4:00 PM - 4:15 PM
[G03-09] Thin-Section Making Recipe in a classroom Ver3.0 -using 3D printer-
Keywords:thin-section, rock-saw, rock-grinder, polarized unit, geoscience education
We have been developing the method to make and observe rock thin-sections easily at a secondary school classroom. Our previous method is necessary to make some parts using a lathe-machine and employ metal processing skills. This process is quite challenging to realize in a standard school. Therefore, at this conference, we will present a new approach to promote the above purpose using plastic parts made by employing a 3D-printer as alternatives to metal parts, which is very popular in science rooms at secondary schools.
The base tools are not changed 1) Homemade rock saw employing a bench-grinder, 2) Homemade rock grinder based on a kitchen knife sharpener. 3) A standard binocular microscope + a homemade polarized unit
My updated methods are as follows; The plastic arbors as alternatives to metal arbors, which fix a diamond blade or a diamond plate on the motor rods, are made by a cheap 3D printer, Cleality Ender 3 Pro (250USD). Homemade polarized unit bodies (previously made of acrylic plates) for a standard microscope to use as a polarized microscope are similar. The bottom LED system for the USB microscope was also improved. The merit of such improvement using a 3D printer is that the 3D CAD data (.stl files) are freely distributable from our website. So, no other technical skills such as metalwork, which relies on special training and high-expensive tool, are needed, although some easy additional work is still necessary. For plastic printing, it is recommended to use filament like nylon or PET because they are strong under intense stress and/or water filling condition. However, we now use standard PLA filaments, cheap and widely used. There is no inconvenience on this use by this time.
One further trial is to use a kitchen knife sharpener as a rock-saw. We made a new arbor to hold a thin diamond blade on the knife sharpener's wet stone and try to use it as rock cutting instead of the bench-grinder-based tool. Because our previous developed rock-saw based on a bench-grinder has a fatal drawback of their structure; the water from the water tank is invaded to the inside through the motor rod and rusted the bearing; finally, the motor does not work. Our 3D printer also made this arbor used on the knife sharpener. Although the 3D CAD software (Autodesk Fusion 360) has the function of creating a screw trench coupled with the motor rod, the screw trench sometimes would not go well due to the thermal expansion. So, we need only some additional smooth tapping on this screw hole before use. In this new tool, the saw's clearance is not so broad, and the main motor of the knife sharpener has less torque and speed than a bench-grinder, so we can only cut a small tip by this saw. However, it is enough to make a small number of thin-sections, and this is suitable for geoscience club students to use in a classroom safely. The water-proof system works quite well. We can purchase the diamond blade (150mm diameter, 0.5mm thickness) from a Chinese net shop at around 4 USD, including the shipping cost!
Our making and observing methods are improving now based on our trial experience for a couple of years. The basic concept is to make it easier, use only cheap mass production tools, and avoid special skills and high-expensive tools. So the details of our plans are now available and updated on our website (http://www.yossi-okamoto.net/). The contents are written both in Japanese and English for school use in foreign countries. Our method was presented in the teacher share online meeting at KVIS-SIF2021 (Thailand), one of the best Thai science highschools I already taught as a visiting teacher.
The base tools are not changed 1) Homemade rock saw employing a bench-grinder, 2) Homemade rock grinder based on a kitchen knife sharpener. 3) A standard binocular microscope + a homemade polarized unit
My updated methods are as follows; The plastic arbors as alternatives to metal arbors, which fix a diamond blade or a diamond plate on the motor rods, are made by a cheap 3D printer, Cleality Ender 3 Pro (250USD). Homemade polarized unit bodies (previously made of acrylic plates) for a standard microscope to use as a polarized microscope are similar. The bottom LED system for the USB microscope was also improved. The merit of such improvement using a 3D printer is that the 3D CAD data (.stl files) are freely distributable from our website. So, no other technical skills such as metalwork, which relies on special training and high-expensive tool, are needed, although some easy additional work is still necessary. For plastic printing, it is recommended to use filament like nylon or PET because they are strong under intense stress and/or water filling condition. However, we now use standard PLA filaments, cheap and widely used. There is no inconvenience on this use by this time.
One further trial is to use a kitchen knife sharpener as a rock-saw. We made a new arbor to hold a thin diamond blade on the knife sharpener's wet stone and try to use it as rock cutting instead of the bench-grinder-based tool. Because our previous developed rock-saw based on a bench-grinder has a fatal drawback of their structure; the water from the water tank is invaded to the inside through the motor rod and rusted the bearing; finally, the motor does not work. Our 3D printer also made this arbor used on the knife sharpener. Although the 3D CAD software (Autodesk Fusion 360) has the function of creating a screw trench coupled with the motor rod, the screw trench sometimes would not go well due to the thermal expansion. So, we need only some additional smooth tapping on this screw hole before use. In this new tool, the saw's clearance is not so broad, and the main motor of the knife sharpener has less torque and speed than a bench-grinder, so we can only cut a small tip by this saw. However, it is enough to make a small number of thin-sections, and this is suitable for geoscience club students to use in a classroom safely. The water-proof system works quite well. We can purchase the diamond blade (150mm diameter, 0.5mm thickness) from a Chinese net shop at around 4 USD, including the shipping cost!
Our making and observing methods are improving now based on our trial experience for a couple of years. The basic concept is to make it easier, use only cheap mass production tools, and avoid special skills and high-expensive tools. So the details of our plans are now available and updated on our website (http://www.yossi-okamoto.net/). The contents are written both in Japanese and English for school use in foreign countries. Our method was presented in the teacher share online meeting at KVIS-SIF2021 (Thailand), one of the best Thai science highschools I already taught as a visiting teacher.