CABARET MECHANICAL MOVEMENT PDF
Feb 22, Automata Resources. Videos. Poultry in Motion · Killer Tomato · How to Make Automata. Books. Cabaret Mechanical Movement (PDF). Buy Cabaret Mechanical Movement: Understanding Movement and Making Automata: Read 15 Books Reviews - resourceone.info Cabaret Mechanical Movement and millions of other books are available for Amazon Kindle. Cabaret Mechanical Movement: Understanding Movement and Making Automata Paperback – April, Making other sorts of three dimensional objects can also be hard, but he extra dimension of.
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Cabaret Mechanical Movement - Download as PDF File .pdf) or read online. TOYS IN WOOD. method for learning about mechanisms while constructing the kits. Our book, Cabaret Mechanical Movement is aimed at students and teachers alike. It clearly . “I wanted to say how much I enjoyed the Cabaret Mechanical Movement book – it explained some complex ideas around Newtonian mechanics in an erudite.
To be fair, there was a pretty good series of pages explaining the basics of gears, levers, cams, etc. I got the impression that this book was written by some academic and not by anyone actually making automata. The book comes off as a rather dry textbook which completely avoids any how-to information.
This is especially apparent with the examples of automata mentioned. Neither the text or the drawings reveal anything substantive. At best, you wind up being only teased.
Perhaps I should disclose that I am a skilled tradesman of some years who grew up working on all kinds of machinery and mechanical apparatus. I can figure this stuff out, but choose not to reinvent the wheel when I can avoid it. This book was a waste of my time. Natan says: It describes the mechanisms that I wanted to know about. It's almost detailed enough. Not quite. Sometimes things that go up and down unexpectedly turn as well.
One has to puzzle out a solution. But it's still a good beginning guide. One person found this helpful. See all 15 reviews. What other items do customers buy after viewing this item? Understanding Movement and Making Automata Paperback. Automata and Mechanical Toys Hardcover.
Designing automata kit & cabaret mechanical movement
Making Simple Automata Paperback. There's a problem loading this menu right now. Learn more about Amazon Prime. Get fast, free shipping with Amazon Prime. Back to top. Get to Know Us. Amazon Payment Products. English Choose a language for shopping. Amazon Music Stream millions of songs. Amazon Advertising Find, attract, and engage customers.
Amazon Drive Cloud storage from Amazon. Alexa Actionable Analytics for the Web. AmazonGlobal Ship Orders Internationally. Amazon Inspire Digital Educational Resources. Amazon Rapids Fun stories for kids on the go. Making Automata is hard. Making other sorts of three dimensional objects can also be hard, but the extra dimension of movement seems to add a disproportionate amount of difficulty.
For most people, especially those untrained in engineering skills, getting to the point where making mechanical devices is easy, can be a long and frustrating task. These things can be learnt. This book does not teach you how to draw a horse, but it does remove the mystery that surrounds the world of mechanisms and the business of making things move.
This book is published by Cabaret Mechanical Theatre, a museum which has delighted its visitors with witty examples of the automata makers art since Also available as a Kindle download: Buy on amazon.
Some Principles, 2. A common example of spring usage would be when you need to keep a lever against a cam so that it follows its profile correctly. In the previous diagram, the lever or cam follower should follow the shape of the cam through the action of gravity but if the cam rotates quickly the lever may tend to skip over some of the low points. The spring helps to ensure that it tracks the shape correctly. Of course, there is always a downside and in this case the spring will also increase the friction between the cam and the follower.
For this reason, springs are often arranged so that their tension can be adjusted. Most door handles have springs inside. In the cam example, a weight would give a constant load, whereas the load would vary with the spring.
It may also be easier to adjust a weight. If you do use springs, you may find yourself making your own from spring steel wire piano wire because all the springs you can find are either too strong or too weak.
Old typewriters and small domestic appliances can be a good source for light springs. Linkages A linkage is a connection that transfers motion from one mechanical component to another.
Sometimes a linkage is a lever. This exploded diagram shows a linkage connecting a crank to a lever. As the crank rotates, the linkage transfers motion to the lever. The length of the linkage will not affect the distance travelled. This mechanism is known as a crank slider. Crank Slider with high bearing As the crank turns it pushes the linkage up and down and from side to side. The amount of sideways movement can be altered by moving the bearing up or down.
