USB Microscoop Andonstar 500x

[Endeavor]

Received today my Andonstar A1 500x digital microscope and I'm currently testing it.

There are quite a few reviews on YouTube about this microscope and most of them are positive. The reasonable sturdy metal stand is also well received. The only problem with the stand is the amount of play between the inner- & outer-tube (red arrow). On YouTube there is somebody with a solution; he machines with a lathe a whole new inner-tube with much smaller tolerances and solves the problem that way. However, on top of the outer-tube sits a screw-cap with an O-ring inside. I replaced the O-ring with a same OD but slightly thicker out of my Draper O-ring Assortment (bought once by Lidl for £5 or so) and pressed & screwed the well greased (silicon grease) cap back on. Not play whatsoever anymore .......

Another modification I like to do, as @nickelsilver suggested, is to make light on the base plate to illuminate the object from underneath (as well). For this I was thinking on a smd-led panel underneath a white transparent plastic sheet, perhaps feeding the smd's from the USB, or separately if a 12V 48smd panel is chosen. Perhaps I go even more fancy by cutting a big round hole in the base-plate and make the transparent plastic flush with the base-plate ....... Hmmm ..... that would be nice

In my case, the microscope is connected to a Macbook Pro. With OSX a program called "Photo-booth" can be used, but that isn't ideal. I found an OSX program called "Digital Viewer", which has the basis functions and seems to perform better than "Photo-booth". Here the link to "Digital Viewer" (OSX & Windows): https://plugable.com/products/usb2-micro-200x/#drivers

You can next to just looking at an object, take pictures and shoot a film;

Anyway, here is my first little test-film. For file-size reasons I had to cut it down to 10sec and save it at medium quality. I've no idea what the magnification is, but you don't need a strong microscope; perhaps 200x is fine too .....

A bit more fiddling with the focus, with the light etc, and I think for the price, it's going to be just fine

 

 

 

Edited September 27, 2018 by Endeavor

[RyMoeller]

The video quality is impressive- thanks for sharing!

[tonystime]

 I agree, the quality is great. I will have to pick one of those up also. Thanks again. 

[Endeavor]

I also found the height adjustment (by turning the outer tube of the stand) and the focus adjustment (on top of the tube-scope) easy and with the right "turn / effect ratio"; meaning that one can finely adjust both without "Oops too much, Oops too little". Another plus is the size of the scope-tube (12mm) and the clearance between scope & object. Of course the clearance depends on the magnification, but still, with a decent magnification the scope doesn't have to be right on top of the object.

The little test-film above is of a Laco 503 Ladies movement escape wheel with a 4.8mm diameter; just to give you an idea of the object-size we are looking at.

BTW; my first purchase was a cheaper plastic Chinese 1000x USB scope, which is still on its way, but after seeing Daves video, I decided to purchase the Andonstar A1 as well. So, basically I'll end up with the same set as in the video. Perhaps the cheaper plastic scope may become of some use after modifications (fx, strip the camera out of its housing) or it may becomes a kids-toy present?

Do I start to sound like a sales person ...... ??  

Edited September 28, 2018 by Endeavor

[transporter]

I just ordered this little number off of AliExpress, there’s over 80 feedback photos from buyers, and one shows the microscope at the top of the arm with a pair of tweezers on a circuit board and there is more than enough room to manipulate a hairspring etc. Well worth a punt at that price. I will do a review when it arrives ok

[Endeavor]

As said, it would indeed be nice to get some adjustable light coming from underneath the microscope, preferably neatly build in the base plate covered with a white transparent plastic to diffuse the light.

For the electronically minded people under us (and of course everybody else ), I thought I would share my modification journey.

For adjusting the LED's intensity, PWM (Pulse Width Modulation) has to be used. This means that the LED's are still powered by the full 12Volt, but the duration of the On/Off period gets altered. The LED's will still either be full on or completely off, but since the duration of On/Off is altered within a certain time period, it's our perception that the LED's burn brighter or more dim.

