Homemade microscope for repair and soldering. DIY microscope - step-by-step instructions on how to make a homemade soldering device
A microscope for soldering is a device that allows many people to carry out precise work on electronic cards, microcircuits and much more. When you are engaged in repairs and restoration of all kinds of electronic devices, you are periodically faced with the need to work with small parts.
Thus, a USB microscope designed for, as well as other small parts, would be an excellent assistant. The modern variety of devices allows a person to choose an excellent microscope specifically for their needs.
Application area:
- Precision work;
- Inspection of surfaces, as well as quality control;
- Soldering and installation of electronic boards.
A USB microscope, designed for soldering small parts and microcircuits, is used in most cases to detect microcracks in motherboards. The mechanisms of most modern USB microscopes are equipped with manual focusing, continuously variable magnification, illumination and other useful functions. The USB cable, through which information is transferred to a personal computer, also greatly simplifies the work, as well as the fact that it is equipped with backlighting.
Using special software with a scale, the USB microscope can also be used to measure angles, distances, areas and radii of magnified objects down to the micrometer.
It is worth paying attention to the fact that most modern microscopes are equipped with illumination, the ability to transfer data to a computer, as well as many other useful features for soldering. They also have the ability to work as a webcam.
With the help of this device, it is quite possible to take digital photographs of microcircuits, subsequently enlarge them, shoot videos and transfer all useful information to a computer for subsequent study of all the details of the work.
Technical data
A modern microscope is the latest device, equipped with illumination for soldering microcircuits and other small parts. In this regard, you need to know the technical data of the useful device.
Technical data:
- Camera: 2.0 MPixel (most microscopes are equipped with such a camera);
- Magnification: 20-200x;
- CMOS image sensor;
- Manual focusing within 10-500 millimeters;
- Photo format: BMP or JPEG;
- Video format: AVI with the possibility of 30 frames/second;
- Lighting: in most cases there are 8 LEDs with the ability to adjust brightness (using the backlight makes work much easier);
- Photo/video resolution: 2560×2048 (5M), 2000×1600, 1600×1280 (2M), 1280×1024, 1024×960, 1024×768, 800×600, 640×480, 352×288, 320×2 40 , 160×120;
- The power source allows you to use the USB port of a laptop computer, without the need for an additional battery;
- System requirements are mostly similar: Windows® in 2000 / XP/Windows Vista -/Windows 7.
What is included?
A modern soldering device includes the following components:
- Microscope;
- USB cable;
- Tripod;
- Guide to using the IC soldering tool;
- Software with all necessary drivers;
Features of the microscope
It is worth noting that today solders are not too eager to purchase these devices for soldering, believing that the usual magnifying glass, worn on the head, is much more convenient and simpler. Of course, a magnifying glass is much simpler, but in all other respects a magnifying glass is inferior to a microscope (it is not equipped with illumination or communication with a computer).
Like any modern device designed to make work simpler and less labor-intensive, a microscope has a number of significant advantages over such a device as a magnifying glass, thanks to which the shareholder can forget about how he previously used a magnifying glass attached to his head for these purposes.
Microscope Features:
- Compactness;
- Portability;
- Light weight;
- Adjustable zoom (magnification) of the lens;
- Possibility of illumination of the part being repaired;
- High sharpness;
- Equipped with high-quality lighting;
- Ease of replacing any elements of the device;
- Additional accessories for the safety of the device during transportation;
- Ease of use;
- Ability to work with photographs and videos.
DIY microscope
If you are tired of having a magnifying glass on your head, it will be interesting to know that you can make a homemade microscope for high-quality soldering. However, this will require a little skill and a minimum of old equipment. Of course, to make a microscope with your own hands you will need a children's equivalent - a toy microscope. You can use an old children's device, such as the Naturalist. In addition, you will have to use a webcam, which you are unlikely to use anymore.
Let's say right away that if you are not sure that you will finish the job, and a magnifying glass is a more familiar device for you, it is better not to start, because otherwise you risk wasting time, as well as using up materials that may still be useful. In this case, it will be better to purchase a new device for soldering microcircuits. But for those who are confident, the procedure is presented below.
