OpenFlexure Introduction
The OpenFlexure (rendering on the left from OpenFlexure website) is a fully open-source, inverted-geometry, low-drift mechanical microscope actuated by normal stepper motors controlled by a Raspberry Pi. It can use either the standard RasPi camera or lab-grade RMS threaded optical components. It's design is unique in that it uses printed "flexures," or flexible joints, in place of hardware, meaning that it has a healthy lifespan, low backlash, and simple assembly.
Here is an overview.
This project leapt out to me because it is inexpensive, relatively simply to begin, and practically infinitely extensible. After getting the machine working, I intend to develop my machine learning skills through automatic classification of soil microbes.
Electronics
I chose to order the parts for the simplest version of the microscope with thoughts of upgrading it later. We already had a Raspberry Pi, camera, and appropriate screen on-hand from other projects.
Printed Parts
The parts printed without trouble on the trust Ender 3 in Hatchbox black PLA. I attempted a print with PETG, hoping to keep the joints flexible, but experienced too much stringing for my taste.
Assembly Pt 1
The motors were installed without issue. In the picture, the z-axis motor is not installed because the hardware store only had two of the requisite three o-ring tensioners. The electronics presented my first hurdle: it simply doesn't work yet. The pi (not pictured) connects to the camera and I see an image, but the Arduino Nano does not seem to be getting power (power source not shown).
Assembly Pt 2
After updating the software, redoing my wiring, and figuring out a motor power supply, the microscope worked.
A more busy version of me would have left the project there and begun to work on software; however, I am stuck at home.
Assembly Pt 3
I printed cases for the raspberry pi and motor drivers (modified to fit my drivers and an Arduino nano) and integrated all the electronics. I also ditched the touchscreen in favor of an Ethernet-Ethernet connection of my desktop.
It turned out that, in our house full of electronic bits and bobs, we had no female-female jumper wires. The least enjoyable part of the build was converting 26 female-male wires into 13 female-female and 13 male-male. Even the wire harness soldering felt more creative.
Meteorite Thin Section
Cucumber Ovary
Cabbage Leaf
Onion Skin
Corn Stem
