Snakes are not everyone’s favourite. Still I think it is unkind to exclude them from the wonderful world of automata. My snake has a sort of cobra pose, head swaying in the air to some invisible piper’s tune. As a very friendly snake it has no fangs and instead has bright pink, kissable lips. A very colourful body adds to its appeal and as a short-sighted girl, a pair of spectacles add a vulnerable touch hopefully calming the nerves of even the most worried visitor.
The Technical Brief
This is a fairly simple construction. Turning the handle rotates the camshaft which moves one end of the the rod connected to the snake’s head along a circular path, making the head attached to the other end of the rod do something similar. Making the central horizontal part of the bearing as wide as possible automatically constrains the camshaft so that it stays in position. No extra parts are needed to prevent the shaft from slipping to the left or to the right as the handle is turned.
The snake itself is a sequence of wooden beads threaded onto a piece of waxed string. A small wooden egg serves as the head, with a hole drilled to glue it to the connecting rod for the camshaft.
I again used 3 mm dowel to pin the parts together before gluing. This makes both the fine adjustment and the painting easier.
With such a wide bearing, the connecting rod up to the snake’s head might slip off centre and jam. I found that making the hole through which the rod passes large enough allowed things to rattle around and avoid any jamming.
In the Sep-Oct issue 2022 of Automata Magazine we showed you Animals in Orbit. As the number of animals has increased over time here in Berlin, this has caused a queue of visitors all waiting for their turn up in orbit.
So, instead of them just joining the lengthening queue to go into orbit, I thought that I would keep them amused by making a seesaw. Yet another way to bring movement to what are otherwise fairly static characters.
Amongst other interesting new visitors, this friendly bee flew in one day out of my wife’s bonnet and decided to stay.
This curious animal is a rare specimen of the teapoticus nervosus, commonly known as the nervous teapot. Lifting its red knob raises the lid to let light right in, often dazzling the poor creature.
So what’s the brief?
For a change, I thought that I would avoid using a box as the base and instead I went for a flat base whilst still opting to turn a small handle to create the up and down motion. To keep the seesaw low, this meant putting the crank mechanism off to the side, with a long linkage to push and pull the short lever between the supports for the seesaw.
The plug-in “seats” for the animals are the same as for Animals in Orbit, just with a different paint job. A wild black and white spiral pattern draws attention to how the movement is produced.
The important bit is the “crankshaft” which transforms the rotary motion from turning the red-headed lever into a to-and-fro movement for the stripey connecting linkage.
Here you can see that I used 3 mm dowel pins and corresponding holes to locate the four sidepieces. Using pins like this means that I can put it together and take it to pieces as often as needed to ensure that the movement is correct. It also means that flashy paintwork is easier to do before parts are permanently glued in place, sometimes getting in the way of masterful brushstrokes!
Ultimately it is the passengers who bring this to life. With no one having fun it is a dull spectacle. It looks best when the animals look at one another, just as in real life, perhaps goading one another to seesaw even higher or even faster. The mechanism is pretty simple and, as usual, the bright red knob shows you what to turn to bring things to life. For small friends who come to visit, Animals in Orbit has become quite a favourite and now, together with this seesaw, the possible permutations and combinations of which figure goes where seem to be endless, and no one has to get bored standing in the queue with nothing to do.
Insects don’t get much of a look-in on the automata front. Most of them have an annoying number of extraordinarily thin legs and aren’t generally as cuddly as cats and dogs, or even Koala bears. I feel this is rather an injustice, so I thought that it’s about time for an automata dedicated to that queen of the insect world, a dragonfly. They are quite showy creatures, glistening in marvellous colours while zooming decoratively around country ponds. I can manage showy, as I have lots of paint in the cupboard, but I decided against zooming about, settling instead for some vigorous flapping of its wings instead. Insects also have quite large eyes but they don’t go in for pupils and irises, preferring complicated compound eyes.
The Initial Design
A selection of ready-made wooden balls and eggs served as the body for my dragonfly meaning that there was no need for carving. Some thin plywood could serve as wings and brass rods for legs. The tricky part is the cam to control the flapping of the wings. If I had used a round cam mounted off-centre, for each turn of the crank the wings would go up and down once. After some experimentation, I chose to triple the number of movements by using a cam with three “peaks”. For each turn of the crank, the wings now rise and fall three times, resulting in a satisfactory flapping movement while turning the crank at a reasonable speed. As usual, you will see that the final result doesn’t quite match the initial design.
A piece of 3 mm dowel holds the 5 pieces together which make up the dragonfly’s body. In total, t’s about 10 cm long. I cut the wings from 2 mm plywood.
Each wing needs two hinges. The first is to attach the wing to the body and is made of 6 mm dowel with a 2 mm hole drilled along its centre. This allows a piece of 1.5 mm brass rod to turn very easily. The second hinge is needed to attach the rod which pushes the wing up. Here, I used a 10 mm ball which was ready-drilled with a 2 mm hole. After sanding a flat on one side of the ball it can be glued to the underside of the wing. The closer together these two hinges are, the more the upward push from the cam is magnified, increasing the amount of flap.
Cutting some small (18 mm) wooden eggs in two with an 8 mm hemisphere on top makes some nice shoes, bent brass rods serving as robust, insecty legs.
I used a 7 mm brass tube to attach the dragonfly’s body to the base. A 5 mm dowel pusher can easily slide inside this. At the top end 2 mm plywood pieces protrude through carefully cleaned slots cut in both sides of the tube. Friction must be kept to a minimum to make sure that the wings do not stick at the top of their movement. Brass rods then link the wings to the pusher.
I used a 20 mm hemisphere as the cam follower on the bottom of the pusher rod.
With the follower now resting on the cam our dragonfly is ready to go. A smart hat complements her trendy shoes and huge eyes let her see where she is going. Nature doesn’t equip dragonflies with pupils in their eyes but I sort of hinted at the multi-facetted structure by using a dotty pattern, and if the centre dot is black, well that’s a bit of artistic licence. Everything else could be quite true to nature!
An unusually warm winter has encouraged a rarely seen species to leave its secret lair next to the pond – the Berlin Dragonfly!
The way that groups of fish move together has always interested me (flocks of birds too, but that is another story). Occasionally I see underwater nature TV programmes which show how a school of fish move like synchronised swimmers or a group of ballet dancers moving together across a stage. I found one definition of a “school” as a shoal of fish swimming in the same direction to then suddenly all change direction at the same time. My question was – how do they do that? Is it telepathy? Is there a sergeant-major fish who yells “about turn!” So I thought why don’t you make yourself a school of fish and see how you can make it “school”, or dance yourself.
Before making anything, I always have a look around hyperspace, to see how others approach the same challenge. It’s boring to simply copy someone else’s work, but seeing what approach they take and how the finished item works out is always an education and often an inspiration. Entering “fish automata” into a search machine, I found quite a few matches. Two impressed me in particular: one with just a nice single fish by Carlos Zapata (https://cabaret.co.uk/fish-2012-by-carlos-zapata/) and another quite complex one with a big school of fish by Matt Smith (https://www.youtube.com/watch?v=CGaj_KlXFqs).
Trying to keep things as simple as possible, I thought maybe I could use a cam to make the fish wiggle. I then decided to let the operator choose in which direction the fish should swim instead of automating a fixed routine of direction changes. Simply turn the crank one way to swim left and turn the crank the other way for the fish to swim right. The operator of the automaton then becomes the choreographer for our fish ballet school.
I used the Graphic app on my computer to produce scale drawings. This took up most of the time as I kept modifying things as I noticed where bits might bump together, or where gravity might pull parts in the wrong direction. It is hard to follow drawings which you didn’t draw yourself, but together with the photos they should make some sense.