Crank Slider with low bearing The closer the bearing is to the crank, the more sideways movement there will be.
The high and low points remains the same. Additional movement in the wings and legs is gained by the clever use of linkages. The wings and legs are levers. They are pushed or pulled by the linkages strings and wires which are attached to the base. When the body of the horse is pushed up and down the linkages give movement to the wings and legs.
This exploded diagram shows a three-bar linkage. It transfers the rotating motion of the crank via bar 1 and bar 3 to a side-to-side motion of bar 2. The pegs beside bar 1 limits its movement and stop it rotating too far with the crank.
The sequence on the next page makes the action clearer. The crank-slider arrangement makes the top of bar 1 describe the shape of an ellipse A. Bar two is a lever with a fixed pivot point at the bottom. Bar 3 connects the other two bars so that the top of bar 2 B approximates a straight line movement. The rotary action of the crank, is turned into an ellipse and then an arc by constraining levers at different points. Going Another Way—The Bell Crank A bell crank linkage is useful for changing an up-down movement to a side-to- side movement or vice-versa.
The diagram shows a crank which pushes the vertical rod up and down. The bell crank rotates around its pivot point and moves the horizontal rod from side to side. The bell crank is really just another type of lever so the amount of movement can be increased by making it bigger or smaller.
You can also make one end of the bell crank longer or shorter to change the amount of leverage. It would be possible to devote a whole book to linkages but we only have space to cover a few.
The ratchet is a mechanism which gives a motion that is not continuous. This is known as stepped or intermittent motion. The ratchet is a wheel with notches cut into it. A pawl pushes against the notches and drives the wheel around in steps. A second pawl or detent stops the wheel from slipping back. Some screwdrivers have ratchets so that you can keep the driver in contact with the screw. You have to set a switch so that the ratchet turns in the right direction for tightening or un- tightening.
In the sequence shown here the ratchet is driven by a crank. One revolution of the crank moves the ratchet one step. So the crank has to turn 8 times to complete one turn of the ratchet wheel. In the diagrams, the dot on the ratchet shows how far it turns with one turn of the crank. The action of the second pawl is important because the ratchet must stop at the correct point to be in position for the next push from the cranked pawl.
The second pawl often has a spring to ensure that it maintains contact with the ratchet. In this illustration a heavy weight can be moved in short steps as the pawl stops the ratchet from turning very far in the anticlockwise direction. A release mechanism on the pawl is provided to allow the lift to be lowered. Head Off Anubis by Paul Spooner The handle turns an eccentric cam which pushes a ratchet wheel around in steps.
This is used to pull the arms forward. Other linkages, levers and a spring complete the mechanism. Anubis takes his mask off in steps to reveal mummy wrappings, but then it snaps back on very quickly. Poisoned Milk by Paul Spooner In this piece the milk is made from leather which is pushed up, rapidly from below. The movement of the leather is what makes the tongue move up and down but when you look at it, the cat appears to be lapping.
The cat laps enthusiastically at the spilt milk for a while. Then it collapses in a heap. The body is loosely jointed and held together by string. When the string is released the cat falls down in a fairly random way. Another mechanism which produces intermittent motion is the Geneva wheel.
This is used in cinema film projectors and cameras to step the film on one frame at a time. Can you see how it works? There is an animation on our website which makes it clearer: cabaret. Use thick card to start with and see if you can make a crank the right size to drive it. A drive mechanism may also involve gearing or changing the angle or direction of movement.
A positive drive is one where the input and output are locked together in synchronisation. A friction drive, as its name implies, relies on friction to transfer the movement. Teeth Locked Together The wheels in this positive drive have teeth around their radial surfaces. Toothed wheels like this are sometimes called sprockets. The teeth engage with the holes in the belt. This means that the driven wheel will duplicate the movement of the driving wheel.
The wheels are locked together. A Frictional Connection The drawings that follow have been simplified for clarity. They would normally have flanges to stop the belt slipping off the sides.
This drive has plain, toothless wheels, so it uses the friction between the radial surface of the wheels and the belt to transfer the motion. A number of factors can affect the efficiency of this type of drive.
