Cycling is about staying fit and using resources wisely.
Recumbent bike makers can even reuse old bike parts to make new machines – its
been very satisfying for me since about 1987!
Recently I’ve branched out to use old bike wheels in non-recumbent
things.
I have a 3D printer and a few years ago developed some
designs to join CDs together to make
geometric shapes (see article here). CDs are round just like bike wheels, and
so I've gone on to use CD joining techniques to make bike wheel versions of the
mathematical shapes called platonic solids. These include tetrahedrons and
dodecahedrons and I am working on a 20 sided icosahedron.
Inspiration for the shapes comes from the bike dome at Ceres
in suburban Brunswick– I don’t anticipate building anything that big and my
designs might be a bit more orderly, but the dome shows what can be done. The
Trisled newsletter recently featured a similar community-built dome at Meeniyan
in Eastern Victoria.
A few weeks ago, I gave my small tetrahedron table away to
my friend Simon for his 60th birthday and was able to transport it to his place
by bike. That was on the way to the Wecycle bike shed where we volunteer. At
his party later that evening, it was set up in his garden, staked to the ground
as its base is not very big and its prone to tipping.
A larger tetrahedron I made uses a raft of 3 bike wheels
bolted together to form a side of the 4 sided tetrahedron. I’ve had this for
quite a while and have transported it by trike and trailer. I’m not sure if it
qualifies as a road train or pantechnicon, but this is a 14 wheeled vehicle!
 |
| From Heidi "Here That’s a fun story – made me chuckle. Here’s a pic from the day.
Thanks for letting me use the sculpture!
Cheers
Heidi |
Once I took it to a community bike day and it was noticed by
Heidi Marfurt who is the Darebin Council’s sustainable transport officer. Just
a few weeks ago Heidi wanted to use the sculpture at another community bike
day, The Rezza Bike Day.
The sculpture uses the wheel centres as axles for small
windmills which also use cds as blades and a 3d printed hub. That is just a fun
thing but shows what can be done with recycling. When Heidi asked me to loan
the bike sculpture I decided to extend it and worked out I could make something
quite high (about 1.8m) without using only 6 extra bike wheels. The pattern is shown in the picture – as long
as there is part of a wheel on an edge, then the outer triangle shape can be
made, even if the outer triangle is not completely filled in. I needed 2 goes
of putting it together to get the pattern right.
Actually loading the sculpture sides into the Heidi’s car
involved Tetris-like manipulative skills and in the end only the smaller
tetrahedron would fit in. A few days later Heidi came back to my house with the
sculptures and they were festooned with ribbons and a couple of the CDs had
broken off. I was thinking it's a bit like those stories where a garden gnome
gets kidnapped and sends postcards from Queensland and then turns up months
later with a suntan and tattoos! Heidi was quite sick of loading and unloading
the sculpture in cars by this time, but the whole event went well and the
sculpture was appreciated.
Most recently, I used the frame for painting a crank arm on
a Wecycle repair bike. This was to turn a silver right hand crank black, as the
original black one had a stripped thread. The other hanger in the back yard is
the dodecahedron, used as my regular clothes line.
Sofar I’ve been making wheel joiners (they act as platonic
solid edges) from steel tube, pvc pipe or wooden dowel. When there’s a narrow
angle (ie on tetrahedrons), the large steel tube seems better, and the drilling
can be marked out with dividers and a centre punch. For larger angles like on a
dodecahedron, I use the dowel, and drill with the help of a 3d printed jig.
This wikepedia page
https://en.wikipedia.org/wiki/Table_of_polyhedron_dihedral_angles gives the
relevant angle between faces, it is called dihedral angle in geometry-speak.
I plan to go on building the bike wheel sculptures, and
mostly use 27 inch steel bike wheels. The 27 inch bikes are now of an age with
the are often being thrown out and are not worth restoring - or are only worth restoring if the wheels are swapped out - so they end up in
the recycling dumpster at Ceres. I can load up about 4 wheels at a time on the
back of my bike, even more if the spokes have been removed. Also I know Serge,
the volunteer who does most of the stripping of unwanted bikes at Ceres. We
stop and have a chat while I’m there, and swap notes about the Wecycle and
Ceres Sheds and our bikes.
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