Procedure:
- First, we will prepare materials for work, organize a workplace;
- After that, take the webcam, and then screw it into the eyepiece. You can use plastic glue to secure the camera;
- Next, we use a transistor in SOT-23 (actual size 3x3 millimeters) or a resistor 1206, the length of which is 3x2.6 millimeters;
- If desired, the microscope can be equipped with illumination.
With little effort and time, you can use a DIY USB microscope without straining your eyesight, and you won’t need a magnifying glass. Thus, a microscope successfully replaces a magnifying glass.
When buying any product from Chinese sellers, you need to be very careful, since often, I would even say regularly, in order to promote their products, sellers indicate deliberately inflated characteristics in the descriptions of their products. In fact, you have to rummage through mountains of advertising garbage to find an adequate description and buy a quality product. But sometimes, not often, the opposite situation happens. When the presented description of the product is not complete and in fact such a description hides the unique advantages of the product. This material will reveal one of these hidden gems.
The topic of the “correct” microscope for soldering is not new. Many have already tried to find a solution to this problem. The problem exists because modern electronics use increasingly smaller parts and increasingly dense installations. The details become so small that they are difficult to even see with the naked eye. And it is almost impossible to work with such components without auxiliary optical devices.
There are actually several approaches to solving this problem on the market:
- this is the use of magnifiers, both stationary and worn in the form of glasses
- this is the use of optical microscopes, conventional and stereo
- and the most fashionable solution is the use of digital microscopes.
- A regular magnifying glass either has insufficient magnification or must be placed very close to the object.
- Optical microscopes are not cheap and have very limited working space
- Any optical device, magnifying glass or optical microscope, creates serious strain on the eyes. The use of magnifying glasses is especially harmful to the eyes.
- Cheap digital microscopes, as I call them “microscopes on a stem,” transmit images with a long delay and have too short a working distance to the object, which makes them very inconvenient to use.
- Expensive digital microscopes have a high price, realistically $150-$250 for a complete set. However, they do not provide high magnification, do not allow working at an angle, take up too much space on the table, the large lens and camera obscure the view and interfere with work if the lens is lowered low.
We will talk about a relatively new line of USB microscopes. This microscope was developed by the company and has a price of about $50. Later, a number of identical clones appeared, which do not differ from the original in terms of performance characteristics, appearance, or configuration, but have a price of about $35. Both of these microscopes have already been reviewed. Therefore, I see no point in repeating what has already been said in previous reviews. I recommend viewing them, since further we will talk about questions, as if in continuation of these reviews.
I bought myself a clone, because if there is no difference, why pay more. But I’m practically sure that everything said below will be true for the original from Andonstar. The purpose of this review will be to measure the actual characteristics of a microscope, and will also show how to properly use a microscope so that these characteristics can be used in practice.
Tripod
The theater starts with a hanger, and the USB microscope starts with a tripod. A tripod for a microscope is an extremely important thing. Because when working at high magnifications, the positioning accuracy of the microscope should be at the level of tenths or even hundredths of a millimeter. Therefore, it is extremely important that the tripod allows you to choose an arbitrary height and position of the microscope, and also allows you to correctly make micro-corrections of the position.There is no point in discussing a microscope stand on a leg. This is not a tripod. It is extremely difficult to use at high magnifications. 
In a monitored microscope the situation is much better than in microscopes on a stem. But still, it must be admitted that this tripod only partially solved the problem. Vertical positioning works very accurately, like other adjustments, but the problem is with horizontal play. Initially, this tripod was designed so that it always has horizontal play. But I didn’t expect it to be so big. Simply put, the microscope actually dangles in a horizontal plane. My bump is about 7mm. It is clear that working with such a backlash is almost impossible. Because with any attempt to change the height or focus settings, the picture goes far beyond the frame.
Judging by the design of the tripod, it is theoretically impossible to completely eliminate the backlash. But, nevertheless, a quite convenient solution was found, which almost completely neutralizes the backlash, even at the highest magnification. To do this, just secure the elastic band. Photos explain everything better than words. The main thing is to choose the right tension force for the elastic band. It is also important not to put the elastic band too tight.
