Make Your Own Amazing Mechanical Toys E-Book

Michael Screen

• Herausgeber: Crowood
• Kategorie: Lebensstil
• Sprache: Englisch

Veröffentlichungsjahr: 2018

Beschreibung

This practical book is a guide to making five kinetic, mechanical marvels. It combines basic mechanical principles with shaping and fitting components crafted from timbers and manufactured boards. An introduction to basic motion and mechanisms such as cams, cranks, levers and linkages to generate motion and movement in a wheeled toy is given. Useful construction and workshop techniques such as production aids for wheel-making are covered. Step-by-step instructions explain each project so that a simple push or pull action will magically bring the design to life. An essential guide to the workshop, including useful power tools for the toymaker and craftsperson. Includes: qualities, characteristics and uses of timbers and manufactured boards: painting and finishing techniques, and ideas to bring your designs to life. Superbly illustrated with 141 colour photographs.

Leseprobe

Michael Screen

THE CROWOOD PRESS

First published in 2018 by The Crowood Press Ltd Ramsbury, Marlborough Wiltshire SN8 2HR

www.crowood.com

This e-book first published in 2018

© Michael Screen 2018

All rights reserved. This e-book is copyright material and must not be copied, reproduced, transferred, distributed, leased, licensed or publicly performed or used in any way except as specifically permitted in writing by the publishers, as allowed under the terms and conditions under which it was purchased or as strictly permitted by applicable copyright law. Any unauthorised distribution or use of thistext may be a direct infringement of the author’s and publisher’s rights, and those responsible may be liable in law accordingly.

British Library Cataloguing-in-Publication Data

A catalogue record for this book is available from the British Library.

ISBN 978 1 78500 512 1

Acknowledgements

I would like to give my sincerest thanks to my partner Isabelle for her invaluable help and encouragement in editing and preparing the text for submission. I would also like to thank her father Paul for his photography and exceptional Photoshop skills. Finally, I would like to thank the countless students, both young and old, who have unwittingly served as my toy-making guinea pigs over the years.

CONTENTS

INTRODUCTION

1 TIMBERS AND MANUFACTURED BOARDS

2 TOOLS AND MACHINES

3 BASIC MOTION AND MECHANISMS

4 TIPS AND TECHNIQUES

5 PAINTS AND FINISHES

6 THE FANTASTIC FROG

7 THE HUNGRY HOUND

8 THE RETRO ROVING ROBOT TOY

9 THE CRANKY CROCODILE

10 THE ROAMING RAPTOR

11 DEVELOPING YOUR OWN DESIGNS

INDEX

INTRODUCTION

Are you looking to develop your ambition as a toy maker and craftsperson? You may be an aspirational hobbyist, semi-retired or retired, an educator, a practising craftsperson or a student looking for inspiration: this book shares some of my skills and experiences as an educator, toymaker and craftsperson of over thirty years.

What could be more satisfying than designing and building your own mechanical timber toys? They make amazing gifts both for children and for not-so-young family members. Your playthings will be given a name, and will be cherished, played with, and hopefully passed to a new generation. They will develop the endearing patination of age and use as they progress through their lifetime.

Perhaps you lack the confidence to currently develop your own mechanical toy ideas, or are looking for a challenge to produce more sophisticated examples. Mechanical toys are the perfect synthesis between craftsmanship, engineering and artistic expression. You have a plaything with its own beautiful mechanical action, and sounds that don’t need batteries or mains electricity to make them function. It is always fascinating to watch the input motion being converted into walks, wiggles, shakes, snaps, rattles and rolls. People love to examine them, to try and unravel the mystery of what is essentially a simple piece of wooden engineering.

The toy maker has a considerable repertoire of techniques and materials at their disposal for generating movement and character in a plaything. Many materials and processes are available, as even a glancing look at historical toy making will show. People have always used the indigenous materials and skills available to them, generating a rich and varied range of toys from different times across the world.

This book focuses on the production of five kinetic wheeled toys operated by a push-and-pull action, with timber as the primary construction material. They are not, strictly speaking, automata, which tend to be remotely operated with a more complex mechanism and generally operated by a hand-turned crank. The projects in this book use wheels, cams, cranks and linkages in various combinations to generate some beautiful mechanical actions when the toy is pushed and pulled.

