May 19, 2015 at 10:55Simple quadrocopter repair (with a microscope)
Recently, a good friend of mine asked me to “see” the WLtoys v272 quadrocopter , which, as a result of an unsuccessful pirouette, attached one of the rays, after which the indication of this beam stopped working completely and the motor began to work with obvious interruptions. At the same time, if you apply a little effort "to bend" - somewhere something was restored and the engine began to work in normal mode.
Agreed "without looking." And he was very impressed with the size of the "patient":
We need to understand what is wrong with this tiny aircraft.
Visual inspection with the naked eye showed nothing (expected). But dadget.ru provided the “ portable microscope ” for testing very timely .
And then things went much more fun (and more interesting, since I had never used a microscope before for my projects in microelectronics).
One of the first photographs of the “motherboard” of the quadrocopter (to assess the capabilities of the microscope): I ’ll tell you right away that this quadrocopter is built according to a rather original scheme: the entire mechanical part (“crosspiece”) is combined with the electronic part (“printed circuit board”). Actually, the entire "skeleton" of the quadrocopter is a printed circuit board (or vice versa: the printed circuit board is a "cross"). On the one hand, it’s very convenient: no unnecessary mechanical parts, but on the other hand, if you suddenly have a problem with the printed circuit board (for example, one of the “rays” has broken off), you can throw the quadrocopter away, since it is most likely impossible to restore the printed circuit board. But who knows, suddenly, specifically in this case, it was lucky and will be able to be repaired?
He began to carefully examine the “problem” beam and immediately discovered the absence of one of the LEDs (frame size 0603) - it simply was absent, apparently, it was completely torn off when hit: The LED at the top of the “beam” was also doubtful (and not unfounded): In the photo it is seen that only the substrate is left of the LED. The crystal itself and the lens are absent.
We figured out the LEDs, but this is not the main problem. It is necessary to find the place of microcracks on the beam in the power circuit of the corresponding engine.
And again, the microscope helped. Almost immediately, this place was in doubt:
After the main malfunction was localized, the repair was already a “technical matter”: he carefully removed a part of the soldering mask with a sharp knife, tinned the “exposed” spot and soldered the thin wires. LEDs sealed in their rightful place. It was lucky that it was the red “lights” that suffered and I had them (among the “signal lights” there are still blue ones - I didn’t have such ones and would have had to disrupt the manufacturer’s plan or refuse the indication on this beam at all). I did not take pictures of the restored LEDs (no new information, I just checked the quality of their soldering). After these actions, the quadrocopter “returned to operation” ( fully functional
recovered). There will be no video with a “fly” flight - it’s too frisky, it’s almost impossible to keep track of the phone behind it (and I haven’t really mastered the control for “slow” movements suitable for shooting). Flight can be seen, for example, in this video .
Now, comments on the new instrument - a portable microscope:
The tasks that I personally feel more comfortable and easier to do with a microscope :
Safe flights to you. Take care of your "toys."
Agreed "without looking." And he was very impressed with the size of the "patient":
We need to understand what is wrong with this tiny aircraft.
They dropped the bear on the floor,
Tear off the bear's paw.
Anyway, I won’t leave him -
Because he is good.
Visual inspection with the naked eye showed nothing (expected). But dadget.ru provided the “ portable microscope ” for testing very timely .
- The microscope is equipped with a 5MP matrix, it allows you to take photos and shoot videos, it is powered by a battery (charging 5 hours, working from a fully charged battery - 4 hours).
- LED backlight (adjustable, 8 matte white LEDs with diffuser).
- Magnification from x20 (optical) to x500 (digital).
- Record photos and videos to a microSD card.
- Connect to a computer (USB cable included).
- Using a computer (or TV) as a viewfinder (computer software included, as well as an A / V cable for TV).
And then things went much more fun (and more interesting, since I had never used a microscope before for my projects in microelectronics).
All subsequent photos were taken with a microscope, were not subjected to any processing (only scaling). Each photo is a link to a full-size original image.
One of the first photographs of the “motherboard” of the quadrocopter (to assess the capabilities of the microscope): I ’ll tell you right away that this quadrocopter is built according to a rather original scheme: the entire mechanical part (“crosspiece”) is combined with the electronic part (“printed circuit board”). Actually, the entire "skeleton" of the quadrocopter is a printed circuit board (or vice versa: the printed circuit board is a "cross"). On the one hand, it’s very convenient: no unnecessary mechanical parts, but on the other hand, if you suddenly have a problem with the printed circuit board (for example, one of the “rays” has broken off), you can throw the quadrocopter away, since it is most likely impossible to restore the printed circuit board. But who knows, suddenly, specifically in this case, it was lucky and will be able to be repaired?