Tripod photo
Example of backlash, shift to the right 
Example of backlash, shift to the left 
Solution 
Disassembled tripod, in extended position. The axle is extended and has some play. 
View from below. In the distance you can see a pin moving along a groove. Due to the fact that this pin is slightly narrower than the groove, play occurs. 
Bottom view, the axle is retracted as much as possible. Pin close up 
Groove close up 
Maximum microscope magnification
This is the main question for microscope sellers and owners, to which no one knows the exact answer. The whole difficulty lies in what and how to measure. More precisely, the problem is not that there is no standard method for determining the maximum magnification of a microscope. Each seller for a microscope on a stem sets, depending on the level of arrogance, the maximum magnification number they like. Nowadays you can find the same microscope model, like the one in the picture above, indicating the maximum magnification x200, x500, x800, x1000 and even x1600. Although, in reality, few people manage to see more than x200.Since there is no standard method, measurements of the maximum magnification will be carried out using common sense.
To determine the magnification of a microscope, you need to determine the size of the visible area in the microscope and the size of the visible part of the image on the computer screen. If we choose a 10-inch netbook display and a 60-inch TV screen as a basis, then formally the same image on the TV screen will have a magnification of 6 times greater. But it is clear that few people use a 60-inch TV as their main monitor. I think it would be correct to take a 27-inch monitor screen with FullHD resolution as the basis for the calculation. For such a monitor, we can consider the width of the visible part of the display to be 60cm.
This is a shot of a metal ruler at maximum magnification. The photo was taken with a real resolution of 1600x1200. 
This image highlights the fragment shown in the previous image. 
According to the data from the image, the width of the selected part of the image is 1.23mm. This means that these images on a 60cm wide monitor screen will be shown with a magnification of x487.5 times. Taking into account that the width of the monitor may be slightly wider, we can safely admit that the maximum magnification x500 indicated in the microscope description is true.
At the same time, if we take the huge fleet of microscopes on a stem as a basis, most of them have a 640x480 matrix, and high resolutions are achieved through interpolation. But in order to correctly compare the resolutions of microscopes, in theory you need to make a comparison with the same image resolution. That is, to turn the top image into a maximum resolution image suitable for comparison, you need to select a fragment measuring 640x480 from the upper left corner of the image, and cut off the rest. 
For such a picture, the resolution of this microscope will be equal to x1219.5. It’s strange that the Chinese didn’t think of comparing the resolution of microscopes at a fixed frame size.
These are not inflated numbers, the software for displaying the image can do such magnification on the fly, so the microscope can actually work and produce an image resolution greater than x1200 times. In fact, this is a digital zoom, only in our case it is implemented not by the hardware of the microscope, as is done in sophisticated digital microscopes, but at the software level in the viewer program.
Therefore, if you indicate the maximum resolution of the microscope, then you must indicate for what frame resolution this magnification was calculated.
Distance from microscope lens to object
The distance from the microscope lens to the observed object is critically important in the case of soldering and other work. It is important that the microscope is located at a sufficient distance from the object of observation so as not to obscure the view or interfere with work. A series of measurements were made, at what magnification, what distance should be to the microscope.
For soldering, in my opinion, the optimal frame width is around 20mm-40mm. With such a working field, the distance from the microscope is approximately 40mm-70mm. At this distance, the microscope does not interfere with your work at all. In addition, for soldering, I prefer to point the microscope not strictly vertically, but at an angle of 30 degrees from the normal, which seems to me more convenient than a purely vertical installation of the camera.
If we compare with professional solutions, the price is around $200, something like or or a complete set as in the picture: 
Such a microscope provides a magnification of x50 for a resolution of 1920x1080 at a distance of about 20cm from the object. Of the minuses: the maximum magnification is not that high, only about x175, and it requires an almost close zoom. But it’s one thing when you tightly place a thin tube with a diameter of 1 cm, and another thing when you have to move this entire mighty combine. I believe that the acquisition of such a colossus is not justified.
