Build Your Own 3D Printed Open Source Motorized Microscope

I always enjoy a good 3D printed DIY project, whether it’s truly helpful or just for fun. These projects are even cooler when you add Legos into the mix, like Reddit user DIY_Maxwell did. He posted about his work using 3D printing, Arduino, Raspberry Pi, and Lego bricks to make an open source, motorized microscope. But, the microscope itself is not fully 3D printed – instead, the body was built with Lego bricks and some 3D printed components. What makes this project more awesome is the stop motion-style video he made showing the various parts of the project and how they all fit together to make a working microscope.

BUILD YOUR OWN MOTORIZED MICROSCOPE using 3D-printing, Lego bricks, Arduino and Raspberry Pi… all design files, source codes and detailed instructions are provided open-source. from r/3Dprinting

“I wanted to have a modular microscope, something I can easily modify for transmitted-light, reflected-light, cross-section, etc. My early prototypes did not have Legos, as I started making my own interlocking pieces, I realized that I was in fact printing lego-like designs, I thought buying legos would be less of an effort,” he wrote on Reddit when asked why he didn’t 3D print all the parts. “Then I found out about these “sliding” lego pieces, which are very precise for linear actuators. The other advantage is that, if I want to change the height of the camera let’s say, I simply add more bricks, it’s convenient.”

DIY_maxwell used FreeCAD to design the 3D printed microscope parts, which were fabricated on an Ender 3 system. All of the source codes and design files have been provided open source on GitHub, along with detailed step-by-step instructions on how to make your own.

Before you jump right in, do you know what exactly a motorized microscope does when compared to a regular microscope? DIY_maxwell explained that, at least for him, it needed to be able to tilt in order to take photos, from an angle, of “highly reflective surfaces (semiconductor chips),” and that it should quickly adjust the focus and magnification, and position of the sample.

“The microscope has a simple operation principle based on changing the magnification and the focus by adjusting the relative distances between a camera, a single objective lens and a sample. Briefly, two linear stages with stepper motors are used to adjust these distances for a continuous and wide magnification range,” the GitHub instructions state. “Four additional stepper motors tilt the camera module and change the X-Y position and rotation of the sample. A uniform light source illuminates the sample either from an angle (reflected light) or from the bottom of the sample (transmitted light).”

The main components of this modular, motorized microscope include a Raspberry Pi system, an 8 MegaPixel camera, six stepper motors, a keyboard or joystick for variable speed control, uniform illumination, and obviously plenty of Lego bricks. Depending on the specific features and electronics vendors used, the whole thing costs between $200-$400, and once you have all the parts in front of you, should only take a couple of hours to assemble.

The main body was built with individually-purchased Lego bricks, and DIY_maxwell designed custom actuators and 3D printed them, rather than using available motors and gears from LEGO Technic.

“This approach not only lowered the cost of the microscope but also gave me some flexibility in the design and implementation of precise linear and rotary actuators. In principle, the whole structure could be 3D-printed without using any LEGO parts but that would be less modular and more time consuming,” he writes in GitHub.

In addition, 3D printing offers you the flexibility of quickly changing the design for maximum optimization if and when it’s needed.

“If the parts do not match well, some minor modification in the original design file (e.g. enlarging the holes matching to LEGO studs) or polishing/drilling may be required,” he explained.

The contents of the motorized microscope are as follows:

  • Linear Actuators
  • Camera Module
  • Rotary Stage
  • Illumination
  • Tilt Mechanism
  • Electronics
  • Final Assembly
  • Software

You can find detailed instructions, images, slicer settings, tips, and more on GitHub, and a longer version of the assembly video can be viewed here.

Several other Reddit users who routinely use microscopes related how impressed they were about the project; a geologist mentioned that “starting price can be anywhere between $500 to $1000 for something with that kind of quality” when DIY_maxwell said that his microscope could “easily resolve 10um features.” A pathologist expressed excitement about “a modular system to motorize common non motorized microscopes (Leica, Olympus, etc.).” While the compliment was appreciated by the maker, it was noted that “this microscope is not meant to replace a lab microscope used for medical assessment. No dark-field, no fluorescence, no aperture control, it suffers from chromatic aberration and other optical effects at high magnification, etc.”

“I hope this prototype persuades other DIY-enthusiasts to develop new designs of microscopes.”

If you’re interested in using 3D printing to make your own microscope, you can check out all of the relevant information on GitHub to build this one, or check out the OpenFlexture Microscope project on Wikifactory. This was created as “part of the Waterscope initiative, which by allowing for fast and affordable on-site bacterial testing of the water quality in developing regions of the world, is helping to cope with the diseases caused by bad quality water drinking.”

OpenFlexure Microscope

The OpenFlexure can be built in the classroom and used as an education tool for both students and teachers. Because the 3D printed microscope stage uses plastic flexures, the motion is free from friction and vibration, and the four-bar linkages in the stage can be 3D printed in a single job with no support material.

You can find other open source 3D printable microscopes on Thingiverse as well; happy making!

