
A range of affordable small German lathes is also available from Emco.
Other new machines are mostly of Asian origin.
Exceptions are from the USA, Sherline and Taig mini lathes. The Unimat especially the ‘Unimat Basic’ and the British Cowells are other good compact lathes.
A word about mini lathes. They are small. Very small. They will not be much good if you are into building locos, traction engines, and large stationary engines, or anything else where you need to chunk lumps off iron castings or turn large and heavy items.
Chinese mini lathes (which come from a variety of factories) have sold like hot cakes in recent years around the world. They are dead cheap. If that sort of thing suits your plans, beware of the pitfalls. One of the problems people found was that many of them turned polygons rather than round, although you can replace the bearings to improve that. When they arrive they are usually covered with something known in the trade as ‘chicken fat’ a nasty, sticky grease of some sort. The casting sand has probably not been properly cleaned out either, and you might finish up doing a lot of work before you get it to your satisfaction. Don’t start anything until you have stripped, cleaned and adjusted any cheap mini lathe. One of the model engineering magazines ran a series on how to get the best from your mini lathe, which ran for more than a year! After all that you still only have a machine with limited capacity. In contrast, if you buy a Wabeco, you can lift it off the pallet, plug it in and start turning.
For what you probably finish up spending on a cheap import you could find a decent used Myford from someone at the local model engineering club who is giving up.
Second hand machines, generally, can be terrific value and often come with loads of goodies. If you need size and great precision you can find toolroom type lathes at affordable prices (these should be properly mounted on a concrete floor). Also Myford reconditions and sells second hand machines.
Beware some of the stuff on ebay. A lot of it looks dire. Probably no better is something just re-painted. Never part with cash until you see and collect the machine. Take someone with you who knows what to look out for. While on the subject of ebay, contrary to myth, much of it is expensive. Before buying a book, for example, check with other suppliers such as the Books page on modelengineeringwebsite.com, which you might find less expensive.
One other factor in choosing a lathe is what other machine tools do you expect to have, and how much space do you have? There are examples of people doing great things with just a Sherline or Unimat lathe housed in a cupboard! A Myford lathe does not take up much space and it will do everything that otherwise you would also need a drilling machine, milling machine and even a slotting machine, for. The Wabeco 4000 is also brilliant if you have limited space.
If you plan to get into CNC at some stage, choose a lathe that can easily be converted.
Installing your lathe should be straightforward. Just make sure there is comfortable space to stand in front, and that both ends can be accessed, especially the headstock end.
A good lathe will have installation instructions available. Have a look at these. They will tell you a lot about your lathe. Possibly not to buy!
We are not giving a shopping list for accessories and tooling for your lathe. Its best to get things as you need them. Enough to get you going are a three-jaw chuck, drill chuck, some cutting tools (High Speed Steel tools are fine for most uses) and a toolholder.
Let’s get started.
First thing. Where is the ‘stop’ switch. Remember that!
Are you suitably attired to work with rotating machinery (no loose clothing or unrestrained long hair and wearing eye protection)? Yes, then let’s make something useful.
When you were making the dice, it was probably difficult to know when you had drilled the holes to the right depth. You can make life easier with some depth stop collars. With this exercise, too, there are no drawings. But do make your own drawing before you start. Its good to make things on paper first!
You are going to make a circular collar in mild steel. It is 18mm diameter with a 10mm hole in the centre. It is 8mm thick. A hole will be drilled in the centre of the outside edge through into the central hole. That will be tapped to give a 2BA thread to take a grub screw (a headless screw with a hexagonal hole to take an Allen key).
Buy a short length of, say, 20mm dia or 3/4in dia free-cutting mild steel.
Hold a piece of the bar in the lathe self-centring 3-jaw chuck with about 25mm protruding.
Place a turning and facing tool in the lathe tool post. Adjust the position of the tool so that it can cut along or across the bar.
The tip of the tool must be at exactly the centre height of the lathe. Just how you do that will depend on the toolpost on your lathe. If the tool height is adjustable, that’s OK. If not you will have to put pieces of metal packing under the tool to bring it to the height of the centre of the lathe. As a guide set the tip of the tool level with the lathe centre in the tailstock by swivelling the toolpost into position. When you are happy that the tip of the tool is close to centre height, tighten the holding bolt and return the toolpost to the cutting position.