Picture lag
The biggest problem with USB microscopes is image lag. If you move an object into the field of view of the microscope camera, the image on the monitor screen will not be updated immediately. All microscopes on a stem usually have two main operating modes available: 640x480 at 30 fps, and 1600x1200 at 5 fps. Working with a picture at 5 fps is torture. Or you need to get used to it when after each movement you need to stop and pause.This microscope has no problems with lag. Everything is updated quickly, and is not at all annoying when working. What was noticed by the authors of previous reviews. But sensations are one thing, but I want exact numbers, which will be given later.
The video stream can be transmitted either in yuyv422 format or in mjpeg format. It is extremely important to use only the mjpeg video stream format to view the video stream. The frame refresh rate for high resolutions for mjpeg is significantly higher than for the yuyv422 format. And compiled for the main modes:
- 640x480 at 30 fps
- 800x600 at 20 fps
- 1280x960 at 17 fps
- 1600x1200 at 17 fps.
By the way, to understand how cool everything works in mjpeg mode, it’s very informative to try using the yuyv422 mode. To understand what microscopes on a stem see and can do.
In addition, this microscope has one hidden advantage. If the video stream format is selected as mjpeg, then in the case when you need to capture video, you can not recode the captured video using the processor, but send it as is, directly from the microscope to a video file. This mode of operation has a number of advantages. In this mode, the CPU is unloaded from work. This means that it not only heats up less and consumes less energy. This means that even on the weakest processors you can successfully capture video at maximum resolution without frame drops.
Unfortunately, only a small number of programs can work with video in this way. I know of only three such programs: AMCap, FFmpeg and VirtualDub.
To select this mode in AMCap, you need to specify the type of video stream from the microscope camera as mjpeg, and the encoding format when recording video as “No encoding”.
For FFmpeg you just need to add the command line option -vcodec copy.
Capture video and record to a file without recoding the video stream:
ffmpeg -s 1600x1200 -rtbufsize 100MB -f dshow -vcodec mjpeg -i video="USB Camera" -vcodec copy -y output.mp4
Watch video:
ffmpeg -video_size 1600x1200 -framerate 30 -rtbufsize 100MB -f dshow -i video="USB Camera" -pix_fmt yuv420p -f sdl "Microscope Video"
View video with scaling to the selected resolution. You can substitute any other resolution instead of 640x480:
ffmpeg -video_size 1600x1200 -framerate 30 -rtbufsize 100MB -f dshow -i video="USB Camera" -pix_fmt yuv420p -vf scale=640:480 -f sdl "Microscope Video"
View video with scaling, but at the same time the resolution will be scaled on the X axis to 1280 resolution, and on the Y axis the resolution will be selected automatically:
ffmpeg -video_size 1600x1200 -framerate 30 -rtbufsize 100MB -f dshow -i video="USB Camera" -pix_fmt yuv420p -vf scale=1280:ow/a -f sdl "Microscope Video"
Viewing video with scaling, but at the same time the resolution will be scaled along the Y axis to 1060 resolution and on the X axis the resolution will be selected automatically:
ffmpeg -video_size 1600x1200 -framerate 30 -rtbufsize 100MB -f dshow -i video="USB Camera" -pix_fmt yuv420p -vf scale=oh*a:1060 -f sdl "Microscope Video"
Viewing video with 640x480 scaling and simultaneous recording of video to a video file without recoding the video stream:
ffmpeg -s 1600x1200 -rtbufsize 100MB -f dshow -vcodec mjpeg -i video="USB Camera" -vcodec copy output.mp4 -pix_fmt yuv420p -vf scale=640:480 -f sdl "SDL output"
Parsing a video file containing an mjpeg video stream without recoding and loss of quality into separate jpeg files:
ffmpeg -i mjpeg-movie.avi -c:v copy -bsf:v mjpeg2jpeg frame-%04%d.jpg
There is no need to make any special settings in VirtualDub.