For the drawings I used a different colour for each moving part. – The yellow part is the crankshaft which is turned by the operator. – The red, green and blue parts each carry two fish at the top (not shown). – The brown part (the wiggler) holds the stops which limit the movement of the red, green and blue discs. – The grey parts are fixed and don’t move. As the camshaft is turned, the three yellow wheels drive the red, green and blue discs, turning them until they encounter the stops on the wiggler.
The top view follows the same colour scheme but doesn’t show the crankshaft or the box. The grey circles represent wooden hemispheres which act as lengthened bearings for the brass rods, which each hold two fish. I thought these looked like upside down octopus so, to reinforce the effect, I added a 3 mm thick set of arms to each one, which accounts for the odd, grey star shapes. The six small brown circles in the wiggler show the 3 mm dowels which protrude downwards to act as stops, limiting the rotation of each coloured disc.
The side view shows the yellow cam responsible for wiggling the fish, four times per rotation. The brown part is hinged at the bottom and a free-running wheel ensures smooth movement as the cam turns. Imagine the cam pushing the wheel and thus tilting the brown part outwards, towards the front of the base. This moves the stops towards the front. The low points on the cam allow the stops to move back towards the rear, encouraged by a spring (not shown).
The fishy, yellow part to the right is part of the external crank which the operator turns.
One of the advantages of producing drawings is that you can print out and then cut out templates, which speeds up things in the workshop.
Base – top
This is what the underside of the top looks like.
The purpose of the hemispheres is to lengthen the bearings (holes) in which the long brass rods sit. The rods must turn easily in the bearings but should stay vertical. Longer bearings keep the rods straighter whilst still allowing them to turn freely.
Brass rods to hold the fish
Here are the large discs responsible for turning the fish with pieces of dowel protruding from the edge which restrict the amount of turn, when they hit the stops on the wiggler. The long brass rods are carefully fixed, vertically, into the discs using two-component epoxide adhesive.
The camshaft has two identical cams at each end and, between them, there are three drive wheels, each driving one of the discs on the end of a brass rod.
This strange looking thing holds the stops to restrict the rotation of the large discs. It is hinged near the bottom of the base and the spring pulls it against the two identical cams. As the cams turn they move this gently forwards and backwards. The slight movement of the stops causes the large discs to move a little, which in turn make the fish wiggle a little. It is the wiggler.
The assembled mechanism
When assembled, the stops on the wiggler are positioned so that they can catch the protruding dowels in the edges of the large discs. For each disc there are two stops. One restricts clockwise movement, the other counterclockwise movement.
I carved the fish from lime wood and added fins made of 3 mm plywood. After cutting each fish into four pieces, I used a fretsaw to cut a slot upwards in each piece, making space for a piece of flexible tape. Some careful gluing later and the fish wiggle in quite a fishy way. Two fish are mounted onto each brass rod using two component epoxy resin adhesive.
The painted base
Some underwater vegetation builds on the aquatic atmosphere, as does carving the supports to hinge the wiggler as clams. My clams have eyes which makes them a species as yet unknown to science. As the spring is not fixed here, gravity pulls the wiggler away from its intended working position.
Final assembly & reflections
For this project, with an eye on future repairs, I chose to not glue the box together. Instead I used 3 mm dowel to pin the parts together while doing the fine tuning and painting. Once painted, I used brass screws to more permanently hold things together. Making things of wood is great, but wood does react to the moisture levels in the air. This has occasionally caused some of my fully glued creations to jam up, and repair then means having to destroy certain parts and then remake and repaint them.
Leaving the box without a front or back wall leaves the mechanism clearly visible for the many curious.
This looks quite complex, but there is not much to it with just a few moving parts. I now even suspect that one cam would probably have been enough to move the wiggler, making it even simpler.
When my seven-year-old quality control expert tried it out, she played happily with it for quite a long time. It is not really child-proof as the temptation to grab a brightly coloured fish and move it yourself is almost irresistible for small hands. The 2 mm diameter brass rods are fine for adults, but children would need something much more substantial. The fish are also not terribly robust. We will see what time shows. Other makers have used wire rings to join the fish segments together. Maybe that would be a bit sturdier.
I am currently making a fish automaton, which will appear in a separate article, and I was considering what sort of fish swim around in the sea and what shape and colour they are. A lot of fish have much the same shape, you know, sort of fishy looking, long and sleek with fins and tails. Two exceptions swam into my mind, the first was a seahorse and the second was an octopus. I am sure that I will sometime have fun trying to make a seahorse automaton, but I couldn’t resist pushing the fish to one side and knocking up a simple octopus.
It doesn’t take long to make an octopus as they only have a head and eight arms. I used a wooden egg for the head, sawing the pointy end off to make a flat surface. In this flat surface I then drilled eight holes into which I glued eight pieces of string. Each octopus arm is then made up of 9 wooden beads which I found ready drilled and painted in a hobby shop. I suppose they were intended for children to make a necklace or a wrist band with a bit of elasticated thread. To make a friendly impression, my octopus has a nose and an external mouth with a slightly puzzled expression. I apologise in advance to any biologists who have a better understanding than I do of what is essential for an octopus in its life down in the ocean depths.
As my octopus has eight dangly arms, the simplest movement is to spin it around so that the arms flail outwards. I decided to add a bit of up and down movement to produce some sort of undulation and make the movement what seems to me to be more octopus-like.
A small, open box is enough to contain the mechanism driven by a crank.
We need two wooden discs, one mounted horizontally and the other vertically. You can see that the shaft for the larger disc is mounted off-centre on a 2 mm brass rod. This eccentricity is what is required to produce the up and down movement.
For each turn of the horizontal shaft its eccentric disc turns once and so pushes the smaller disc up once and allows it to fall down once. The eccentric disc is thus acting as a cam. It could have a more complicated shape to, for example, increase the number of up and down movements per turn. This quite simple mechanism gives us just what we need to make the octopus both spin and move up and down, producing the undulating effect we are after.
In the finished item you can see that a couple of plastic washers keep the eccentric disc turning smoothly. I have also painted some very small fish around the circumference of the smaller, driven disc. It would be a bad idea to paint the eccentric disc as the abrasion as it drives the other disc would rub the paint off.
Youtube link https://www.youtube.com/watch?v=YPYMaLMjkJQ
This suggested using a crankshaft to make the raindrops move up and down and I thought, “I’ll go for that” but, along the way, I decided to embellish the design with a rainbow, a sun, a cloud and ultimately a small bird.
A rainbow is a simple geometric exercise and I chose to have 6 colours. As a boy I learned Richard Of York Gave Battle In Vain to name the sequence of seven colours in the rainbow, red, orange, yellow, green, indigo and violet. I have never understood the difference between indigo and violet, so I decided to drop indigo leaving just six colours.
The cloud was fun. Cotton wool is often used to suggest clouds but I have a good collection of wooden balls.
So, with some sanding and gluing, I could make a cartoonish sort of cloud which was just right.
After a bit of painting, I used some 4 mm dowel to glue the cloud firmly to the rainbow. This meant that I could hold the cloud in a fixed attitude and could drill four parallel holes for the raindrops.
I then drilled matching holes in the base, as well as a hole up through the rainbow for the 4 mm dowel which holds the sun up in the sky.
For the movement, I used a piece of brass rod and bent it using pliers, sliding on some drilled 4 mm dowel pieces as bearings before adding the next bend. The four bearings are roughly at 0°, 90°, 180° and 270° so that each raindrop seems to move out of phase with the others.
You can see that the crankshaft also turns a wheel at the left. This wheel will friction drive the hemisphere attached to the bottom of the dowel holding the sun.
