Making a special
screwdriver for the lab
During my lab experiments, sometimes I need to unscrew very tight screws. In these cases, I usually find myself in the embarrassing situation of having long lasting wrist pains, due to the force that I need to apply to the screwdriver. When the screw cap is not hexagonal or star-shaped, the situation becomes even worse, as I additionally need to hardly press the screwdriver downwards, to keep it firm on the screw that needs to be unscrewed.
If the screw cap is hexagonal or star-shaped, there are lever-shaped (Allen) keys that allow you to unscrew them without applying much force from your wrist. These tools do come in different sizes, one for each screw cap size. If the screw cap is different, you have to use the appropriate screw, or a screwdriver that can fit multiple screw heads. The later is a good approach, as you do not need to carry multiple tools, but just one tool and many smaller screw heads. Furthermore, if the tool head is damaged, you can replace it with another one easily.
Such screwdrivers have two main disadvantages though:
They do not have a lever mechanism. All the force is applied by your wrist, resulting in injuries on weaken wrists.
They use just a magnet to hold the screw head in place, which magnetizes the head itself (desirable in some situations) and results in a non stable head on the screwdriver tool.
Electrical screwdrivers are a possible solution too but they suffer from several disadvantages:
They are too big, not suitable for accessing screws in difficult areas.
They need charging. How many times does it happen that you want to use a device that is uncharged?
Much downwards force must still be applied from your wrists.
Most of them, are not powerful enough to unscrew very tight screws.
They start very rapidly. In many cases this results in damaging the screw cap or the screw head tool.
Good ones cost too much.
To overcome all these advantages, I have decided to make a special screwdriver tool. The preliminary design is shown below.
To be continued...
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