Video Lag Measurement
Measuring video lag is easy. To do this, you need to place your smartphone next to the computer monitor on which the video from the microscope is broadcast, so that the smartphone screen is filmed by the microscope. You need to launch the stopwatch application on your smartphone. Next, you need to take another device: a video camera, another smartphone, a camera, or any other device that can record video. Point it so that the screen of the smartphone with the stopwatch numbers appears in the frame, as well as the picture transmitted from the microscope to the monitor, which also shows the stopwatch numbers from the smartphone. Next, we start recording video. And after finishing, we compare the time indicators on the monitor screen and on the smartphone screen. The delay between the appearance of the reading on the computer monitor is that very malicious video delay, which greatly interferes with your work.The experiment was carried out three times, each time using different video capture programs. Capture was carried out only in 1600x1200 mode with video scaling to fit the screen size so that the video was as large as possible, but without distorting the proportions.
First test
AMCap is used as the capture program.
The delays were:
0.17 0.20 0.11 0.23 0.13 0.21 0.16 0.20 0.19 0.22 0.17 0.25 0.29 0.20 0.15 Average delay: 0.192 sec
Second test
FFmpeg is used as the capture program.
The delays were:
0.13 0.16 0.24 0.15 0.23 0.14 0.14 0.18 0.13 0.17 0.25 0.16 Average delay: 0.173 sec
Third test
VirtualDub is used as the capture program.
The delays were:
0.19 0.14 0.18 0.13 0.17 0.25 0.20 0.15 0.18 0.18 0.17 0.25 0.16 0.23 Average delay: 0.184 sec
These measurements confirmed the very high quality of the camera’s hardware video encoding. When transmitting video in digital format, a delay of one frame for encoding it, and another frame for decoding it is inevitable. At a frame rate of 17 frames, a delay of 2 frames will be equal to 2/17 = 0.1176 sec. Plus, you need to take into account that the frame rate of the monitor, which is updated once every 60 seconds, also contributes to the delay. We get 2/17+1/60 = 0.1343 sec. It can be seen that this delay is in exact agreement with the measured data, which indicates the reliability of the measurements.
FFmpeg won in this test, although the gap from AMCap is not large. But a big advantage of AMCap is that AMCap has a button for capturing individual screenshots. By the way, in this microscope it is done correctly, intelligently, unlike microscopes on a stem. In them, the button is located directly on the microscope. It is impossible to press the button without shaking the microscope. And in this microscope, the button is located on the cable, which allows you to capture individual frames quickly and efficiently.
Bottom line
Today, this is the best microscope for relatively little money, which is suitable not only for examining small objects, but also for small work, such as soldering, jewelry work, mechanical work (cutting a track on a circuit board under such a microscope is a pleasure).In terms of its consumer qualities, this microscope really competes with even much more expensive microscopes based on industrial cameras with large lenses.
A microscope is needed not only for studying the surrounding world and objects, although this is so interesting! Sometimes this is just a necessary thing that will make it easier to repair equipment, help make neat solders, and avoid mistakes in fastening miniature parts and their exact location. But it is not necessary to purchase an expensive unit. There are great alternatives. What can you make a microscope from at home?
Microscope from a camera
One of the simplest and most affordable ways, but with everything you need. You will need a camera with a 400 mm, 17 mm lens. There is no need to disassemble or remove anything, the camera will remain working.
We make a microscope from a camera with our own hands:
- We connect a 400 mm and a 17 mm lens.
- We bring a flashlight to the lens and turn it on.
- We apply a drug, substance or other micro-subject of study to the glass.
We focus and photograph the object under study in an enlarged state. The photo from such a homemade microscope turns out to be quite clear; the device can enlarge hair or fur, or onion scales. More suitable for entertainment.
Microscope from a mobile phone
The second simplified method for making an alternative microscope. You need any phone with a camera, preferably one without auto focus. Additionally, you will need a lens from a small laser pointer. It is usually small, rarely exceeding 6 mm. It is important not to scratch.
We fix the removed lens on the camera eye with the convex side outward. We press it with tweezers, straighten it, you can make a frame around the edges from a piece of foil. It will hold a small piece of glass. We point the camera with the lens at the object and look at the phone screen. You can simply observe or take an electronic photograph.