After adding bearings made of drilled pieces of dowel to the bottom of the raindrop rods, I attached linkage rods to the crankshaft before fitting it all together and fixing the ends into the bearings by adding a final bend.
To stop the bearings from slipping out of their respective brass loops, I then added a drop of two-component epoxy resin glue to the outside of each bearing.
Mistake 1 – Moving Holes
When I did my trial assembly I found that I had made the linkage rods too short and the mechanism jammed. Once I recognised the problem, I had to move the holes in the right hand side and in the internal partition down 10 mm. To move a hole, you fill the old hole with a suitably thin piece of dowel (first making the hole bigger if necessary) and then drill a new hole.
Mistake 2 – Cloud Too Thin
Once everything moved smoothly, I found that the rod for the right hand raindrops kept falling out of the cloud. When I made it longer, it then poked out of the top of the cloud on the up stroke. I thought about inflating that end of the cloud by the addition of a new ball, but then decided to add a small bird, calmly flying high up, towards the sun, thus keeping its feet nice and dry.
This was then a case of serendipity and not a mistake at all! Isn’t it fun just making things up as you go along!
Our princess had just been to the hairdressers which was so tiring that she settled down in a comfy chair in the garden and drifted off into a deep sleep. Meanwhile a sudden gust of wind in the treetops blew a new family out of the branches of a tree to drift down onto the lawn, tipping everyone out on the way. Well that new hairdo looked just right so it took no time at all to move everyone into this luxurious new abode.
And the moral of this story is – be careful where you nod off when you’ve just had your hair done!
What was the idea?
I was sketching a few figures in an idle attempt to move away from my usual style when my wife piped up and said that’s good.
As all dutiful husbands do, I agreed with her and knocked up a maquette in plastercine.
Some things changed a bit along the way. Now there are only 3 birds and the girl is now wearing stylish glasses. I took some photos and scaled the size of the printout to match the size of my piece of wood. Cutting out the figures from the printout allowed me to mark up my wood to prepare for cutting and carving.
I decided to make the birds move up and down as the handle is turned. This is the reverse of what goes on in an internal combustion engine for example. Instead of pistons moving up and down to cause some rotation, in this case the rotary movement causes the birds to move up and down, excited by the prospect of ma or pa bird returning with a juicy worm in their beak.
The unfortunate hostess for this pretty scene can do no more than wait patiently for calm to return, maybe tying a knot in her hanky to remind herself not to fall asleep again in the garden during the nesting season.
After marking up the wood, the first thing to do is to drill three holes for the birds to move in while things are still square enough for precision. The birds bodies are basically 10 mm diameter dowel so the holes are 11 mm to allow easy movement up and down.
Then the larger pieces of waste can be removed by sawing. Carving is much harder work than sawing so the more that you can remove like this the better.
It’s handy to refer to the plastercine maquette every now and again while carving and after a few days things will take on the required shape.
The base is a box with a crankshaft.
The crankshaft has three bearings at approximately 0 degrees, 120 degrees and 240 degrees. If you look from the end along the main shaft, you will see the three bearings (made from a piece of drilled dowel) evenly spaced around the shaft. I just bent a piece of 1.6 mm brass rod with a pair of pliers until it looked about right, fitting the wooden bearings as I went along. Once the rod is bent the bearings cannot be slid on, or off, which is just what we want; three reliable places to connect the birds with no risk of parts slipping out of place and jamming. The internal partitions are there to keep the crankshaft in place so that it can’t slip to the left or right..
The birds have to be painted before assembly in cheerful, birdy colours.
After positioning the birds with their cheeky beaks all pointing outwards, they have to be marked so that slots can be cut to fit a brass rod with a loop at the end into each slot. A pin pushed through the eye of each loop holds it in place. This arrangement prevents the birds from twisting around and poking one another with their beaks.
Note that to align the connecting rods to the wooden bearings on the crankshaft, I had to add a sideways offset to the yellow and green birds’ rods.
After checking for easy movement, I used epoxy resin to glue the connecting rods to the wooden bearings on the crankshaft.
I was amazed to find that with my hand-bent “crankshaft” the movement was very smooth, with little effort required. It is a very compact solution too. I didn’t carve the birds as they are comparatively small and the bright colours certainly catch your attention once they start moving about. Carving the main 12 cm tall figure took quite a bit of work, but I think it was worth it.
There is a range of small wooden figures widely offered for sale for young families with each figure sitting on a standardised piece of 17 mm diameter dowel. There is then a matching range of bases with 17.5 mm diameter holes into which the figures can be plugged. Apart from the plugging and unplugging, this is a very static affair so I decided to add some movement and open up a whole new world, to boldly go where no turkey has gone before. I also find that the commercially available, mass-produced figures are a bit too simple, restricted as they are by the low price that parents are traditionally willing to pay for them. I like to take a few hours to carve each small figure which presumably makes them commercially unviable, but hey, I make things for fun, not money.
A 15 cm plywood disc serves as the base. It has four supports for the lid and a central bearing which allows the vertical spindle to turn freely. Turning the crank rotates the drive wheel on which a disc rests which is attached to the vertical spindle. Friction means that when the drive wheel is turned, it causes the disc to turn, rotating the vertical spindle.
This very simple mechanism is extended by the addition of two wooden cogs. One is glued to the cranked shaft and the other is fixed to a small music box mechanism. This arrangement means that when the handle is cranked the wheel turns and the cogs also turn to produce a merry tune. The music box mechanism uses a ratchet to drive its music drum. Turned the “wrong” way, the ratchet simply clicks harmlessly now and then and no music is produced.
The vertical spindle is glued to a disc which is friction-driven round and round. The spindle passes freely through the middle of another 15 cm disc above which both a 67 mm hemisphere and sphere are fixed. The hemisphere is used to fix the arms holding the figures and, with a lick of paint, the sphere looks like our planet Earth.
The five arms are made of 8 mm dowel attached to 40 mm hemispheres with a 17.5 mm hole drilled in the centre. Stretch your imagination a little and these could be flying saucers.
This is a fairly simple carousel with music. The ability to change the passengers makes it more interactive, especially for kids who like to put their own slant on things. I can carve as many figures as I feel like as they can always form an orderly queue to wait for their turn for a ride. Apart from the five flying saucers there is also one prime position right on top of the world.
Terry’s a twirler An accomplished swirler A polished curler Magic with the ball He never lets it fall At all…
What was the brief and how did it change?
I started out with the idea of a dog chasing its tail on a small base. Having made a base with a crank to spin the turntable on the top, I then decided that the dog was a bit boring and that something more interesting was required.
A few pencil sketches later and I settled on a figure doing some sort of Victorian dance, with its arms diagonal making a more interesting movement as the turntable rotates.
Adding long rabbits ears emphasised the movement and a ball precariously perched on the top hand looks as if it might fly away at any moment. I’m not sure exactly what the result is but it was fun to make.
The parts for the base are mostly made of 3 mm plywood. The finished base is 55 wide x 55 deep x 43 mm high. The 15 mm diameter drive wheel and the 23 mm diameter turntable are made of 8 mm plywood. Using thick wood for the drive wheel increases the surface area in contact with the turntable thus providing more reliable operation.
The dowel serving as the axle for the turntable rotates freely in a bearing glued to the bottom of the base. A wider piece of dowel is glued to the axle to prevent it from being completely removed.
When these two pieces are glued together, the turntable can turn but cannot fall out.
The crank is made from a piece of bent brass rod and this is glued to the drive wheel using 2-component epoxy resin adhesive.
When the drive wheel is fitted, it lifts the turntable so that it no longer rests on the top piece of plywood but sits snugly on the drive wheel.