Mechanical toys require only small amounts of material, such as offcuts and recycled timber, and can be produced in a relatively small space. You will also find in this book information on surface finishes, techniques and treatments to make your toys look amazing. This book will give you clear, concise, step-by-step instructions to produce five practical, kinetic toy projects, shown within these covers. Each chapter is filled with detailed step-by-step illustrated guidelines to produce a well made, functioning outcome. The book also contains advice and strategies to help you develop your own confidence and creativity. The only prerequisites to developing your toy making are access to rudimentary tools, and a workspace with a stable, secure worktop and vice.

Finally, timber toy craft production also offers an ethical and aesthetic antidote to the ruthless blandness and banality of many modern, massproduced, injection-moulded plastic toys.

CHAPTER ONE

TIMBERS AND MANUFACTURED BOARDS

Hardwoods and Softwoods

There is a bewildering range of timbers available to the craftsperson, each with its own unique physical and mechanical properties, which make it suited to any given application. It’s tempting to launch into a dry, arid, academic description of timber as a construction material, but for the purposes of this book you need only know several basic facts. First, timbers are classified as either ‘softwoods’ or ‘hardwoods’ – which can be confusing as some softwoods are hard, and conversely some hardwoods are soft.

The term ‘hard’ and ‘soft’ refers to whether the source of the timber is from a deciduous tree or a conifer, and isn’t necessarily a description of an individual timber’s physical properties. Hardwoods come from deciduous trees, which are slow-growing trees that lose their broad, papery leaves and become dormant in the winter months. Conifers are the ‘evergreens’ with waxy, spiny, spiky leaves which do not lose their leaves and tend to grow much faster. Conifers are classed as softwoods, and include the ‘pine’, which is a broad, generic term for a number of different conifers. All trees produce an annual growth ring, which indicates the quantity of timber produced radially within the trunk during the growth season. Hardwoods tend to produce a narrow, denser growth ring than conifers.

Deciduous trees – hardwoods – include species such as oak, ash, elm and beech, and the tropical hardwoods such as Sapele, mahogany and teak. Largely because of their slow growth, the wood fibres that are produced in the seasonal growth rings are more compact, leading to a timber of greater density. The relatively rapid growth of conifers produces wider, more fibrous growth rings and less dense timber. It’s worth remembering that balsa wood comes from a deciduous tree and is technically a hardwood even though it’s very soft. Conversely parana pine, which is very similar to a conifer, is very hard and durable.

Timber’s Physical Properties

All timbers have their own characteristics, ranging from elasticity, durability, density and ease of working, to name but a few. Some timbers, such as oak and beech, are heavy, hard, dense and difficult to work; they blunt tools easily, but are very durable, meaning they withstand atmospheric corrosion and abrasion well. Some timbers, especially tropical hardwoods, contain their own water repellent and insecticide, making them difficult to glue and giving the occasional unfortunate machinist respiratory problems and a nasty skin rash.

Grain structure and direction also offer some of the key characteristics of timbers. For practical purposes, a straight, knot-free timber often offers the best working and construction properties. People have always prized the beautiful figuring and grain patterns of timbers, and sometimes appearance trumps practical considerations for the most attractive and enduring timber objects.

The Conversion and Drying Process

All timbers are subject to the conversion process, which means felling the tree and carefully removing most of the water. Without this process the timber will shrink and dry out unevenly, causing splits and other defects, including fungal infections such as dry or wet rot.

The tree trunk is sawn longitudinally to form slabs, and then placed in a special kiln where moisture loss is carefully controlled, often over a long period of time. Hardwoods take much longer to grow, and require much more careful conversion and drying compared to conifers, which accounts for their higher cost.

Softwoods/conifers are ‘farmed’ commercially in managed forests, and the drying process is accelerated, leading to timbers that can shrink and distort too easily. It’s worth remembering that all timber is always ‘on the move’. This means that wood will shrink and stretch slightly in different temperatures and especially humidity, which is infuriating if you have just built a door, drawer or toy component that fits like a piston, only to discover a little later that it has shrunk by five millimetres or jammed shut! The rule to remember is that wood shrinks or stretches in width, never in length: it always shrinks or stretches across the grain.