Move the lathe saddle until the tool point is almost touching the front face of the bar in the chuck.
Select the correct spindle RPM and start the lathe. You will need to look this up in tables to suit your lathe tool, but around 400 rpm should be OK.
With the lathe running gradually move the saddle towards the workpiece until the tool just touches. Slowly withdraw the tool away towards you. It will remove some metal as you do. When clear of the work piece, advance the tool 0.25mm towards the chuck using the cross-slide. Now face the tool across the end of the workpiece right to the centre. If that has not cut completely across the face, repeat the process.
If there is a small piece in the centre, which has not been cut, you will need to raise the tool slightly. If a small bump is left where the tool has cut above the centre, the tool is too high.
With the tool now at the exact centre height, take a final light skim of around 0.1mm, which will give a good finish. Stop the lathe.
Now move the tool away from the bar and then slightly towards the chuck. Re-start the lathe and move the tool towards the outside of the bar until it just touches, and then move it away just past the end of the bar. Using the top slide, move the tool in by 0.5mm and take a cut along the bar around 15mm. Stop the machine and measure the new diameter with your micrometer. Repeat the turning process until you reach a diameter of 18mm.
Next you are going to drill a hole 10mm dia. If you are using standard jobber drills, first place a no 2 centre drill in the tailstock drill chuck. Drill about half way along the taper. Replace with your 10mm drill and drill a little over 10mm deep. Put a slight chamfer on the outside edge to remove the sharp edges. The correct way to do this is to use the top slide at an angle of 45deg. For speed, a touch with a file will suffice (be very careful when using hand held tools near to a rotating chuck!). Put a light countersink on the edge of the hole using a countersink cutter or larger drill.
We now need to cut off the machined part a little over 8mm thick. The easiest way for a beginner is to cut it off with a hacksaw. Of you can set up a parting off tool in the lathe and use that, again making sure it is on the centre line.
Now put the cut off piece in the 3-jaw chuck with a short length (say, 3mm) of the sawn edge protruding. All you need to do is to face off the piece, and lightly chamfer the hole and outside edge. You are working close to the chuck here, and great care is needed. The commonest mistake for beginners is to catch the chuck with the tool or the edge of the top or cross slide. The other one is to leave the chuck key in the chuck and then starting the lathe.
All that remains now is to to drill and tap a hole for the grub screw. Hold the collar in the drill vice by gripping the flat sides. By eye, make a centre punch pop in the centre at the top of the collar. Start the hold with a no2 centre drill, then drill 4mm dia through one side of the collar (take care not to break the drill when it breaks through into the centre hole). With a 2BA tap held in a tap wrench position it vertically in the 4mm hole. Turn it clockwise (keeping it vertical) until it breaks through into the central hole. Remove any burrs created by the tapping process. Thread a 2BA grub screw into the hole.
And that’s that. You now have a drill stop collar for drills of 10mm or slightly smaller. Just slide it onto the drill bit at the depth you require, fix it in place with a grub screw, and use it to drill holes to the required depth.
You can repeat the process to produce sets of stops of 3,4,5,6,8,10,12mm bore. Design them so that they are all 8mm thick, and have wall thickness of 4mm. For an imperial set the bores can be 1/8,3/16, ¼,5/16,3/8,7/16,1/2in.
The video is not text book (never change tools with the lathe running, or pick swarf with your fingers) but it gives an idea of the processes used, with a larger component.
By the way BA stands for British Association, but the threads are based on metric dimensions. You can, of course, use any convenient thread/grub screw combination.
Part Seven
The first thing to make clear about milling is that you do not need a milling machine. It is not that long since most model engineers did all their milling on their Myford lathe. Maybe they progressed to a home-built Dore-Westbury which conveniently accepts Myford tooling. However, the advent of the inexpensive milling machine import has changed all that.
But you can still do plenty of milling on a lathe if you cannot afford, or find space, for a milling machine.