After checking that everything moves OK, the final side piece and the top can be glued in place. Two wooden spheres are fitted to the crank handle. The large ball turns freely while the small one is glued in place to prevent the large ball from falling off.
After carving and painting the figure, it can then be pinned onto the turntable with short pieces of 3 mm dowel and glued in place.
Recently aiming to make smaller pieces, I was pleased that it’s possible to make a comparatively small base with a reliable, crank-operated turntable. Although music boxes often feature a ballerina turning on tip-toe, I feel that just turning a figure without it “doing” anything else means that the figure has to be more interesting.
In 2021, I visited La Rochelle, an attractive seaside town on the Bay of Biscay in France. After a delicious lunch in one of the waterside restaurants, I popped into the Musée des Automates & Modèles Réduits (Museum of Automata and Scale Models – https://museeslarochelle.com) to take a look at their collection.
This museum opened to the public in 1984, with more than 30 years of work by the museum’s original creator, Michel Gaillard, to build up this collection. In addition to some prestigious antique pieces (for example made by Jouets et Automates Français (JAF), or Decamps …), there are some large animated displays. There are apparently more than 300 moving figures: mostly antique, with some animated window displays and historical scenes. I thought that I would share just a few impressions of what’s on offer.
Here is part of a reconstruction of the “Montmartre” district of Paris, which is used as a setting for some of the automata from the first part of the 20th century.
One of the shop windows shows a French butcher’s shop, with an automaton which I guess was used for advertising in the days before television took over the job. It reminded me of a modern work by Paul Spooner “Little Reinhold’s Wonderful Sausage Machine”.
It’s fun to speculate what this piece “Groom de service” made by JAF in 1923 was used for. I imagined it on the counter of a bar serving plates of salted snacks to keep the customers thirsty.
Of course there was a magician.
This work made me wonder a bit. It’s an automaton showing an automaton-maker at work. Its title loosely translates as “Vauconson making his famous mechanical duck. I took a quick peek in Wikipedia to find an article in French about a digesting or defecating automaton duck, created by Jacques de Vaucanson around 1734.
This clown balancing on a ladder together with a pig balancing a ladder on its nose, was made in 1895 by another famous automatist called Leopold Lambert. Follow this link https://mus-col.com/en/the-authors/10280/ for a short biography.
It was an interesting visit for me even though I know nothing about antique automata. The entrance fee also includes a visit to the adjacent museum which has a collection of model ships and a model railway setup.
The museum is within walking distance of La Rochelle town centre at 12-14 rue de la Désirée, 17000 La Rochelle
Other Automata Museums in France
If you search for “musée des automates”, you will find several matches in France.
I recently watched a friend brush her daughter’s teeth before putting her to bed and I wondered how rabbits set about this mundane task. I mean they have very visible teeth which they must be quite proud of and they can’t pop around to the shops to buy a toothbrush. I have never asked a rabbit, but I am guessing that they might use a bit of brushwood as they live a healthy outdoor life.
Two wooden eggs basically make up the rabbit’s body and its head. 3 mm plywood serves to make the teeth and ears. A piece of 5 mm dowel joins the rabbit’s head to its body.
A through hole, drilled sideways through the body, loosely accommodates a piece of 4 mm dowel to which the rabbit’s right arm will be attached. A slot cut in the rabbit’s back allows a brass lever to be inserted into the dowel to rotate it a little.
The angle of the arm to the body is important if our brushwood brush is to move correctly in front of the teeth so, before doing any carving, I checked that the angles were correct with a very rough arm.
Once the angles are OK, it’s safe to cut the arm roughly to shape before starting to carve.
The base is a simple rectangular block with a through hole from front to back for the crank to turn easily and a hole for some dowel to attach the rabbit to its base.
Once the rabbit was largely assembled I glued a piece of brass rod into the horizontal dowel to move the rabbit’s right arm up and down. Another piece of brass rod passes through the base and I bent this into a crank. When the crank is at the top of its movement, the arm is down, when the crank is at the bottom of its movement, the arm is up. A certain amount of experimentation is needed to get the crank dimensions just right.
If you look closely, you can see that I soldered a small washer onto the crank to keep the vertical linkage on the horizontal part of the crank and to prevent it from slipping down towards the base. A wooden ball glued in place prevents the linkage from slipping off backwards, away from the base. When painted white this suggests a bobtail for our rabbit.
The front part of the crank has two balls, a small one which is glued in place to retain the larger, free-turning ball. Grabbing this larger ball allows you to rotate the crank endlessly, without having to let go. The rabbit’s left arm doesn’t move and is glued in place, covering up the end of the hole containing the horizontal dowel. The toothbrush is a piece of dowel with two token leaves attached. This rabbit has long, rabbity feet but its legs are left to your imagination as an unnecessary complication.
The finished bunny is quite small, about 13 cm high and its mechanism is extremely easy to operate. Some of my larger creations can be quite stiff to use, especially for children. It was fairly quick to make apart from the carving. I enjoy taking my time when carving, making hands with fingers and thumbs always takes a while (my rabbit has fairly human hands). With no explanation, adults find it hard to understand what is going on here. I considered writing the title “How do rabbits brush their teeth” on the side for English-speaking adults but have decided against it. Mysteries are an interesting part of life.
I was poking around a museum shop in Denmark and I came across a splendid elephant designed by Kay Bojesen and made of oak. There are images of this classic product on the Rosendahl web site. I thought that it would be fun to have a go at making my own elephant with some interesting movement. My elephant would have to be able to pick things up with its trunk and of course it would have to be able to fly. I did think about Dumbo-style ears but on consideration I thought that was a bit far fetched. How can an elephant possibly fly by flapping its ears? Instead of that, my elephant has a very modern howdah strapped to its back which contains the mechanism to drive a high efficiency helicopter-like propeller. As usual, there is a crank protruding from the back of the howdah to get things moving.
The trunk should be rigid, operated by unkindly pulling our poor elephant’s tail. To help her to pick things up a magnet is required in the end of her trunk. The propellor should be friction driven to make it less likely that over enthusiastic admirers can break parts such as a pin wheel. This friction drive should work even if the elephant is up side down. We don’t want to risk a dangerous power loss during aerobatic manoeuvres.
Making the Elephant
The head is made from a wooden ball and the body from a wooden egg. Cutting a slice off of each part makes them fit nicely together.
A hole drilled through the head is as wide as the elephant’s trunk allows a string to pass through. A slim brass rod serves as a hinge for the trunk.
The trunk is carved from a piece of lime wood with a suitably drilled hole for the brass hinge rod.
The string emerges from the top of the trunk and another brass rod, near the bottom of the opening, makes sure that tugging the string results in a downward pull to make the trunk lift up.
A hole drilled straight through the elephant’s body allows the string to come out where the elephant’s tail will be.
Now we have to carve a pair of tusks and make a hat from a wooden cone which sits at a jaunty angle.
Use a template to cut two ears from 3 mm plywood, adding a slim strip of the same material to strengthen the simple glued bond to the head.
Now we have to carve four legs, two longer ones at the front and the shorter ones at the back.
Adjusting the legs to fit against a slightly tilted egg shape was a bit tricky. Trial and error got me there in the end.
I don’t have a sanding machine as I find the “tools” in the picture do the job for me. The larger tools have a velcro pad to hold suitable sanding papers which you can either use free hand or they can be clamped in a vice. The smaller ones are pieces of fairly rigid foam with pieces of sandpaper glued to the surface. Available in a variety of grades, these are great for smoothing elephant legs.
Making the howdah
Usually howdahs were put on elephants so that wealthy princes could ride around in style or in older, more disreputable, times go tiger hunting from a safe height. My howdah contains the mechanism to allow our pink elephant to fly around.