He began to carefully examine the “problem” beam and immediately discovered the absence of one of the LEDs (frame size 0603) - it simply was absent, apparently, it was completely torn off when hit: The LED at the top of the “beam” was also doubtful (and not unfounded): In the photo it is seen that only the substrate is left of the LED. The crystal itself and the lens are absent.
The same thing, but with the use of a digital 4x zoom and a photo of a “healthy” LED on another beam:
Remains of the LED:
“Healthy” LED:
We figured out the LEDs, but this is not the main problem. It is necessary to find the place of microcracks on the beam in the power circuit of the corresponding engine.
And again, the microscope helped. Almost immediately, this place was in doubt:
Same thing with digital zoom:
This simply cannot be identified by the eyes ...
This simply cannot be identified by the eyes ...
After the main malfunction was localized, the repair was already a “technical matter”: he carefully removed a part of the soldering mask with a sharp knife, tinned the “exposed” spot and soldered the thin wires. LEDs sealed in their rightful place. It was lucky that it was the red “lights” that suffered and I had them (among the “signal lights” there are still blue ones - I didn’t have such ones and would have had to disrupt the manufacturer’s plan or refuse the indication on this beam at all). I did not take pictures of the restored LEDs (no new information, I just checked the quality of their soldering). After these actions, the quadrocopter “returned to operation” ( fully functional
recovered). There will be no video with a “fly” flight - it’s too frisky, it’s almost impossible to keep track of the phone behind it (and I haven’t really mastered the control for “slow” movements suitable for shooting). Flight can be seen, for example, in this video .
A few more photos from the microscope:
The BK2423 chip is responsible for the radio channel (by the way, this is an analog of nRF24L01 +). Case QFN20, size 4x4mm. 2.4GHz printed antenna N-channel MOSFET in the SOT23 MTN2310N3 package (in fact, they “steer” the engines). Fragment of a ruble coin from the title photo of the post. Maximum optical zoom.
The BK2423 chip is responsible for the radio channel (by the way, this is an analog of nRF24L01 +). Case QFN20, size 4x4mm. 2.4GHz printed antenna N-channel MOSFET in the SOT23 MTN2310N3 package (in fact, they “steer” the engines). Fragment of a ruble coin from the title photo of the post. Maximum optical zoom.
Now, comments on the new instrument - a portable microscope:
- In general, I liked the device - simple, convenient, intuitive, affordable.
- The built-in color screen allows you to quickly see small details, but the screen is still small and convenient to use as a rough “viewfinder”.
- When connected to a computer (with the appropriate software, it is included in the package) - it is possible to view images directly on the computer screen (and here the size of the displayed image is limited only by the size of the monitor).
- You can connect to almost any TV (via "tulips") and use the TV screen to watch.
- The illumination system built into the microscope (8 matte white LEDs and a ring-shaped diffuser) - do their job well and greatly facilitate the work.
- It is practically impossible to use a microscope “from hand” (a very shallow depth of field, which is expected), but a heavy metal tripod in the kit solves this problem.
- You can receive both original images (color) and black and white (two options: positive and negative image - in some cases it is convenient to use these modes, especially when you need to read the marking of microcircuits made by laser engraving).
- It is possible to make a “time lapse” (automatic series of photos at set intervals) and shoot video (photos and videos are saved on a microSD card (not included in the package).
- The built-in screen does not have any characteristics (poor viewing angles, “acidic” colors, and a “broken” pixel appeared on the second day of use).
- In the description, support for the Russian language is stated, but it was not found in the microscope menu (apparently, the old firmware, but it was not possible to find a new one either). I’m not critical, but as it is.
- Rich scope of delivery: microscope, charger, rechargeable battery, case, A / V cable, USB cable, tripod, software disc, microfiber cloth.
The tasks that I personally feel more comfortable and easier to do with a microscope :
- Labeling of small components.
- Quality control of the manufacture of printed circuit boards (both at all stages of LUT, and factory).
- Monitoring the installation of SMD components.
Safe flights to you. Take care of your "toys."