It’s worth investigating the properties of timber further, as this will explain a lot about why certain timbers are used for specific purposes, and how they have been used through history. Elm, for example, is an indigenous hardwood with good water-repellent properties used for chair seats, tables and components for boat building. The final factor to consider is availability.

Conifers are easily and readily available in any number of builders’ merchants and DIY stores. They are machined and sold in preferred sizes or specific sectional dimensions and lengths. Softwoods are sold as unplaned, PBS (planed both sides), or PAR (planed all round), which makes marking out a lot easier since you start with at least one true edge and at least two right angles to work from. Much softwood available in these places is European white wood, the softest and most anaemic timber available used for general construction. It is often poorly seasoned, distorted, full of knots (the roots of a branch) and poorly grained. The next stage up is redwood, which is denser and has a pinky/ yellowy colour graining used for better quality construction. The best examples are straight grained, knot free and well seasoned, for which you pay a premium.

Hardwoods are available from specialist timber suppliers and saw mills. They are sold by the cubic foot as raw, seasoned slabs. You need the means to mill and process large pieces of timber if you use these suppliers, though you can often get small pieces for next to nothing. One common feature of many of these suppliers is their occasional and inexplicable indifference, rudeness or lack of cooperation if you exhibit any confusion or ambiguity about what you want. Similarly, I have encountered enormous generosity and selflessness from some yard assistants and sales people. The general rule of thumb is to do some homework and know what you want and roughly how much. Mentioning a few key, esoteric technical terms or words and phrases is akin to gaining access to the Masonic Lodge, and will open the portal to what you require without being ignored or belittled initially.

Finally, the most satisfying, ethically sound and least stressful source of raw material is recycling. Timber toys require little material, which is readily available from broken-up pieces of furniture (just don’t break it up without explicit permission!). Recycled timber is free, well seasoned and often machined to at least roughly the correct dimensions. You can visit the local refuse dump – or ‘recycling facility’, to use the correct term – where the staff often have a local racket going, whereby you can remove, or buy for a haggled fee, items that have been dumped. Beware, some of the staff exhibit the same characteristics as timber-yard staff and need to be handled carefully – so if you shake hands with some of them, count your fingers afterwards!

Timber Structure

Finally, timbers can be worked in two different directions. The first is longitudinally, or with/ along the grain. Wood fibres generally run parallel with each other, making cutting fairly straightforward and easy. The second is cutting across the grain, or at right angles to the grain direction, which is difficult, requiring great care not to split the wood. Wood is structurally stronger with the grain, and weak across the grain. It is important to plan components not to have areas ‘short across the grain’, as this will lead to splitting and snapping. The plans in this book direct you to lay out your templates carefully in order to take advantage of the structural strength of the timber being used.

Diagram showing timber grain structure, and an example of a component that has cracked due to being too thin and exposing too much end grain. This is known as ‘shortness across the grain’.

Timbers for Toy Making

Redwood: A dense, heavy and better quality conifer. The best redwood is straight grained, knot free and well seasoned. It is a pale, salmon pink/yellow colour, and is used for higher quality joinery. Redwood is a good quality, attractive timber, and a more ethical/economical alternative to hardwoods/deciduous timbers.

Oak: A dense, heavy and open-grained timber. It is very hard, making it difficult to work and shape without sharp, well maintained tools. Oak is very durable, making it ideal for furniture and outdoor structures. It reacts with ferrous metals, which cause a black stain to appear in the timber, so brass fastenings and fittings must be used. It is relatively inexpensive.

Beech: A dense, heavy, hard and straight-/ close-grained timber with few knots. It is very durable, takes stains and dyes well, and is used for toy making, furniture, frame works, tool handles, work benches, and components exposed to a great deal of abrasion and impact. It is expensive but easily available.

Lime wood: A light, close-/straight-grained timber with few knots. It is ideal for carving and pattern/mould making. It takes detail really well. It is easy to machine and shape with hand tools, with little splintering or splitting. It is relatively inexpensive and easily available.