In the picture you can see three parts. The left hand part is the basic box with a small magnet glued in the bottom centre. The right hand part completes the box and carries a plywood wheel which is turned by a crank outside of the box. The centre part drops into the top of the box so that its wheel rests on the edge of the wheel which is turned by the crank.
Note that the vertical dowel which will turn the “helicopter blades” also has a magnet on its lower end. This is attracted to the other magnet and has the effect of pulling the horizontal wheel down onto the vertical wheel which is turned by the crank. Without this gravity would do a similar job, but only when the elephant is standing on a horizontal surface. Turn the elephant upside down and gravity would pull the wheels apart. The magnets also result in a stronger force than gravity provides, so there is a more reliable connection between the two wheels, while still permitting slip if a child try to turn things directly.
A strip of 3 mm ply above the horizontal wheel keeps the vertical dowel nicely perpendicular to the howdah, which now has some decorative sides added.
I carved a small banana and added a few steel tacks to it so that the magnet in the elephant’s trunk can pick it up. Some tape from my wife’s sewing box served as the belt to apparently hold the howdah on the elephant’s back. Some 3 mm dowels and a spot of glue do the actual work of holding it in place. The tail is made of a couple of wooden beads. I painted a mask on its face remembering a joke that my father told me a long time ago about an elephant who robbed a jewellery shop and the red toenails must come from a childhood joke about elephants hiding in cherry trees. I was interested to read that elephants have a differing number of toenails on their front and rear feet. My helicopter blades look rather like a flower, so I added a few leaves to the horizontal wheel in the base to make it more realistic.
The other day I came across a picture of a vintage Fisher Price Snoopy Sniffer toy dog to pull along. Fuzzy childhood memories surfaced of having once seen one of these in action, with its doleful eyes and slightly frantic leg movement. Of course I couldn’t resist having a go at producing my own version, with a handle to crank so that I could admire it in one place on a convenient table, instead of having to scamper around with my nose to the floor risking a hay fever attack from low-level dust mites.
I had always thought of this as a bloodhound, probably used every day by Sherlock Holmes pursuing his Victorian Villains through the wild English countryside. A deer-stalker hat was thus indispensable! As far as a Victorian Villain was concerned, I thought I would take a minimalist approach and just show his boots. Maybe Sherlock is after the invisible man, who unfortunately has to wear sensible boots to carry out his villainous deeds?
To keep Sherlock’s Snooper Sniffing dog in one place, its wheels run along a rotating, slightly irregular cam, to make the movement uneven and so more interesting. As this cam turns, a pin protruding from its face drives a rod backwards and forwards to which a boot is attached. A realistic walking movement would see the boots not just move forwards and backwards, but also up and down. I’m afraid that my minimalist, invisible villain rather drags his feet and doesn’t lift them at all. I made the boots free swinging and, if you scrunch your eyes almost closed, you can imagine that it could actually be someone walking.
The dog’s design
A super sensitive nose close to the ground and an expressive tail are vital accoutrements for our canine sleuth. On a more practical level, its paws have to be moved in a circular motion via the wheel inside the dog’s body. As the paws move, the leg attached to the paw flexes and the elbow moves up and down, moving in an arc relative to the shoulder pivot. I drew the highest position in red and the lowest in blue. This was helpful to check that the front and rear legs don’t collide. When I was satisfied with that, it was then easy to dismantle the drawing to show the parts.
Printed out on some stiffish card, these can be cut out as templates.
Use the templates to mark some plywood, drill the holes and cut the pieces. One tail, four paws and two of everything else.
Most parts are in 3 mm plywood. The wheels are 6 mm plywood, so the two halves have to be kept 8 mm apart by a spacer which has the same shape as the top section of the sides. This also leaves space for the tail to swing around a bit.
With judicious use of 3 mm dowel and some 6 mm hemispheres to cap the ends, the assembled dog looks something like this.
My original design for the base shows two identical cogs, each with 20 teeth. I used https://woodgears.ca/gear_cutting/template.html to produce and print their design, I glued them onto some 10 mm plywood and cut them out. But why, did I need cogs at all? As the slotted mechanism to move the boots, slides back and forth in front of the cam, it is not possible to simply extend the cam’s centre axle and fit a crank handle to its end. My solution to this problem is to use two cogs to effectively move the drive axis outside of the cam.
This is easier to understand from a picture taken from above the mechanism.
Here you can see 5 pillars made from 12 mm dowel. There is one pillar at each corner and one towards the centre. This centre pillar holds the short axle which joins the cam to the left-hand cog. As the crank is turned, it turns the right-hand cog which in turn drives the left-hand cog, making the cam rotate.
The left-hand cog also has a pin in its outer face to drive the second slide
As the cog is turned, its pin then moves the slide backwards and forwards, thus moving the boot.
So far there is no connection between the dog and the base so we need a hinge.
A piece of 4 mm dowel is fixed to part of the dog’s body where the moving legs can’t bump into it. This dowel can turn around axis B allowing the dog to tilt gently forward and back as the irregular cam turns. To make sure that both wheels stay in contact with the cam, rotation around axis A allows the dogs whole body to move gently up and down. This all means that the dog’s movement is more lively and interesting as it tracks the profile of the rotating cam. I chose not to restrict the rotation around axis A which means that the dog can swing wildly if you pick up the finished thing too impetuously. This may be a problem with children, but I’m sure adults will be more cautious. My dog did tend to loose contact with its rear wheel so I added a weight inside the body, above the rear wheel which fixed that problem nicely.
I didn’t intend to make it suitable for left-handed use, but that’s how it turned out. With the boots at the left-hand side you naturally want to hold the base with your right hand and then turn the crank with your left hand. I thought about putting the crank on the other side to make it right-handed, but then you would be looking at the side with the hinge and I preferred to avoid that.
Lucky lefties! But hey why ever not? When I build something for the first time I find that I can never think of everything in advance. My brain starts to hurt. After my day’s ration of decisions has been used up, I just wait with interest to see how things turn out.
My yoga practitioner rather likes to wear a star-studded top hat while doing the daily exercises. As the hat kept falling off while doing the traditional cross-legged leaps, it seemed more useful to drop the hopping about and to concentrate solely on levitating the headgear. This requires years of practice and only the most experienced can master this extremely advanced technique. The very best practitioners eventually achieve a state of wisdom manifested by an owl appearing beneath their topper. A red owl shows a counter-clockwise attitude to life whereas a green owl definitely reveals a clockwise sense of being. Just turn the handle and be amazed at what you can discover about yourself.
The Technical Brief
The mechanism is simply based on a very eccentric cam and a drive wheel on the same horizontal axis. These both friction-drive wheels attached to two coaxial vertical shafts, one hollow one not. The eccentric cam doesn’t just rotate its wheel, but lifts it up and down by 5 cm (the size of the owls). Its wheel is attached to the hat via a wooden dowel which turns loosely inside a brass tube. The other driven wheel is connected to the brass tube which passes freely through the figure and its other end is attached to the owls. This wheel must only turn through 180 degrees to show the correct coloured owl. As the biggest drive wheel is quite large, a largish base is needed to accommodate it. Making up more than one half of the whole assembly my feeling is that it then needs to be interesting in itself. To this end I chose a round base, a very open structure so that you can see everything that goes on, and I cut decorative holes in the drive wheel and cam.
The Sun Cam
The “sun” cam is mounted on the axis which is turned by the crank. It has to provide an up and down movement of 5 cm. I chose X to be 3 cm and Y to be 8 cm which gives the required difference of 5 cm. To add to the slightly mystic flavour of the piece I cut a sun pattern. The sun does go up and down after all and with a bit of yellow paint it does look quite sunny. Note that I didn’t paint the outside circumference of the cam as it rubs against the wheel which it drives and the abrasion would quickly wear the colour away.
