Introduction: How to Restore, Improve, and Digitize an Old Microscope
Second Prize in the
Build My Lab Contest
This microscope was discarded because the lighting mechanism it came with had stopped working entirely. Changing the light bulb did not fix the problem, and because the whole electrical mechanism had been epoxied into a solid slab during the manufacturing process, it was impossible to see which individual component had gone bad. The rest of it, however, worked just fine. The optics were in good shape, all of the dimensional stages worked, just no light. Because the microscope was manufactured in the 80’s in West Germany, it was unlikely that finding a replacement to the whole lighting unit would be possible or cost effective. Not to mention that, when it had worked, it used a ton of power and expensive, extremely hot, bulbs that tended to burn out anytime the microscope was left on overnight. So I got rid of the whole lighting mechanism, which was archaic, inefficient, wired and heavy. I replaced it with a simple housing that allowed me to plug in an LED light and power it from a cheap 3.3V coin cell battery I had lying around.
With the lighting situation fixed, I turned to improving the current setup. The optics worked just fine, but I wanted to be able to take pictures of what I was seeing, and while I’m doing that, why not just turn it into a digital microscope and not even bother straining your eyes looking through the eyepiece. I had a high quality webcam lying around and liked that it has some of the best light-correction I have seen on a webcam. But as anyone who has ever tried to line up a camera with a lens before can tell you, even the slightest misalignment produces blurred, unusable pictures. So I designed and and printed an adapter to solve this issue.
Step 1: Items I Used
Ingredients of this project are:
-partially functioning microscope
-old coin cell battery holder from electric candle
-3.3 V coin cell battery
-3.3V White 5mm LED
-SPST Push-on Push-off button
-3D printed camera to eyepiece adapter
-Microsoft 1080p lifecam
-6 M3 15mm screws
-6 M3 washers
-6 small springs
Step 2: Removing the Offending Lighting Structures
Unfortunately I had already removed and thrown out the electrical components by the time I thought to take pictures of it. So there aren't any, but there wasn't a lot to look at anyway, because it was just a solid slab of black epoxy with a cord coming out of it and a couple wires going to the bulb housing (which I kept). There were just 3 screws holding in the slab. Once removed I simply unplugged the wires to the bulb housing.
Step 3: Finding a Light
Finding a light source was not hard... I reached all the way across my desk where I keep my LED's and grabbed a 3.3 V 5mm white LED from radio shack. I had scavenged a coin cell battery holder from an electric candle that had a small plug already incorporated into the circuit. This plug happened to fit the LED wires perfectly, holding it snugly, but not so tight that switching it out would be difficult. I simply aligned the plug to hold the LED where I wanted it and hot glued it in place.
I bent the LED leads at 90 degrees so that the LED would point directly up through towards the slide holder and into the objective. As you can see I left the rest of the housing intact as it contained a reflector behind the LED and would fit nicely into the light bulb spot without any other modifications.
Step 4: Installing an ON/OFF Button
This is fairly straightforward. I just used a SPST Push-on Push-off button from radioshack that happened to fit through the hole where the brightness adjustment knob had been before. Then connected the wires from my new light.
Step 5: 3D Printing Time!
You can, of course, make adapters that are not 3D printed and would serve the same purpose, but I happen to have a 3D printer, and like the ability to try multiple renditions of a piece before decided which one to use. Plus, once you have the piece drawn up and started the print, you can go do something else while it prints. Let the bot do all the work hard work. This was printed on a home brew MendelMax in PLA.
You can find the settings for slicing, the .stl and .skp files here.
Obviously the internal sizes of the adapter will depend on the microscope and camera you use, but hopefully the design is simple enough that if you cannot edit the .skp to meet your needs, than re-drawing it won't be too cumbersome. It only took me a few tries to come up with this one, and I was going for simplicity.
After it is printed out, just drop the M3 nuts into the nut-traps and thread the springs and washers. Then Screw! I made the internal portion that fits over the eye piece tapered so it would fit snugly on when pressed in. The design works well with this microscope because the eyepiece has a rubber coating on the outside which the adapter grips well.