If there is too much friction for instance if the belt is too tight the wheels may be difficult to turn. If the belt is too loose it may just slip around the driving wheel and fail to transfer any motion. To overcome the problems of too much or too little friction there is often a mechanism to adjust the tension of the belt.
The tensioning device shown here is known as an idler or jockey wheel. It can move to take up any slack in the belt. It also has the advantage that it increases the amount of belt that is in contact with the wheels, therefore increasing the friction and efficiency. The following diagrams show most of the ways belts can be used. That is, both wheels move at the same speed and in the same direction.
With a twist in the belt you can see that there is more belt surface in contact with the wheel like using the jockey but more importantly, the wheels will rotate in opposite directions. This drive shows a way to change the plane of rotation. The first shaft is turning at to the second. This drive incorporates gearing. The big wheel will rotate more slowly than the small wheel.
Belts for friction drives come in many shapes and sizes. You might use a rubber band on a cardboard prototype but the same principles are used in industrial machinery. V-shaped belts and pulley wheels give a bigger frictional area and increased efficiency. The belts in a workshop pillar drill are usually like this. You can also get polyurethane belts that can be joined by heating the ends. Rubber belts can be bought from model shops and washing machine spares shops. Friction drives are usually simpler and therefore cheaper than positive drives.
However, there is likely to be some slippage between the driven wheel and the driver. This means that the driven wheel will rotate more slowly than it is supposed to. If you need the two shafts to stay in perfect synchronisation you need something more positive. How to Swim No. The belt is twisted so that the arms rotate at to the main shaft. In fact this is a simple friction drive. The plane of rotation is changed from the horizontal to the vertical with the aid of the friction between the two wooden discs.
More Positive Drives Like friction drives, positive drives come in many different forms. Toothed belts or timing belts have teeth which engage with the notches on the pulley wheels.
Chain and sprocket systems work the same way except that the teeth are on the sprocket wheel. Chain systems can usually be adjusted to the right length by adding or removing links.
Get On Your Bike Anyone who rides a bike and uses the gears should understand the relationship between speed and power. When designing a machine you may find that you want some parts to move faster than others. Gearing is used to change the speed but it will also change the power delivered. This notion should sound familiar. Does it remind you of levers? Good, because gear wheels are yet another form of lever.
The teeth on gear wheels are like a series of levers. As one set of teeth disengage another set engage so the leverage is applied continuously. The design of gear teeth is quite a complex subject and beyond the scope of this book.
When you look at the following examples try to think of ways you could make your own versions.
Here the spur gears are the same size, with the same number of teeth. This means the force and speed of motion is the same for both. This is called regulated motion.
Notice that the direction of rotation is reversed. In the more common situation, with wheels of different sizes, the smaller is called the pinion. In this diagram of a rack and pinion gear, the gear wheel meshes with a toothed rack which slides horizontally, This is another way to convert a rotary motion into a reciprocating back and forth motion. In this diagram, the pinion drives the larger wheel. Because the larger wheel has twice as many teeth it must rotate at half the speed but it will do so with twice the force.
If you imagine the bigger wheel as a bigger lever you can see it will have more force.
Free booklet on mechanisms for automata and other projects
If you reversed the situation so that the big wheel was the input, or driving wheel, then you would say that the small wheel turns twice as fast but with half the force. It all depends what you want. These principles of gearing apply to friction drives as well. In this diagram of a worm gear, the shaft has a screw thread on it which meshes with the toothed wheel.
This is normally used to give a very slow but powerful force to the shaft of the toothed wheel. The diagram on the left is a bevel gear. The two wheels mesh at an angle of 45 degrees so that the plane of rotation is changed from horizontal to vertical or vice versa.
The pin wheel gears on the right give similar although less accurate and efficient results and are much easier to make with simple tools. Practical with Computers To make your own pin wheels the first stage is to divide up two circles so that the pins on each wheel will mesh properly.
If, for example, you decide on a ratio you will draw two circles with a ratio in their diameters. In the example shown below the diameters are 20mm and 60mm. Note that this is the diameter of the circle on which the pins will be positioned. This circle is known as the pitch circle. The actual size of the wheels will be slightly larger.