The Star and Moon Wheel
The “star and moon” wheel to turn the owls around has to have a larger radius Z=9 than the cam’s largest radius Y=8. This is to allow space for the wheels which are friction-driven. As this is a nighttime pattern, I painted it dark blue which is a nice contrast to the “sun” cam.
The Wheel which turns the Owls
This wheel is glued to a brass tube. The other end of the tube is attached to the owls. To prevent this wheel from being turned by more than 180 degrees, I have inserted two pieces of 3 mm dowel which bump up against a piece of dowel which protrudes down beneath the top of the base.
Once the stop is reached, although the “sun” cam continues to turn, it now just slips on the wheel, until the crank is turned in the other direction which will then result in a reverse 180 degree turn.
The Wise Owls
This strange looking beast is a 5 cm tall owl, or rather 2 owls back-to-back. This is why it has 4 eyes and two beaks. The hole drilled vertically through it is a snug fit on the brass tube. Turning the crank clockwise turns the green owl to the front. Turning it counter-clockwise rotates it by 180 degrees to bring the red owl to the fore.
The figure has no moving parts, it is just a support for the owls and its hat with a vertical hole all of the way through which allows the brass tube to turn freely. I went for simple crossed arms and legs, which is my version of the correct pose for yogic flying. The figure is as short-sighted as I am, so of course it needs a pair of spectacles. The top ring serves as a nest for the owls.
I needed thin walls for the hat, so that the owls have space to do their turns. An old plastic tube was just the right size, if a bit of a nuisance to paint, but I managed to find some suitable black gloss paint for a starry night. This also turned out to be so lightweight, that it would go nicely up but would then hesitate about coming down. A lead weight right at the top fixed that while leaving space for the owls.
The Drive Shaft for the Hat
The thin part of the shaft runs inside the brass tube and is attached to the top of the hat after passing through the owls. The thicker part rests loosely in a hole drilled in some 25 mm dowel which is fixed to the bottom part of the base. It was OK to paint the outer circumference of the driven discs as they don’t touch anything. Using a strong pattern makes the movement very clear.
The base is quite large owing to the need for a simple cam to produce 5 cm of vertical movement. I toyed with the idea of using a lever to multiply the cam’s movement, but without the rotation it would then not have been possible to magically change between red and green owls. There is probably a more complex solution which would do what is required in less space, but everyone wants to see how the mechanism works anyway, so having everything out in the open and brightly coloured makes it all a part of the show.
The other day I came across a video of Peter Markey’s wonderful “Cyclist” (see http://www.contemporaryautomata.com/videos/cyclist/index.html) and I liked the movement. Not only does the small figure pedal madly like a child on a tricycle, but the road goes up and down, making the bicycle tilt forwards and backwards. “I’ll have a go at that,” I thought and mentally added a small change to the figure’s head to allow it to also swing about, adding quite a bit more movement.
Instead of setting off straight into the workshop, I thought for a change that I would try drawing my design in some detail and in doing so make it easy to print out templates which I could trace around on sheets of plywood ready for cutting.
I used a drawing application called Graphic for Mac. This has layers, so that I could draw each part on a separate layer, rather like layers of plywood. It’s not expensive 3D software, so I couldn’t do a full design at my desk, but I could check out basic things such as checking that the knees do not bump into the handlebars while pedalling.
I chose to use a landscape with 3 green hills. The front and back hills are fixed and provide a framework to hold the axle for the crank as well as a tilting support for the bicycle. The middle hill isn’t really a hill at all but a rotating cam with ups and downs to make the ride more interesting. A rolling landscape.
Cause and action are reversed here. Turning the crank moves the road, which turns the wheels, which make the feet move. The viewer however gets the impression that the figure’s legs are pumping making the wheels turn etc.
Cutting spokes is an unnecessary complication. I thought it would be quite OK to leave the wheels solid and just paint the spokes, following Peter Markey’s example.
To make the head swing free, it is made up of two parts which are joined at the top by a piece of brass rod. Trial and error tells you where to drill the pivot holes and small wooden hemispheres on each side serve both as a flower in the girl’s hair as well as increasing the surface area to which the brass rod is glued thus making a stronger joint.
Having drawn all of the shapes with a computer it was easy to to print out the individual shapes on some card, which I then cut out with scissors to make a set of templates. My bowsaw made short work of cutting out the bike from 3 mm plywood and the wheels and hills from 6 mm plywood. The centre part of the body determines the spacing between the two halves of the bicycle frame, so it has to be a little thicker than the wheels to allow them to rotate freely. The joints are made with 3 mm dowel.
It was only sensible to paint the parts as far as possible before assembling the figure and her bike.
The joints in the legs use 3 mm dowel. To ensure free movement, the hole in the moving part is 3.5 mm and a small wooden hemisphere on the end of the dowel prevents everything from falling to pieces when the pace picks up.
Once I had provisionally assembled the cyclist and had checked that she pedals nicely when rolled along the workbench it was time to consider how to attach the bike to the landscape.
As the shape of the cam on which the wheels run is not a regular circle, the bike has to be able to tilt forwards and back when cycling downhill and uphill to maintain contact with the road. A piece of dowel glued to the base of the bike can rotate in a hole drilled in the rear hill. A certain amount of up and down movement is also needed to keep the wheels on the road. I had thought of making a fairly complex pivot to allow this, but it turned out to be unnecessary. The play between the dowel and the hole in the rear hill was enough to keep everything moving.
The lever that you use to wind an automata into movement is often boring, so on a whim I went for a leaf shape, as everything was so pleasantly green. You can play with the words here as in “Turn over a new leaf and go for a ride on your bike”. It amuses me, even if most of my German friends look completely blank. I usually make the part that you grab hold of red as a signal – “start here”.
Also something is required to keep the front and rear hills parallel to one another and I started with a boring rectangle. Imagining myself cycling through the hills of sunny Italy I thought let’s have a tunnel instead. Italians are master tunnel builders, which is handy given how many hills they’ve got.
Have you ever thought how you can make hair move? Inspired, as so often, by an image from the Internet, I wondered first of all how to make triangles hanging from the circumference of a head stand up. It seemed pretty complex to me and I wasn’t sure that the result would be worth the effort. Then I noticed that I still had a few bases for thumb push puppets lying around so I decided to stretch the concept a little of what hair looks like.
This is fundamentally a fairly simple project and the idea is that when you pick the figure up and press its base the hair should move. A standard thumb push puppet has one spring in the base and four strings attached to a disc on the bottom of the spring. Having only four strands of hair seemed a bit thin to me so I went for eight instead.
There is however a reason why four is the standard number and I guess that it has to do with keeping the tension about the same for all of the strings, when no one is pushing the base up. The spring permits the disc in the base to tilt in any direction, thus compensating for some of the differences in tension at four points on the circumference. Having eight points around the circumference might bring the points too close together for tilting to effectively correct for differences in tension. My quick fix for this is only use four points but, instead of fixing each string to the point, I arranged for a smooth anchor bar around which each string can slide thus allowing both ends of each piece of string to be used up on the figure’s head. If the friction is low, the tension at the two ends will be very similar. This results in eight ends to play with and the tilting of the disc can compensate for slight differences in tension as usual.
The base needs eight holes for the four pieces of string. The figure’s dress will cover the four old, unused holes.
I modified the original disc which fits into the base by cutting four notches and gluing a piece of bent brass rod on top with epoxy resin adhesive. This arrangement leaves plenty of space for each string to slide easily.
The head is a 40 mm diameter beechwood ball predrilled with an 8 mm through hole. Slid onto a slanted piece of 8 mm dowel this can be rotated to drill eight holes which are suitably spaced for hair at the top, but which are slanted so as to come together at the neck hole.