Sapele: A tropical hardwood often confused with mahogany. It is reddish brown in colour, slightly oily, heavy, dense, hard and splintery. It can be difficult to work across the grain without splitting. It is used for high quality joinery and furniture. It is expensive and becoming rarer.

Manufactured Boards

Manufactured boards are an engineered solution to counter the defects and faults of natural timber, most notably its weakness across the grain, and its tendency to shrink, stretch and distort; it is also the solution to making a broad, flat, wide and smooth surface. Manufactured boards are available in thicknesses of 4mm, 6mm, 9mm, 12mm, 18mm and 22mm thicknesses. The following are examples of manufactured board materials, and their qualities that are suitable for toy making.

Plywood is constructed from a number of veneers or thin layers of timber. Each layer is bonded, with its grain direction at a right angle to the layer below. This counteracts timber’s natural tendency to shrink, stretch and distort. It resolves the grain direction problem and allows for the production of much wider, broader and flatter boards. Birch plywood is a fantastic manufactured board for toy makers as it is dense, heavy and attractive, and does not splinter excessively like Far Eastern plywood.

Far Eastern plywood: Made from veneers of tropical timbers such as Sapele. It is heavy, hard, dense and very splintery. It blunts tools quickly, and it can be difficult to get smooth, safe edges. Marine plywood is a similar, superior quality plywood product. It is available in thicknesses of 4mm, 6mm, 9mm, 12mm, 18mm and 22mm.

Birch plywood: This plywood is made from veneers of birch timber. It is very heavy, hard and dense, and is much less splintery than Far Eastern plywood. It can be very attractive, it finishes and machines well, and is much more durable than Far Eastern plywood. It blunts tools easily. It is available in thicknesses of 4mm, 6mm, 9mm, 12mm, 18mm and 22mm. It is expensive, but is very durable and stable, and takes staining and colour really well. It is the ‘go to’ material for toy making.

Medium Density Fibreboard: This board is made from wood fibres bonded together to form a heavy, hard, dense and smooth-surfaced timber product. It must be sealed very carefully and thoroughly to prevent moisture penetration and distortion. It takes a painted finish really well. It is available in thicknesses of 4mm, 6mm, 9mm, 12mm, 18mm and 22mm. It is useless if constantly exposed to moisture, and for making toy components exposed to abrasion, or if high dimensional accuracy is needed. MDF becomes flaky and fluffy without careful surface finishing and sealing. It is much more useful for modelling, and for testing mechanisms for toy ideas.

CHAPTER TWO

TOOLS AND MACHINES

It is beyond the scope of this book to give an exhaustive list of tools and processes and how to use them. I am assuming you have at least a rudimentary understanding of these, so I will itemize the essentials for the successful toy maker/craftsperson and their workspace.

• Organize your workspace to utilize it efficiently and to make it safe to work in. Keep the floor clear to avoid tripping, and place things away carefully to avoid the enormous frustration caused by losing or misplacing items

• Ideally you should have access to good natural or artificial lighting

• Learn how to look after your tools! Blunt tools are the most dangerous, besides causing mistakes in your work

• Power tools such as electric routers are a fantastic resource but require careful practice and use. A razor-sharp cutting tool rotating at 30,000 RPM is a formidable opponent when used incorrectly. Routers are second only to the angle grinder for hospitalizing craftspeople and construction workers

• Dust extraction and protection are important if you plan on doing a lot of work. It’s staggering how much wood dust accumulates in a short space of time, especially when using power sanding tools. At least wear a face mask or respirator

• The most basic need when working materials to form any object is being able to hold components safely and securely. Toy making offers the opportunity of working on a relatively small scale but requires some careful shaping and fitting, which can prove difficult without a sturdy vice. My advice would be to get a small, used workbench with a vice, and ideally a portable engineer’s vice (the type used for holding metal components)