The pitch circles then have to be divided so that the number of pins are also the same ratio. This will ensure that the space between the pins is the same on both wheels and allow them to mesh correctly. In this example we have chosen to have 12 and 36 pins. To find out the angles for the pin positions, you divide by the number of pins. Still Life by Matt Smith The pin wheels in this piece serve two functions. A small pin wheel on the handle shaft drives a larger wheel.
This slows down the action and changes the plane of rotation. Full instructions for doing this are on the CMT web site. Here, the Mill Girl is so surprised by the presentation of a ring from her posh suitor that her eyes are popping out unwittingly. Meanwhile, their relatives are turning in their graves below. One is made from expensive wood, the other is cheap Control Control is a term which is used to describe the parts of a system which accept the input and instigate the output.
Control can be as simple as a light switch and as complex as a computer program.
The parts of a light switch come between the physical action of pressing the switch and the connection of electricity to the light bulb.
The machine may have to work for a specific period or it may need to complete a specific cycle of events. The momentary action that can be registered when a coin passes through a slot has to be converted into something more substantial if we are going to provide some value for the money.
They perform an action continuously and any point in the action is similar to any other. When the time is up the clothes may or may not be dry. To control this type of machine you need a timing mechanism which can count down a specified number of minutes. The timing mechanism is responsible for keeping the motor and heater operating until the specified time has expired. So a timer is another simple form of control mechanism. They may have a reversible drum action which stops the clothes getting too tangled.
They may also monitor the dampness of the clothes and decide when to stop. These are both control mechanisms—the first time-dependent and the second would require a sensor to monitor the humidity.
Then the hand goes back down again. If you used a timer it would have to be set accurately to match the length of time that the machine takes to complete one cycle.
However, even if you did get the timing right it may be possible for the mechanics to get out of synch synchronisation with the timer. A better solution would be if the control system actually knew when the hand was in the end position. When the control system knows what the mechanics are doing this is called feedback.
In this case, a switch could be activated by some part of the machine when the arm is in the up position. The switch would then be a kind of sensor. This makes it easier to think about the design without getting bogged down in too many details.
So, at the simplest level the Disgusting Spectacle could be defined like this: It becomes more useful to design this way when there is some feedback in the control system because you can show the way the feedback will work by adding links between the blocks. Each block may contain another series of blocks, or they may define specific operations. In the Disgusting Spectacle there are sensors which tell the system what position the arm is in.
This shows that the switching of the motor is dependent on a coin being put in and on the arm position.
This is still a simplification. It could be expanded to show that there is one sensor for the up position and one for the down position. Say you wanted to design a lockable cat flap from scratch. How do I let a fairly stupid animal in and out of the house and not allow entry to all the other cats in the area?
You can define the problem. So now you have to go away and research sensors. Now you have another problem. What use is an electrical switch? You need something mechanical to activate the catch on the door. So it goes on. You may even build a prototype and find that there are other local cats that wear magnets. So you may decide that you need a way to make the system unique to your cat. The point is that any method that helps you solve problems is useful. Trial and error, drawing, block diagrams and research all have their place.
A Latching Relay Circuit When you drop a coin into a conventional non-electronic coin mechanism a switch is operated for a fraction of a second while the coin passes it. To operate a machine you need to turn this momentary action into something longer. One way of doing this is to use a relay in a latching circuit. This circuit requires knowledge of basic electrical principles and you should only try it with a low voltage supply unless you really know what you are doing.
A relay is an electro-magnetic switch. This means it uses the magnetism which is produced by passing an electric current through a coil, to operate switch contacts. In the diagram you should be able to see that when the core is magnetized it will pull the armature towards it. The armature is a lever surprise! As it moves towards the core, it also pushes up the bottom contact into the top one.
When the coin is dropped the switch operates which then operates the relay. When the machine has finished the relay is released by the switch Break. This switch also has to operate momentarily so that the circuit is reset ready for the next coin. The break switch usually takes the form of a microswitch.This makes it easier to think about the design without getting bogged down in too many details.
For this reason, springs are often arranged so that their tension can be adjusted. Could contain more specific pictures for implementation. The plane of rotation is changed from the horizontal to the vertical with the aid of the friction between the two wooden discs. As the cam rotates, this information is retrieved by a cam follower. A helpful book with introduction to many useful techniques.
Making Mechanical Marvels In Wood.