The figure’s body is a beechwood cone with the tip cut off and a through hole, widened at the bottom with carving tools. The strings come out of the holes in the base, pass through the conical body, out of the neck hole and into the head, where each string has its own hole from the neck up onto the top of the head.
Before the final assembly, the parts have to be painted.
I used masking tape and a block of round wood to press and hold the disc up, compressing the spring a little and holding it in place while the strings are threaded up through the figure.
I used kite-flying string as it is both flexible and strong. Patience is required while threading, but using long strings helps. Five small brown balls go on each string and the last one to go on is then glued in place after closing the hole with a tiny piece of dowel which also jams the string as it is pushed in. It’s important to tension of all eight strands of “hair” about the same, so that they all stand up when the spring is released. If one string is less tense than the others, two strands of hair will flop down and spoil the effect. It took me three goes and much gnashing of teeth to get this right.
I almost added arms to the conical body but decided they would just make it harder to hold and operate, so I painted them instead.
For the video I borrowed the story from a well-known English nursery rhyme. https://www.youtube.com/watch?v=fB6XfBY2um8
Little Miss Muffet Sat on a tuffet, Eating her curds and whey; There came a big spider, Who sat down beside her And frightened Miss Muffet away.
I have no idea what a tuffet is. In my case it’s obviously blue, whatever it is. In retrospect my thumb puppet could have been a cranked automaton where a spider appearing causes her hair to stand on end. Some other day perhaps.
Some while ago I enjoyed a video produced by an Italian artist Giuseppe Ragazzini (https://www.youtube.com/watch?v=VurUCgxdp8E) and I thought it would be fun to make my own real world, wooden version which doesn’t need an internet connection. Then a friend gave me some doll’s eyes, the sort of eyes which close when a doll is put to sleep. That was enough to finally get me started on the Bizarre Belle of the Ball.
I chose to have 8 sets of eyes mounted on one disc, 8 noses on a second disc and 8 mouths on a third disc which is enough for 512 distinct faces so that our belle can go to 512 balls and never have to look the same twice.
To frame each face and concentrate the viewer’s attention on it, it seemed best to use our bizarre belle’s arms. Whenever her eyes are correctly aligned, both arms should come up. To make it a more convincing gesture, she should hold a mirror in one hand to admire the finished effect and a comb in the other to tidy her non existent hair. One turn of each control knob should rotate the disc through exactly one eighth of a turn.
The smallest 3 mm plywood disc is attached to a solid 6 mm axle. This axle runs inside a thicker hollow axle for the middle-sized disc. The largest diameter disc turns around both with several spacers joining the disc to its cog while leaving room for the doll’s eyes.
If that sounds complicated, here is a section through the middle. This means you are looking at these discs from the side
To make the 3 discs turn, you then need 3 large cogs behind them.
Small cogs will drive the big ones, so the number of teeth is important to set the speed of rotation of each disc. With 8 noses etc., the number of teeth on the big cogs must be 8 times the number of teeth on the small cogs, so that one turn of the control by the user moves from one nose to the next. I chose 7 teeth for the small cogs which then means 56 teeth for the big cogs. I find that cogs with small numbers of teeth can jam easily and 7 is actually quite close to the limit.
To shape the cogs I used Matthias’ splendid online gear template generator https://woodgears.ca/gear_cutting/template.html. To save time and work here, I first pinned three sheets of 6 mm plywood together, glued the template on top and then cut the three large cogs at once with my scroll saw.
Body and legs
To hold the rotating discs and cogs some sort of frame is required. A dress with a wavy frill at the bottom and a round upper body seemed about right. Two legs would be a bit unstable, so my bizarre belle has four legs. The front part also has to take the mechanism to lift the arms up. Some elegant carved shoes are, of course, needed to equip our belle for the ball.
The hole between the legs takes an axle fitted with an eccentric cam. As the axle is turned the cam presses the vertical actuator down, which pulls the arms up. The loose round part at the top is the lid to keep all of the parts in place and it also has a hole in the middle which serves as the bearing for the axle for the rotating assembly.
The rear part of the body carries 6 small cogs, 2 for each large cog. They are each set at the correct height to drive their own large cog and hence the corresponding disc with noses (left) eyes (centre) and mouths (right). Each knob on the front of the figure turns an axle which turns one of the small cogs. The reason for the second, identical cog is to provide enough space for the hats on the largest dic to move unimpeded. As the two cogs are identical there is no change to the transmission ratio and one turn of the knob will still move its disc through one eighth of a turn.
Putting the parts together after carving eight noses, our bizarre belle starts to take shape. I was surprised to see that, when near horizontal, the doll’s eyes close and open one at a time, as if they are winking at me. Only having four sets of doll’s eyes, I improvised eyes for the other four faces.
I had originally planned to use three cranks in front of the dress to turn the parts, which would have meant putting the figure on a heavy base. I find that on the up-stroke when turning a crank, models tend to skitter around unless they are heavy enough or have a non-slip coating underneath. By changing to spherical knobs, which you have to twist to operate, the upward force disappears and with it the need for a base. Magic!
It is easiest to understand the mechanisms when you can see them in action so here is our belle of the ball deciding how to look for her next ball. https://www.youtube.com/watch?v=gMLE70_scGE
Recently I was playing around with an augmented reality robot on my mobile phone https://developer.apple.com/augmented-reality/quick-look/ (it doesn’t do much on a desktop computer). After a while of course you get fed up with virtual stuff and I thought that it would be more fun to make a tangible desktop robot with parts that really move.
I wanted something friendly that wasn’t too complicated and something which initially looks like nothing special but which you can discover by pushing bits to see what happens. Best would be something to make you smile as things start to move. A sort of stringless desktop puppet, which reminded me that I always wanted to have a go at a pinocchio puppet with an extensible nose for when it starts telling lies. The hands should be useful but, for simplicity’s sake, should not have too many fingers so a spanner shape seemed just right. To make the nose extend, I made Blubot’s top tilt around its centre line, and a rod attached to the back of the top yields enough of a push to make the nose stick out. I even did a simple drawing to check that it would move far enough.
Drawing to check the clearance for the eyes and the movement of the nose
This is basically a 10 x 10 x 8 cm box. The parts are cut from 10 mm plywood with a saw or a scroll saw for the curved bits. Good quality plywood means that the individual layers are properly glued and cutting doesn’t cause too much splintering.
Parts for the box
The nose is a piece of 12 mm diameter dowel in a 13 mm hole. It was then handy to use a piece of the same 12 mm dowel to fix the nose linkage to the hinged lid. The linkage is a piece of 1.6 mm brass rod.
Top part of the box with eyes and nose
The nose linkage
I painted the eyes before gluing them in place and I glued a row of small hemispheres along both sides to make a sort of rivety impression.
Initial version of Blubot
Addition to the design
At this point I painted all of it and tried it out on my four-year old test pilot. More or less her first comment was that it has no legs. I had originally thought that legs wouldn’t add much to the narrative and might destabilise things. On reflection, I thought, OK well let’s add something moveable to the legs and decided on child-safe rocket flames, which come out on lift off. They just dangle on the string and disappear when you place the model on a flat surface, sliding back up into the legs.
Making the legs and feet
For the feet, I used MDF, drilled a hole for the flame, used a bowsaw to cut a round shape and then sanded a taper. Continuing the rivet theme, I added 4 hemispheres to each foot which then look like toes, elephant’s toes!
The flame (right) slides out of the leg (left) and is retained by the string
I thus added three chunky legs, each with a hole drilled through the centre to accommodate the flames, each made of a piece of suitably shaped and painted dowel. Add a piece of string to prevent the flames from completely falling out and Bob’s your uncle!
