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.
Youtube link https://www.youtube.com/watch?v=kT8DVzUdK0E
Download images here https://www.wordwise.de/Happy_cyclist_mages.zip