If you don’t currently have a laser pointer at hand, you can use the same method to use a sight from a children’s toy with a laser beam; you just need the glass itself.
Microscope from a webcam
Detailed instructions for making a USB microscope from a webcam. You can use the simplest and oldest model, but this will affect the image quality.
Additionally, you need optics from a sight from a children's weapon or other similar toy, a tube for the sleeve and other small items at hand. For backlighting, LEDs taken from the old laptop matrix will be used.
Making a microscope from a webcam with your own hands:
- Preparation. We disassemble the camera, leaving the pixel matrix. We remove the optics. Instead, we fix a bronze bushing in this place. It should match the size of the new optics; it can be turned from a tube on a lathe.
- The new optics from the sight must be secured in the manufactured sleeve. To do this, we drill two holes approximately 1.5 mm each and immediately make threads on them.
- We stick in the bolts, which should follow the threads and match in size. Thanks to screwing, you can adjust the focus distance. For convenience, you can put beads or balls on the bolts.
- Backlight. We use fiberglass. It's better to take double-sided. We make a ring of the appropriate size.
- For LEDs and resistors you need to cut small tracks. We solder it.
- We install the backlight. To fix it, you need a threaded nut, the size is equal to the inside of the manufactured ring. Solder.
- We provide food. To do this, from the wire that will connect the former camera and the computer, we bring out two wires +5V and -5V. After which the optical part can be considered ready.
You can do it in a simpler way and make a stand-alone light from a gas lighter with a flashlight. But when it all works from different sources, the result is a cluttered design.
To improve your home microscope, you can build a moving mechanism. An old floppy drive will work just fine for this. This is a once used device for floppy disks. You need to disassemble it, remove the device that moved the read head.
If desired, we make a special work table from plastic, plexiglass or other available material. A tripod with a mount will be useful, which will facilitate the use of a homemade device. Here you can turn on your imagination.
There are also other instructions and diagrams on how to make a microscope. But most often the above methods are used. They may vary only slightly depending on the presence or absence of key parts. But, the need for invention is cunning, you can always come up with something of your own and show off your originality.
DIY microscope photo
The high level of miniaturization of electronics has led to the need to use special magnifying tools and devices used when working with very small elements.
These include such a common product as a USB microscope for soldering electronic parts and a number of other similar devices.
Some experts believe that a USB device is optimal for making a household microscope with your own hands, with the help of which it is possible to provide the required focal length.
However, to implement this project, it will be necessary to carry out certain preparatory work, which will greatly simplify the assembly of the device.
As the basis for a homemade microscope for soldering miniature parts and microcircuits, you can take the most primitive and cheapest network camera like “A4Tech”, the only requirement for which is that it has a working pixel matrix.
If you want to obtain high image quality, it is recommended to use higher quality products.
In order to assemble a microscope from a webcam for soldering small electronic products, you should also worry about purchasing a number of other elements that ensure the required efficiency of working with the device.
This primarily concerns the illumination elements of the field of view, as well as a number of other components taken from old disassembled mechanisms.
A homemade microscope is assembled based on a pixel matrix that is part of the optics of an old USB camera. Instead of the built-in holder, you should use a bronze bushing turned on a lathe, adjusted to the dimensions of the third-party optics used.
The corresponding part from any toy sight can be used as a new optical element of the microscope for soldering.
To get a good overview of the desoldering area and soldering parts, you will need a set of lighting elements, which can be used as used LEDs. It is most convenient to remove them from any unnecessary LED backlight strip (from the remains of a broken matrix of an old laptop, for example).
Finalization of details
An electron microscope can begin to be assembled only after thoroughly checking and finalizing all previously selected parts. The following important points should be taken into account:
- to mount the optics in the base of the bronze bushing, you need to drill two holes with a diameter of approximately 1.5 millimeters, and then cut a thread into them for an M2 screw;
- then bolts corresponding to the installation diameter are screwed into the finished holes, after which small beads are glued to their ends (with their help it will be much easier to control the position of the optical lens of the microscope);
- then you will need to organize illumination of the soldering field of view, for which you will need previously prepared LEDs from the old matrix.