I had two options in mind; an Arduino circuitry or to use a 555 timer IC. The Arduino option felt a bit like shooting a fly with a bazooka, so I went for the 555 timer IC. Since the 48 smd-LED panel is 12 Volt DC and the 555 operating voltage is between 5 - 15 Volt DC, only one 12Volt power supply and one voltage is needed, no complications, nice simple & easy. I had all the parts needed at home.

This is the schematic I used. First, as a trial, build on a breadboard. The intensity is adjusted by a potentiometer.

The above schematic has just one LED for testing, however the 555 can not handle the power required for a 48 smd-LED panel. To solve this problem, an electronic switch, which can handle the higher current, has to be included. The 555 will then switch the electronic switch and the electronic switch will power the LED's directly from the 12Volt power source. The switch needed in this schematic is a NPN transistor, in this case a TIP31 is used, but any NPN-transistor with enough capacity will do.

With all assembled on the breadboard, time for testing. The LED panel lays loose on the base plate, just for getting the "idea" purpose. Of course, it has to be mounted in the base-plate right underneath the center line of the microscope.

Here at the lowest intensity;

Then at full power;

Testing the thick hard-plastic sheet at low power;

and finally at full power;

Next is getting the circuitry nicely build on a PC-board and cased in a small box. I still have to think a little about if I can combine the top LED's in the microscope with the bottom LED's and make it such the both can be independently switched & the intensity independently controlled from the same box .....

The smd-LED plate has to be build inside the base-plate, so a rectangular hole has the be cut in the aluminum. A rectangular piece of the white hard plastic will then cover the base-plate, thereby covering the LED panel.

At least that's the plan .........

Hopefully within a few days I can show you the end result ......

 

 

 

Edited September 29, 2018 by Endeavor

[transporter]

Nice one mate, electronics have never really been my thing but with you schematics you’ve made that look reasonably easy, looking forward to the finished job.

[Endeavor]

Before putting the components on a print-board, I measured the frequency of the pulses with an oscilloscope. Depending on the position of the potentiometer, with the components in the above schematic, the 555 triggered between 120 Hz and 300 Hz. To avoid any chances of flicker on a video, I changed C1 to 1nF and R2 to 680 Ω. The capacity of C1 gets lowered and by lowering the resistor R1, the capacitor will be even faster drained, causing the 555 to trigger faster. The frequency increased to a range between 1.33 kHz and 2 kHz, with a duty cycle between 3% and 99 %.

The modification of the base-plate took a little longer; the design took shape while I went along, trying to keep everything as compact as possible and near to "original"-shape when the base-light is not required .......

This meant the potentiometer to be positioned to the left of the column, a power-plug to the right of the column and the circuitry below the slightly raised base-plate. If the base-light is not required, all what needs to be done is to unplug the power supply and the microscope abse-plate is back to "original" (well, .... nearly )

12 Volt turned out to be too bright, so I ended up wit a 9V DC adapter, reducing the highest brightness and also lowering the lowest brightness to nearly nothing. Seemingly an excellent range .......

And here the circuitry tucked underneath the base-plate, all components build flat on the PCB to avoid any damage. The 4x corner studs (one adjustable to take out any "wobble") do also act as an anchor point for the 4x screws holding the white transparent plastic on top.

The PCB is by means of 4x nylon spacers slightly raised above the bottom of the base-plate, to avoid shorting out on the aluminum.

All seems to work fine. If I one day stumble over 4x countersink M3-screws, the current screws will be changed out so the top will then be flush.

Another project done .......

 

 

Edited October 4, 2018 by Endeavor

[Endeavor]

Here a little slow-motion clip (10% of normal speed) with the new back-light. The back-light in the previous clip was provided by a hand-held torch (flash-light). It doesn't take much back-light to become already "overwhelming" for the microscope. Perhaps I had it set it a bit too bright already, but for my eyes it was reasonable low.

Clear to see, even though I put a small droplet just on the impact-faces of both jewels,  that there  is still too much oil  ...... or it spreads so much and this is "normal"?

Edited October 5, 2018 by Endeavor