Super Cheap Microscope With Professional Results

Hi,

Here I will brief the build of a cheap microscope with professional results.

First we need a web camera, this is a cheap one nearly Rs.350/-. Which seems to be good for such a small budget and we are using that for this project. Remove the cover of your camera and also the lens (screwed or glued to the board), we need only the bare PCB with the sensor and USB cable attached to it.

For the objective of microscope, I found a super cheap lens that has an in built focus screw and has a good build also. If you have seen cheap Red Laser module like shown below, it has a good lens system. Actually I found this while tearing down some of such damaged lasers, and it works well.
I just tried to use it as magnifying lens , it was a good choice but the aperture is small ~3mm, which is not good for viewing but more than enough for a 1/4″ sensor for imaging.

You will need to break the laser module by punching out the laser module from the brass shell, after removing the screwed-in lens and spring.

1. Web camera USB
2. RED laser
3. Copper clad (60mm x 60mm)
4. Aluminium plate (60mm x 60mm)
5. M3 screw 5mm length (4 Nos.) 15mm length (4 Nos.)
6. M3 spacer nuts 5mm long (4 Nos) 10mm long (4 Nos) M3 nuts (8 Nos.)

Make holes on copper clad according to the PCB mounting holes, I was having a board with mounting holes in 25mm square, the CMOS sensor is in the center.

DRILLING

1. Drill the copper clad with 3.5mm dia drills for the mounting holes, and at the center drill a 6mm holes (This is the diameter of our lens system salvaged from damaged LASER module).
2. Drill another four holes of 3.5mm dia for the sample holding glass sheet, preferably near the corner of the clad board.
3. Repeat the drilling on aluminum plate using the copper clad as the pattern, holes should match as you are going to assemble it together with the same screws through the respective holes.

SOLDERING

1. You need to use only the bottom of the laser lens module now for soldering. Then press it into the copper clad 6mm hole with copper of copper clad and thread of the brass shell are facing upwards. Bottom part of the both pieces should flush flat.
2. Add solder wax and solder it around or at least at 2-3 spots.
3. Screw the lens with the spring, back to the soldered brass piece.

ASSEMBLING

Sample Holder

1. Place the 4 x M3x5mm screws from non-copper side of the copper clad into the outer holes drilled for sample mount.
2. And fasten it with the 4 x M3x15mm spacer nuts on copper side .
3. Add the 4 x M3x5mm screws on the 15mm spacer and keep it loose (later we will use it adjust sample height).

Microscope

1. Put the 4 x M3x15mm screws on the copper clad holes for camera mounting.
2. Add 4 x 5mm spacer nuts on the non-copper side of it and tighten the four spacer nuts.
3. Place the web camera board sensor facing the back of the lens.
4. Add 4 x M3 nuts back of camera board and tighten it.
5. Place the whole assembly on the drilled aluminum piece and add 4 x M3 nuts on the back and tighten it up.
6. Place a Flat sheet of glass/acrylic on the four screws, where we can place specimen slides.

LENGTH CALIBRATION

1. What I have done for length calibration is, to place my smart phone with display on and facing downwards on the glass of our microscope.
2. Connected it to the USB of my computer and turned on the camera and shoot.
3. Calculated dimension of each pixel (eg: 403 ppi display has 403 pixels per inch or 15.8 pixel per mm, in other words 1 / 15.8 = 0.0633 mm pitch between two adjacent pixels ) By this method I could calibrate the entire microscope with some percent of error.
4. In my build a 640 x 480 px photo shows 934 micrometer x 667 micrometer, from this I can assume the area covered and relative size of subjects in the frame, and thus add a scale bar on each frame.

Lighting is required for objects, I used mobile torch on the sample for now. But a 5mm LED will work.

See the samples shown here and video on youtube.

Build this, just shoot and enjoy.

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Thank you so much for your visit