Adjusting the position of the lens will allow you to arbitrarily change (decrease or increase) the focal length of the system when working with a microscope, improving soldering conditions.
To power the lighting system, two wires are provided from the USB cable that connects the webcam to the computer. One is red, going to the “+5 Volt” terminal, and the other is black (it is connected to the “-5 Volt” terminal).
Before assembling the microscope for soldering, you will need to make a base of a suitable size. It is useful for wiring LEDs. For this, a piece of foil fiberglass, cut in the shape of a ring with pads for soldering LEDs, is suitable.
Assembling the device
Quenching resistors with a nominal value of about 150 Ohms are placed in the breaks in the switching circuits of each of the lighting diodes.
To connect the supply wire, a mating part made in the form of a mini-connector is mounted on the ring.
The function of a moving mechanism that allows you to adjust the sharpness of the image can be performed by an old and unnecessary floppy disk reader.
You should take one shaft from the motor in the drive and then reinstall it on the moving part.
To make it more convenient to rotate such a shaft, a wheel from an old “mouse” is put on its end, located closer to the inside of the engine.
After the final assembly of the structure, a mechanism should be obtained that ensures the required smoothness and accuracy of movement of the optical part of the microscope. Its full stroke is approximately 17 millimeters, which is quite enough to sharpen the system under various soldering conditions.
At the next stage of assembling the microscope, a base (worktable) of suitable dimensions is cut out of plastic or wood, on which a metal rod selected in length and diameter is mounted. And only after that the bracket with the previously assembled optical mechanism is fixed on the stand.
Alternative
If you don’t want to bother with assembling a microscope with your own hands, then you can buy a completely ready-made soldering device.
Pay attention to the distance between the lens and the stage. Optimally, it should be almost 2 cm, and a tripod with a reliable holder will help you change this distance. Zooming lenses may be required to inspect the entire board.
Advanced models of microscopes for soldering are equipped with an interface, which significantly relieves eye strain. Thanks to a digital camera, the microscope can be connected to a computer, record a picture of the microcircuit before and after soldering, and study defects in detail.
An alternative to a digital microscope is also special glasses or a magnifying glass, although a magnifying glass is not very convenient to work with.
For soldering and repairing circuits, you can use conventional optical microscopes or stereos. But such devices are quite expensive and do not always provide the desired viewing angle. In any case, digital microscopes will become more common and their prices will drop over time.
Due to the crazy pace of development of radio engineering and electronics towards miniaturization, more and more often when repairing equipment we have to deal with SMD radio components, which, without magnification, are sometimes impossible to even see, not to mention careful installation and disassembly.
So, life forced me to search on the Internet for a device, such as a microscope, that I could make myself. The choice fell on USB microscopes, of which there are a lot of homemade products, but all of them cannot be used for soldering, because... have a very short focal length.
I decided to experiment with optics and make a USB microscope that would suit my requirements.
Here is his photo:
The design turned out to be quite complex, so it makes no sense to describe each manufacturing step in detail, because this will make the article very cluttered. I will describe the main components and their step-by-step production.
So, “without letting our thoughts run wild,” let’s begin:
1. I took the cheapest A4Tech webcam, to be honest, they just gave it to me because of the crappy image quality, which I didn’t really care about, as long as it was working. Of course, if I had taken a higher quality and, naturally, expensive webcam, the microscope would have turned out with better image quality, but I, like Samodelkin, act by the rule - “In the absence of a maid, they “love” the janitor,” and besides However, I was satisfied with the image quality of my USB microscope for soldering.
I took the new optics from some children's optical sight.
To mount the optics in the bronze bushing, I drilled two ø 1.5 mm holes in it (the bushing) and cut an M2 thread.
I screwed M2 bolts into the resulting threaded holes, onto the ends of which I glued beads for ease of unscrewing and tightening in order to change the position of the optics relative to the pixel matrix in order to increase or decrease the focal length of my USB microscope.
Next, I thought about the lighting.
