This microscope was simple to build once I had
finalised my design. The most difficult part of the design process was
deciding how my microscope would be focussed. I had worked on a design
in which the barrel had moved while the stage remained stationary,
using a somewhat complex pulley system.
Another focussing system which I considered was a
lever used to push the stage up. I decided against this system because
of the resulting instability of the stage.
In summary, after trying various systems
involving a pulley, lever, or wind on cable, I settled for the screw
My current design gives a reasonable level of
stage stability and it is physically impossible to ram the objective
through a slide. This is a major advantage over other microscopes due
to the shape of the screw.
Because it runs on battery there is no danger
of electrocution or tripping over cords. This makes it safe to use
around small children, who would usually miss out on the experience of
using a microscope.
Using a 3 volt button cell, the ultrabright LED
is not bright enough to blind, eliminating the need for a mirror and
sunlight. Unlike a bulb, the LED does not give off heat, thus the cell
should last quite a while.
My microscope has few components, making it
ideal for light transportation and easy storage, and also reduces the
difficulty for the user.
Users will not be required to change objective
lens, a process which can confuse some people, and in a traditional
microscope can lead to the misuse of the oil immersion lenses, which
are not required for most samples.
It is possible to change the objective lens
relatively easily if necessary.
In finding the right way in which to position the
eyepiece and objective lenses, I learnt that it was not critical to
have the barrel exactly 170mm, which is a positive thing as it allows
room for error.
My microscope magnifies the image 150X. I obtained
this number by multiplying the value of the eye lens, 15X, with the
objective lens, 10X. This is a good value for samples for junior
students (i.e., crystals, fibres, plant cells, protozoa).
However, I would like to further improve my
microscope with the addition of a proper switch and battery holder.
While my current power system has the advantage of the cell being
easily removed and changed, I would like to make it more permanent. I
would also like to improve the slide clips, which currently have
difficulty moving due to obstructions. I have no mode of moving slides
other than by hand and this could be something I will include in my