It was good to work with better quality plywood than I sometimes do and I was very pleased with my simple wooden hinge at the back of the box. I generally find working with brass hinges quite hard work in such small items. Also, tilting the lid with two fingers to reveal the eyes and extend the nose gives you a very good level of control. Just right for puppeteering!
I find that the longer something takes, the more ideas that you have, don’t you? Even when you are painting, things can occur to you and it was only while painting that I thought of rivets for the eyebrows. 3D rivets were no good, as the lid wouldn’t close so I opted for nice painted red dots instead, which are the very first things to appear as you start tilting the lid. Almost the last things to appear are the two goofy teeth which is quite a funny climax to the opening of the box. I had originally planned on a full set of teeth, changing my mind at the last instant.
The flaming legs were quite simply an afterthought. It’s hard to imagine everything in your head right at the beginning. As things come together in reality, it is then easier to think a bit further and to grow your original idea.
Happiness is infectious, so a happy couple must be doubly infectious, no bad thing to catch whatever else might be going around. The challenge is to move a happy couple into the fourth dimension so that they aren’t just in a happy state, they must also move happily too. I thought back to one of the United Kingdom’s prime ministers, Edward Heath, who was renowned for his heaving shoulders when he laughed, copied by many, not least by a later prime minister Theresa May (see https://www.youtube.com/watch?v=U_wGgPvoysQ).
Our happy couple are also confronted with the eternal question of what to do with your hands whilst on the podium. I decided to have the woman hold a cheerful bunch of flowers, in her personal colour scheme. For the man, another, smaller happy couple seemed just right, even if children have their own ideas about when to be happy or not.
My test engineer, a very smart 4 year old girl is so entranced by talking figures that she likes to not just follow the programme set by the cams, she likes to improvise too, inventing her own narrative about what is happening. This often means grabbing brass rods and yanking them to achieve her desired effect. In this automaton I thought that it might be smart to anticipate that and offer two ways to bring our cameo scene to life. A red handle turned on the side gets the cams moving stubbornly through their preprogrammed sequence and blue and green levers on the front allow free improvisation.
With the blue lever, the man can chatter or laugh endlessly, while his partner waits patiently. With the green lever the woman can return the compliment, while he listens attentively. Of course both can join in the action as and when they wish.
This means that a logical OR function is needed. The shoulders lift and the mouth opens if the red lever is turned OR if one of the blue of green levers is pressed. This means that if the red lever has opened a mouth, pressing the corresponding blue or green lever will have no effect. Blue or green can only do their thing if the red lever is in a passive position which would leave the corresponding mouth closed.
Cranking the red lever turns two cams, one with eight regularly spaced movements, the other with nine. This means that the two figures laugh together, but they are not synchronous, making a pleasantly chaotic impression.
The heads are made from hardwood (beech) eggs which are cut through diagonally at a smiley sort of angle. There are a few tips for a successful cut. (1) It’s tricky to clamp an egg and then cut through it, so it helps if you first drill a hole in the end of the egg and then glue in a dowel. Now you can clamp the dowel, leaving the egg freely accessible for your saw. (2) My drill press produces two sparkly red laser lines which cross to show the position of the centre of the drill bit. If your drill has this feature too, it’s very handy to mark a “straight” line on an egg for cutting. (3) Drill the hole for the jaw hinge before cutting.
How to mark & cut hardwood eggs
The figures’ movement
The two figures’ movement is controlled in the same way. In this simplified section through the woman’s lower body you can see that one leg is fixed to the body (and to the base). The other leg moves up and down, which is not obvious to the casual viewer, pushing the waist and the upper body up and then allowing it to fall down.
Simplified section through the women’s lower body
The top of each head is attached by a brass rod to the lower part of the body. When the waist is pushed up this cause the rod to pull the mouth open. I used an old leather shoelace for the shoulder, elbow and wrist joints, allowing them to move quite freely.
Leather shoelace for the joints
Top of head is attached by a brass rod to the lower part of the body
The works inside the box
Turning the red handle rotates a small cog which drives a larger cog. This gearing makes it easy to turn and the outside lever is as long as possible to provide the best “leverage”. The larger cog is attached to the same shaft as the two cams which each drive a simple cam follower.
The geared drive for the cam with 8 curves. The other cam has 9 curves.
Pressing the blue or the green lever simply lifts one of the cam followers. At rest, the weight of the inside parts moves the outside knobs up into their inactive positions.
The blue and green levers
With slots cut in the front panel to allow the levers to move, the complete mechanism looks like this. Now you can see that each cam follower can either be lifted by the turning cam OR by pressing the lever at the front of the box (at the right in the picture).
The complete mechanism with two alternative ways to lift each cam follower
Note that if the cams are lifting the followers, then the blue and green levers will have little if any effect. You can’t lift something that has already been lifted.
I painted the parts for the figures prior to assembly and allowed them to dry properly to ensure that I got the clearances right for easy movement. The babies are very simply made and don’t move, their tiny fists and feet represented by small spheres.
There was an old spider who lived in quite a stew.
She had so many children, she didn’t know what to do.
So she span a nice roundabout from silken thread;
And whizzed them all around until she put them to bed.
Mum spider was worried about the kids just hanging about and wondered what she could do to keep them busy.
Then she saw this bare tree and thought this will do nicely.
With a little bit of work, there’ll be room for everyone.
The technical brief
The mechanism to turn the roundabout should be as simple as possible and should also drive a small music box mechanism which plays “Die Berliner Luft” – a tune that every Berliner knows about Berlin’s fantastic air. Spiders can have phenomenally large families, but I decided to go for a token number of nine baby spiders. What was good enough for Queen Victoria and Prince Albert is good enough for me. They had four boys and five girls, I will leave it to the viewer to decide on the sex of the various members of my little family. Brass rods will be strong enough to make the web and wood will do for the rest.
Making the family
The parts to make a baby spider
Baby spiders are uncomplicated creatures made of a small drilled wooden ball for the body, two wooden hemispheres for big appealing eyes and eight pieces of bent brass rod for the legs. For the strand of web for them to dangle from, I used a cotton thread glued into the predrilled hole which I then filled with a piece of 3 mm dowel.
Finished baby spider waiting for its colour
Fashion-conscious mum spider
Mum spider is larger of course, has a more stylish hairdo and shoes and a 3 mm hole in her underside to attach her to the top of the tree.
Spider mum and her freshly spun web
As there are nine spider children, the web has to have 9 segments. Mum spider needed a bit of help to make the web so I used slim brass rods, bent carefully to shape which I then soldered together, arranging for a slight “umbrella” shape. The web is mounted into a wooden ball which just rests on top of the tree, with a 3 mm dowel through the middle to hold mum spider, glued safely in position. As the ball is not glued, it is turned by friction. This allows mum to jig around and issue instructions to her brood and also allows the web to coast gracefully to a stop when the tree stops turning.
The base mechanism
The bare mechanism
On a circular base, I mounted the small music box mechanism which I bought for a few euros. After cutting its bent metal handle off, I could push on a wooden cog which I cut using my bow saw. An identical cog drives it, when the handle is turned. Fortunately the music mechanism doesn’t mind if you turn it the wrong way, it just goes click, click instead of playing its merry tune. Turning the handle also rotates the drive wheel which is in frictional contact with the larger wheel glued to the vertical “tree”. I added a wooden bearing at the base of the tree which, together with the hole in the upper part of the base, keeps the tree nicely vertical.
The assembled roundabout, ready for testing
The upper part of the base rests on three fairly chunky pieces of dowel. Careful alignment is required to ensure free rotation of the tree before gluing things together.