Once I had the proper dimensions worked out for the adapter, and had assembled the spring-screws, it was time to connect camera to microscope. If you have ever tried to line up any sort of magnifying lens situation with a digital camera before, you can appreciate the frustration and difficulty of getting it EXACTLY lined up with the viewable picture coming through the eyepiece. But we now have six points of adjustment, so we can get it there and keep it there.
I started by placing the camera flat on the desk facing upward. Removing the eyepiece from the microscope means I will be able to center the viewable area before I do the initial tightening of the screws. Then just tighten them one by one until the fit is snug and the picture looks like the one in the picture where the "circle" of light is more or less centered and the edges of it are relatively crisp. If the edges are blurry then its not correctly aligned and won't be able to get the whole field of view in focus. Also, there is no way that I have found to get rid of the black edges around the circle. The viewable part of a microscope is round, and thus will always be round when you take a picture of it. It just looks funny because we are used to viewing things on a screen that is rectangular, but square optics are hard to make... If it bothers you, you can decrease the amount of space the black edges take up by using the digital zoom on the camera, or find a round screen.
Step 7: And Now We Have a Functioning Digital Microscope
No more straining my eyes peering through the eyepiece while I move the stages around to find my target. I can now comfortably use my computer screen to search for, and image whatever I am viewing.
Step 8: Fixing Light Artifact
There are still a few bits that need to be ironed out. The blue light on the top of the camera is throwing some artifact into my field of view. I used electrical tape to block the light that leaked to the inside of the camera body.
Step 9: Fruit Fly
Here are just some quick images of small things I had on hand. A fruit fly, of the Genus Drosophila, I believe. I don't have the entomological prowess to give you the Species name as well, perhaps Melanogaster, but I can't tell these apart from the other anyway...
With these larger samples on a light microscope like this, I have to light them from the top as well as the bottom. Also, the plane of focus on this microscope is narrow enough that you'll notice that these bugs are not entirely within focus; just "slices" of them can be in focus at any one time.
Step 10: Ant
I happened to find a tiny ant walking along my floor as I was looking for things to take pictures of... it was this ant's lucky day, now it is famous.
Step 11: Surprise... Maggots!
So I also wanted to see what my dreaded nemesis, the housefly, looked like up close. And since there happened to be a couple buzzing around, I took more than the usual amount of pleasure at swatting them with my electric fly-swatter-tennis-racket-wand-thingy. (If you don't have one, get one... you will spend WAY more time than you ever thought possible swatting flies).
However, the super-satisfying electric snap that kills the fly, did nothing, as I was soon to find out, to it's belly full of progeny who were ready and waiting to be deposited on a nice piece of poo somewhere.
When I positioned the fly on the microscope, I noticed that it had begun to move, but not in a way that the fly, as an organism, would normally move. Rather something was moving it from the inside. What ensued for the next few minutes was the microscopic equivalent of the Aliens movie. Around 20 brand new larvae emerged from the fly's dead body. It was amazing, it was grotesque, it was biology in action. Since the fly's body had ceased to function, the stress placed on the larvae inside caused them to force their way out of their mother into the surrounding environment in search of food and a nice place to grow before morphing into an obnoxious, winged annoyance. Unfortunately for them, when they made it out of mom, all they found was the glass of my microscope slide.
Step 12: Now for Some Cell Biology
Just to get a idea of what can be done with my new tool. Here are some shots of a specimen of my blood, at various dilutions, lighting conditions, and magnifications.
The 100X objective is technically an oil immersion objective, but lacking any immersion oil, I used water instead, which has a decent index of refraction, but just doesn't work as well as the oil. So the "1000X" label in the pictures is only ~1000X.
Step 13: Where to Take It From Here...
There is still a lot of potential in this project that I have not yet fully explored.
Some of these things are:
-Different colored lights or filters.
-UV light, assuming I have something labeled that will fluoresce when hit with UV.
-Software that will allow me to take full 1080p pictures and video. The stock software that microsoft ships with this camera will not support the full potential of the sensor (only 720p), but they also won't tell you what software does... much to my irritation.
-proper oil immersion
-of course, my slide preparations leave a lot to be desired, but a home lab with basically no reagents does not give me many options.
When I am able to make upgrades or get some particularly interesting images I will update this instructable. As always I welcome your comments and criticisms, as well as any corrections you might find. I entered this instructable in the "Build my Lab" contest. If you like what you see, please vote! Thanks for reading!
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