WARNING: This model is very fragile. It is easy
to break accidentally, please handle it with care and read the instructions
below on how to cut the bikes out of the protection structure.
Expect to break several bikes while cleaning, cutting and
painting. Clean breaks can be glued back together with a small
amount of super glue.
The bikes are very small and can be difficult to find when dropped. Store them in a container with lid to avoid loosing them.
Here you can see some pictures of the bike in unpainted, orange, green and
blue frame. To give you an idea about the size: they are all standing on
double side adhesive tape onto an euro cent coint.
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General info on the materials used |
The material for all my models is called Frosted Ultra Detail
by
shapeways.
It is printed in a process called Multijet Modeling (MJM). The model is
printed in layers which are hardened by UV light. There is also a wax like
material used as support material. Most of it is removed directly after
print, but on some models it is stuck inside the holes and has to be
removed before assembly.
At room temperature the
Frosted Ultra Detail
is inflexible and breaks suddenly without
warning. Thinner parts break off very easily, so please handle all models with
care. It gets more flexible when heated, but still breaks suddenly without
prior warning. It is possible to very carefully bend it into a new position
while warm. The
Frosted Ultra Detail
will retain this position when cooled, but when warmed
again it will bend back to its original position.
The material can be cut with a sharp knife. Often small splinters will break off at the bottom of the cut. It is possible to smoothen the surface by sanding, I usually use a nail file.
The
Frosted Ultra Detail
material can be glued together with all-purpose glue and with
super glue. As super glue I prefer the liquid one since it sets so fast. I use
it mostly on parts which I fix in position before gluing. For stuff that needs
adjusting before the glue has hardened I use all-purpose glue.
For painting the
Frosted Ultra Detail
material
shapeways
recommends acrylic paints. There
are some reports in the user forums where models in
Frosted Ultra Detail
started to melt and
smell when painted with non-acrylic paints, so I decided to follow the
recommendation to be on the safe side.
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Cleaning Frosted Ultra Detail |
To remove traces of the support wax and the oil which is used to remove
the wax on the Frosted Ultra Detail
material I use a small
ultrasonic bath filled with water and a drop of dishwashing detergent. I
usually put the models in for 30 minutes with a change of water after
20 minutes when necessary.
Sometimes there is a white powdery stuff on some parts of the surface. This seems to be a mix of the support wax and the material. As far as I know the only way to remove it is by sanding or scraping it off.
To avoid damage while printing, shipping and cleaning, the bikes are contained inside a protection structure. Each bike has to be cut away from this structure. The remains of this structure left on the bike have to be sanded or filed away. The bike is very fragile and breaks easily. To minimize damage I use the process explained in the following paragraphs.
The points most likely to snap are the handlebars and the front wheel. When holding the bikes please hold them by the back wheel or the frame.
I do all the cleaning with everything still together, the protection structure should prevent damage while in the ultrasonic bath and while carefully rinsing the model.
Remove the bottom (dark blue in the picture) by cutting at the border with
a sharp hobby knife (cut at the red discs in the picture).
Now you can cut one bike free from the structure by cutting through the
two support struts with a small wire cutter. Do not try to cut them too
close to the bike, you may damage it.
For the next step I glue the bike with a small amount of hot melt glue onto a flat surface with a straight border (old 386 processor). This secures the bike while removing the rest of the struts. Carefully cut and sand away the remaining support structure.
Double sided adhesive tape does not work here, the
surface of the bike is too small to hold the front wheel, it breaks off.
To remove the bike for painting dissolve the hot melt glue with isopropylic
alcohol or methylated spirits. Add the alcohol, wait a bit and then
carefully pick up the bike with small pliers, it should come loose with
nearly no force. When it still sticks, add more alcohol and be patient.
Painting the bikes is challenging, they are very small and only look
good when painted in several colors. I use one glossy color for the frame,
matte black for the wheels, saddle and handlebar ends and silver for the
rest of the handlebars and the lamp front. Painting is an iterative
process, if you accidentally touch something with the wrong color you have
to paint it over again with the right color. With a bit of patience the
bike looks better after each step.