Its very simple, really. Hold an end mill securely in the lathe, clamp the work piece securely (probably in a vice, probably on a vertical slide), set the end mill turning at the required speed and cut away to your hearts content.
However, do take note of the word ‘securely’. Do not try to use an end mill held in a drill chuck, a lathe chuck, or even some types of collet. It will not be gripped sufficiently, however hard you tighten the chuck, and when you start cutting, the end mill will wander out of the chuck and ruin the work. Only hold end mills and slot drills in collets designed for the job or ER series double sprung collets. This applies whether you are using a milling machine or a lathe.
A brief note about milling cutters. They come in all shapes and sizes, but the most common are end mills (which actually cut on the sides rather than the end!), slot drills (which can be fed downwards), and these days the throw-away tri cutters which can be used both to feed down and cut on the side. Then there are ball nosed slot drills that cut on rounded ends, dovetails cutters, T-slot cutters, and Woodruff keyseat cutters. All of these are held in collets.
Other cutters used by model engineers are saw-type cutters, held on an arbor or mandrel and used to cut slots and similar types of operation, and specialist cutters for cutting gear teeth, for example.
Milling on the lathe using a vertical slide is actually quite good. Its quite a rigid setup (especially if the slides not being used are locked) as it does not have much in the way of overhang to worry about. It is overhang that causes problems with some milling machines. You can test a milling machine for yourself with a dial test indicator fixed to the spindle and resting on the table. Pull the machine head and see how much movement there is on the dti. On a poorly built or worn machine there will be movement. So not much use for doing accurate work, then. Now wind the table along and see if it registers on the dti. Again expect movement on a worn or poorly built machine.
Which milling machine?
Unless you are only working in small scale and cutting materials that are not too difficult, do get something substantial. That’s the key to success in accuracy and finish. One of the problems is that milling machines take up a lot of space. A Bridgeport is great but not in a garden shed. Even a small industrial machine such as the delightful Deckel will usually be too big for the home workshop. For most of us the ‘mill/drill’ type of machine will be the choice. There are a number of imports (no longer quite so cheap, though) available from many sources. The earlier comments on cheap lathe imports also apply to milling machines.
Setting the benchmark for this type of machine are the Wabeco range (right). Starting in the UK at about £2140+VAT they are certainly not cheap. But they are good value. The smallest is ideal for the small workshop and will do everything most model engineers will want. Your local club or technical college will probably have a large machine available for those ‘once in a blue moon’ jobs that are too big for a mill/drill.
Part eight
Marking out
Well, you’ve started your apprenticeship. It is hoped you have made something, enjoyed the process, and are proud of what you have done. But now its time to look in a bit more depth at the business of working with metals if you are to make serious models from scratch.
When making components in metal, we need to be able to mark out their shape accurately, and the position of holes. And for that we need some simple equipment.
We need a perfectly flat base on which to work, and surface plates are available in either granite or cast iron. Small is beautiful here. A 12 x 9 inch surface plate will handle most jobs, and lifting it onto the bench does not require a Tarzan in the way that an 18in. square one does. After buying an 18inch one it will remain in the boot of the car until someone strong enough can lift it out! Anything larger will need a crane. An alternative to cast iron or granite is sheet glass. Modern plate glass is is very flat. Some thickish plate glass, say 1/4in thick, will do the trick. As a supplement to the small surface plate a long piece of plate glass, say an old shop display shelf two feet or more long, will come in handy for marking out large items such as locomotive frames, but will need to be used on a flat surface as glass does bend, thick chipboard should be alright, or a kitchen worktop.
Cast iron surface plates should be well looked after and protected from damage or rust. After use a light smear of grease or a thick oil will protect from rust and a wooden cover will prevent it from damage; if it is left on the workbench, as most are, it will be treated as part of the bench so should be protected from dropped and spilled items.
We need to be able to measure what we are doing. For most things all that is required is an engineer’s rule. For most marking out a 6 or 12inch (150 or 300mm) rigid rule one inch wide is best, and for general measuring use, keep a six inch flexible rule in your overall top pocket. You CAN afford to buy the best rules in the world – they are only a few pounds in small sizes. Or you can buy something from a market stall. Your choice!