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The post Build Your Own 3D Printed Open Source Motorized Microscope appeared first on 3DPrint.com | The Voice of 3D Printing / Additive Manufacturing.

Michigan Tech’s Joshua Pearce launches free open-source 3D printing course

One of the most popular open-source 3D printing courses, taught by Dr. Joshua Pearce at the Michigan Technological University is now available online for free. Dr. Pearce, an open-source champion and professor of Materials Science & Engineering and the Electrical & Computer Engineering at Michigan Tech is the author of Open-Source Lab: How to Build […]

Desktop 3D Printing and Functional Replacement Parts

3D printing is seeing increasing use in the manufacture of components for bikes, and sometimes even the bikes themselves. Bikes with 3D printed parts don’t just look cool, either – they perform just as well as, and sometimes even better than, regular bikes.

Open source advocate and 3D printing educator at Michigan Tech Dr. Joshua Pearce recently published an Ultimaker blog post about how to use your desktop 3D printer to create functional, inexpensive replacement parts for complex machines that require mechanical integrity – like bicycles.

Dr. Pearce’s team partnered up with the research group of John Gershenson. Dr. Pearce, Gershenson, Nagendra Tanikella, and Ben Savonen completed a study on the use of open source 3D printers for making components for the popular Black Mamba bicycle.

Dr. Pearce wrote, “Specifically, we chose to start tests with pedals that fail often and have clear standards namely the CEN (European Committee for Standardization) standards for racing bicycles for 1) static strength, 2) impact, and 3) dynamic durability.”

First, the teams used parametric open source FreeCAD to design a custom CAD model of a replacement pedal; the model and STL files are available for download from Youmagine. The pedal was made using the most common 3D printing material – biodegradable, inexpensive PLA.

Static strength test

The pedal was first subjected to a 1,500 N vertical downward force under the CEN static strength test, which found no fractures. Then, the pedal was tested to a 3,000 N compression load applied pedal uniformly – this is actually twice the required amount, which meant that the pedal well exceeded the standard, and, as Dr. Pearce put it, was able to “clear the first hurdle!”

A mass of 15 kg was dropped onto the pedal from 400 mm up, 60 mm from the mounting face, for the CEN bicycle pedal impact resistance test. While the test resulted in a minor dent, there weren’t any fractures – another test passed.

In order to simulate a real-world bicycle, with a person on the pedals, the CEN developed its dynamic durability test for bike pedals. For this test, the research groups had to spin the spindle at 100 rev/min for 100,000 revolutions; at the same time, the pedal also had a mass of 65 kg suspended only by a string. Just like with the static strength test, the pedal’s dynamic durability was designed to exceed the CEN standard under normal conditions.

Impact resistance

Rather than using a rig, the team attached the 3D printed pedal to a bicycle for direct testing, and went 200,000 revolutions with a person’s 75 kg weight being carried solely by the pedals. Again, this was twice the CEN standard, and passed again – I’m sensing a theme here.

Dr. Pearce wrote, “Our humble 3D printed pedal is now good enough for European [racing] bikes…but wait it is actually better!”

The 3D printed pedals are nearly a third of the moss of the Black Mamba stock pedals, which is performance-enhancing as well as cost-effective…if raw PLA pellets or recycled materials, like ABS, nylon, or PET, are used, that is.

Dr. Pearce also provided some easy, DIY guidelines to achieve lab-worthy results for the 3D printed pedals, so you won’t have to redo any bike part experiments.

First, look into expertise already available through a study that researched the parts you were interested in, such as this one regarding the viability of distributed manufacturing of 3D printed PLA bike pedals. Then, determine the material’s mechanical requirements – check out this study for a handy open access list of most of the commonly available tensile strengths of the more common 3D printing materials.

Sub-optimal layers

Print the component in the right material, and with required infills, to achieve your application’s desired mechanical properties. Then, make sure to check out the print’s exterior for any sub-optimal layers from under-extrusion – if the part is under-extruded, fix your 3D printer and try it again.

Finally, weigh the part to make sure there isn’t any under-extrusion inside that you’re not able to see; Dr. Pearce explained that a digital food scale has “acceptable precision and accuracy” for most prints done on extrusion-based 3D printers.

“This mass is compared to the theoretical value using the densities from this table for the material and the volume of the object,” Dr. Pearce said.

The previously mentioned study with the list of tensile strengths was able to find a linear relationship between a 3D printed part’s ideal mass and the maximum stress able to be undertaken by samples. You can just check the study to see how far off from the ideal your part is, and then determine if it needs to be reprinted before figuring out the high probability of your needed properties.

According to mechanical studies completed on many extrusion 3D printers, open source machines produce stronger prints than proprietary systems, mostly thanks to the setting limitations of the latter.

“But be aware that there is a range and the properties of your parts will depend a lot on your machine and the settings you use,” Dr. Pearce warns. “In general printing at the high end of the extruder temperature range for your material will result in a higher strength.”

Just use that weighing technique, and compare your part’s mass to the ideal, to find out where it will most likely lie on the strength range.

You can read Dr. Pearce’s full rundown at Ultimaker.

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