Of course, it was possible to make an LED backlight, for example, from a gas lighter with a flashlight, which costs a penny, or from something else with an autonomous power supply, but I decided not to clutter the design and use the power of the webcam, which is supplied via a USB cable from the computer .
To power the future backlight, from the USB cable that connects the webcam to the computer, I brought out two wires with a mini connector (male) - “+5v, from the red wire of the USB cable” and “-5v, from the black wire.”
To minimize the backlight design, I decided to use LEDs, which I removed from an LED backlight strip from a broken laptop matrix; fortunately, such a strip had been in my stash for a long time.
Using scissors, a suitable drill and a file, we made a ring of the required size from double-sided foil fiberglass and cut out tracks on one side of the ring for soldering LEDs and quenching SMD resistors with a nominal value of 150 ohms (a 150 ohm resistor was placed in the gap of the positive power wire of each LED ) soldered our backlight. To connect power, I soldered a mini-connector (female) to the inside of the ring.
To connect the backlight to the lens, I used a threaded round nut (not used for attaching lens glasses), which I soldered to the inside of the backlight ring (that’s why I took double-sided fiberglass).
So, the electron-optical part of the USB microscope is ready.
Now you need to think about a movable mechanism for fine-tuning the sharpness, a movable tripod, a base and a work table.
In general, all that remains is to come up with and create the mechanical part of our homemade product.
Go…
2. As a moving mechanism for fine-tuning sharpness, I decided to take an outdated mechanism for reading floppy disks (popularly called a “flop drive”).
For those who didn’t see this “miracle of technology”, it looks like this:
In short, after completely disassembling this mechanism, I took the part that was responsible for the movement of the read head, and, after mechanical modification (trimming, sawing and filing), this is what happened:
To move the head in the flop drive, a micromotor was used, which I disassembled and took only the shaft from it, attaching it back to the moving mechanism. To make it easier to rotate the shaft, I put a roller from the scroller of an old computer mouse on its end, which was inside the motor housing.
Everything turned out the way I wanted, the movement of the mechanism was smooth and precise (without backlash). The stroke of the mechanism was 17 mm, which is ideal for fine-tuning the sharpness of the microscope at any focal length of the optics.
Using two M2 bolts, I attached the electron-optical part of the USB microscope to the movable mechanism for fine-tuning the sharpness.
Creating a movable tripod did not pose any particular difficulties for me.
3. Since the times of the USSR, I had a UPA-63M enlarger lying in my barn, parts of which I decided to use. For the tripod stand, I took this ready-made rod with a mount, which was included with the enlarger. This rod is made of aluminum tube with outer ø 12 mm and inner ø 9.8 mm. To attach it to the base, I took an M10 bolt, screwed it to a depth of 20 mm (with force) into the rod, and left the rest of the thread, cutting off the bolt head.
The mount had to be slightly modified in order to connect it with the microscope parts prepared in step 2. To do this, I bent the end of the fastener (in the photo) at a right angle and drilled a ø 5.0 mm hole in the bent part.
Then everything is simple - using an M5 bolt 45 mm long through nuts, we connect the pre-assembled part with the mount and put it on the stand, securing it with a locking screw.
Now the base and table.
4. For a long time, I had a piece of translucent light brown plastic lying around. At first I thought it was plexiglass, but upon processing I realized that it was not. Well, oh well, I decided to use it for the base and table of my USB microscope.
Based on the dimensions of the previously obtained design, and the desire to make a large table for reliable fastening of boards when soldering, I cut out a rectangle measuring 250x160 mm from existing plastic, drilled a hole ø 8.5 mm in it and cut an M10 thread for attaching the rod, as well as holes for attaching the table base.
I glued the legs to the bottom of the base, which I cut out from the soles of old boots with a homemade drill.
5. The table was turned on a lathe (at my former enterprise, I, of course, do not have a lathe, although there is a 5th grade lathe) measuring 160 mm.
As a base for the table, I took a stand to level the furniture relative to the floor, it fit perfectly in size and looks presentable, besides, it was given to me by an acquaintance who had these fittings “like a fool’s shag.”