Now we need to make some marks on the metal and the tool for that is the scriber. You do not need anything more complex than a piece of silver steel about 1/8 in (3mm) diameter, hardened and tempered, and ground to a point one end. However, professionally made ones are much better to use and are inexpensive. But remember the silver steel alternative for when you can’t find your scriber.
To ensure that your scriber marks show up clearly, it is usual to coat the surface to be marked. Marking Blue is the norm. It is a spirit-based mixture that is brushed on and dries to a thin dark blue coating. A thick felt pen is an alternative. Copper sulphate solution was also used extensively in the past. Clever clockmakers coat brass items, such as clock plates, with a thin coating of primer paint, which can be cleaned off with solvent, saving a lot of abrasive cleaning to get those brilliant finishes on good clocks.
To mark out radii and circles, a pair of engineers’ spring-loaded dividers are required and, again, a top quality brand will not break the bank. If you need to mark out larger radii a tool called trammels or beam compasses will be needed, and you can make those for yourself, but a pair of 6 or 8in. dividers will be sufficient for most projects.
We need to be able to mark out lines that are precisely square to a surface, and the engineer’s square is the tool here. About a 3 or 4 inch one will meet most needs. You will probably need to be able to mark out angles at some time and protractors come in a range of designs, and a simple design will suffice for most.
When marking out it is usual to prepare two datum surfaces, which are machined or filed flat and square, and line positions are measured from those. Good accuracy can be obtained by marking the part out with a scribing block, aka surface gauge. You will need to hold your rule square to the surface plate, by holding it against an angle plate. This is another invaluable piece of equipment with many uses and one about 4in high is alright for most things. Adjust your scribing block until the scribing point is at the correct level on the rule. Lock it and it can then scribe the necessary line by dragging the block along with the sharp point on the workpiece. By standing the work on the second datum face another line can be scribed to intersect the first one to mark the position of a hole centre, for example. When marking out thin metal, it can be clamped to an angle plate.
This method is pretty accurate. It is easily accurate to the finest division on the rule (normally 1/64 in. or 0.5mm) and using a magnifier, you should be able to work to around ).005in. or 0.2mm accuracy, which is good enough for most things. However, for greater precision a vernier height gauge is the answer. These are like vernier calipers attached to a base and fitted with a scribing edge. They read to 0.001in or 0.05mm. You can get even more accurate, but for that you need a jig boring machine.
Once hole positions are marked the point of the hole centre should be given a ‘centre pop’. Using a magnifier or jeweller’s loupe position the point of a centre punch at the intersection of the scribed lines,, and give it a gentle tap with a hammer. Check with the magnifier to ensure the centre pop is in exactly the right place. If it isn’t, angle the centre punch to towards the right spot and give another tap. If that’s OK give the punch another tap with the punch held vertically. When you are happy the dimple is in the right place, give it a firmer tap (but not a whack!) to ensure that the position can be picked
up by the drill, or centre drill.
A brief word on dimensions. On older imperial drawings you will see dimensions that only need to be accurate by rule, or holes that are drilled rather than reamed or bored, are shown as fractions of an inch. However, if instead of 3/8in the dimension is 0.375in., or 3.5mm is 3.50mm, that implied that it should be accurate to the ‘thou’ or to the hundredth of a mm, rather than by rule measurement. Unfortunately, today, many drawings produced by CAD, often scaled down from full-size, and all dimensions are often shown to three decimal places because that’s what the computer came up with. That practice is born of designer laziness and most of the dimensions will not have to be accurate to three decimal places and could have been expressed as fractions or round numbers, with suitable allowances made. Watch out, too, for things like a recent drawing which showed the angle of inclination of model locomotive cylinders as 5.194deg. Yeah. Right! It’s unfortunate that these daft measurements are (presumably) put there for the benefit of CAD/CAM people, rather than those who will drill, saw and file their locomotive frames and relish the sense of achievement.
As far as possible, also do check drawings thoroughly for mistakes. Drawings published in magazines sometimes go through periods of clanger dropping. It’s a good idea to follow some way behind any serial and watch out for corrections.