• Go back to basics! Be able to work to a line using saws, planes and files. With one flat surface you have a datum point from which to make right angles and the three other, square, true edges and surfaces. This is especially useful when buying slabs of raw hardwoods and no access to a planer thicknesser or a table saw. With confidence you can be much freer and more intuitive by sculpting and shaping in a more expressive way using chisels, drum sanders and rotary cutting tools. The projects within this book make extensive use of drum sanders and rotary cutting tools, which need some practice to develop confidence. A useful idea is to try out techniques on a piece of scrap material first

• All cutting, abrasion and shaping hand tools have their electric equivalent, but it is good to be able to do things the low-tech way before ‘going electric’. The bottom line is that power tools cut out a lot of drudgery, speed up production and ensure dimensional accuracy (if done correctly). As a hobbyist, it can be very satisfying to cut and square up a timber blank occasionally before forming a component, but the repetition can be mind numbing

• Complete fabricating and assembly tasks in the correct order. It’s extremely difficult to locate and drill a hole accurately in an irregularly shaped piece of timber. Drill all holes while the workpiece is flat and easy to hold. Similarly, perform the shaping and fitting stages for projects explained in this book in the correct order to avoid complicating tasks unnecessarily. Each project is supplied with a page of templates which can be pasted on to the timber blanks to avoid complex marking out. Where a hole is required, refer to the required drill-bit diameter and centre punch the location to assist the drill bit to locate the hole accurately. Another example is drilling the holes for axles while the wheel blank is a square, and therefore easier to grip in a machine vice.

Useful Power Tools

All power tools are available in a number of sizes and power ratings. As a general guide, the higher the motor wattage, the more torque the motor will generate. This will allow faster working and ultimately prolong the motor’s life. Cheap, small wattage motors burn out too easily and quickly. The best for the workshop are those that can be bench mounted for the sake of portability and using a limited space effectively. Bigger, freestanding versions are available depending on your budget and workshop size.

The key to acquiring useful tools is to let need direct your purchases. As mentioned above, aim to buy the most powerful wattage, good quality motors, as these will give the tool greater torque and resist burning out. If you are a real purist, continue with hand tools exclusively. Finally, nothing compares to buying tools and machines with money you have made selling your own toys or crafts.

For toy making for the hobbyist with limited space and budget, the following machines are invaluable.

Bench-mounted pillar drill: A number of good models of pillar drill exist at a very reasonable price. Really cheap power tools have poor quality motors, which will burn out with excessive use. The pillar drill also allows a drum sander to be fitted, which is a very efficient abrasive tool.

Bench-mounted bandsaw: The bandsaw is ideal for cutting across the grain or for ripping work (cutting with the grain) if required. You need several blades for different tasks when using the bandsaw.

Scroll saw: Again, this can be bench mounted and enables the operator to cut extremely tight, curved profiles that require little surface finishing afterwards. Unlike the bandsaw, the scroll saw blade leaves few blade marks and doesn’t tear the wood fibre – a component cut with a fine scroll-saw blade needs almost no filing or glass papering. As with bandsaw blades, different grades of coarseness can be used for cutting different materials and thicknesses.

Orbital sander or linisher: These tools are fantastic for sanding angles and chamfers, and can be used with a number of jigs to produce different diameter wheels with the appropriate production jig. They are also criminally neglected as the source of many workshop accidents. An 80-grit abrasive paper will strip your finger tips and knuckles in an instant. Look for ones with a guard, feed the workpiece to the abrasive surface in the right direction, and don’t use too much pressure on the workpiece.

Rotary cutting tools: Several manufacturers offer these tools, with a bewildering range of cutting tools and attachments for a range of materials. It is the most versatile and enjoyable tool to use. The best models are sold with variable speed settings.

Electric router: There isn’t much an experienced router user cannot do with this machine, but as mentioned earlier, get to know it and practise safely before letting loose with it. I have a dedicated router set into a portable table to act as a mini spindle moulder. I once fed the workpiece in the wrong direction, causing the wooden piece to be propelled at high speed across the room before embedding itself into the plasterboard wall.

Wood lathe: This lathe is a fantastic resource if you can stretch to it. You can get very good quality, bench-mounted wood lathes for a reasonable price. A wood lathe can be used extensively for both toy-making and furniturebuilding projects.

The timber penguin toys were made on a wood lathe, cut and reassembled to make them more asymmetrical and lifelike.