Introduction: Soldering Microscope From SLR Zoom Lens and TV Wall Mount

Firstly I wish to thank Instructables and all the contributers helping me in the past!!

This is my first time ever to write something like this(let alone anything for the public) on the web for all to see.

I like free. I will give for nothing I like to take for nothing. If we all do it then this world would be a better place. I have done quite a few projects in the past scavenging from skips, unwanted junk and recycling the parts. This time I remembered to take photos of the process of this project.

Soldering was becoming more difficult for me and magnifying glasses weren't much help. I saw on the net that someone used a zoom lens from cctv camera and attached it to a webcam. I didn't have a cctv zoom lens. But I did have an SLR zoom lens! I liked the idea that there is alot of space between the lens and object. Space to work on. So I started this project. Besides I have lots of goodies lying around in my office and its getting more cluttered and now I got to use them up!

All the parts Are from old projects or bits lying around my office. The goal was not to buy anything but re/upcycle what I had. So I don't know the prices.

I will split this project into 3 parts:

1. Lens and viewing screen

2. Stand

3. Lighting rig

Advise: If you don't have the parts or tools then think out of the box.


Parts (If you can't find then improvise)

Lens and viewing screen

  • SLR Canon zoom lens FD 70-210mm 1:4
  • Canon Extender FD 2X-B
  • Canon rear lens cap
  • Laptop camera
  • Male to female usb 2 cable and panel mount socket
  • Delta Steel Stick
  • Asus thinkerboard s v1(or almost any SBC or even PC, MAC, Lappy)
  • Waveshare 5" screen
  • Hdmi fpv 90 degree plug +cable 150mm x2
  • Microusb fpv 90 degree + cable 150mm x2
  • USB 2 fpv straight x2
  • Risers 10mm Male Female x4
  • Lavolta 5v 3A powersupply
  • Micro usb on/off switch
  • Toy tripod
  • Camera tripod ball joint
  • Threaded rod 1/4-20 UNC 70mm
  • Butterfly bolt 1/4-20 UNC
  • Screws for risers x4
  • Alan Bolts 5mm 80mm x4
  • ScanDisk untral 16gb


  • TV wall mount
  • Lazer from a toy
  • Bicycle speedo holder
  • Self adhesive sponge strip
  • Block of wood 40mm x 140mm x 140mm
  • Hinge and screws
  • Sash window security lock and screws
  • Screws for risers x4
  • Alan Bolts 5mm 80mm x4
  • Threaded rod M8 170mm x1
  • Nut M8 x1
  • Butterfly nut M8 X
  • Self adhesive foam 10mm thick not too stiff

Lighting rig

  • 2x Strip of LEDS from bathroom mirror more the better(had 2)
  • 3x M5 70mm bolt
  • DC plug and socket
  • 3D printout

Tools (If you don't have then improvise)

  • Saw
  • circular saw
  • miter saw
  • drill and drill bits
  • screwgun(or screw drivers)
  • alan keys
  • soldering iron Solder etc
  • Super glue
  • Thread tap for screws( if you don't have try either self tapping screws.
  • calipers for measuring

  • Hot gluegun with glue
  • Soldering iron
  • 3d printer(or from a friend like I did. Thanks Simon!)
  • USB card reader for micro sd card

  • Drill and drill bits


  • Windows 10
  • BalenaEtcher
  • Virtual Keyboard
  • Guvcview
  • Thunderbird (optional)

Remember, all these things I had lying around. You might not have the same but the principle is the same. If you want to build a Soldering microscope.

Step 1: Installing OS and Software

If you are using a PC, lappy or mac just go to step 5.

I wanted to make a small digital screen for the microscope with parts I had from an old project(smart TV). An Asus Tinkerboard s that was collecting dust would be my center for the digital micropscope. One waveshare 5" capacitive touchscreen(from a portable mini computer) to keep it as minimalist as possible. I didn't want any keyboards, mice and all that spaggetti hangining out.


Tinker_Board-Debian-Stretch-V2.1.11-20200310 you can download from tinkerboard s OS dowlaod site.

Installing the softeware for the tinkerboard S direct to emmc. ExplainingComputers. But you can use an sd Card too.

To burn on SD card

1. Insert sd card in to card reader(assuming the card reader is already plugged in. Make sure they are compatible with card reader and tinkerboard os. I used ScanDisk ultra 16gd and an old external usb 2.0 card reader.

2. Download the OS you want to use with your tinkerboard s. I am using Tinker_Board-Debian-Stretch-V2.1.11-20200310 Link is above. As this is what I am using assume next steps are for this OS.

3. I am using Windows 10... So start BalenaEtcher:

  1. Click on "Select image" and select your image you downloaded
  2. Click on "Select target" that would be the location of your sd
  3. Click "flash"
  4. When ready put the fashed sd into tinkerboard and boot.

4.Boot your tinkerboard s with your new card. This is what it should look like. ExplainingComputers.

Virtual Keyboard
If you do not want a USB keyboard it is possible to install virtual keyboard via ssh(Terminal window) with command:

sudo apt-get install matchbox-keyboard

Obviously you will need to temporaraly attach a usb keyboard & mouse or you can do it via vnc from your pc or mac.

Guvcview for webcam drivers command:
sudo apt-get install guvcview

Optional setup your email client "Thunderbird" (comes as standard with tinkerboard os). I use this so I can email images to friends taken from microscope.

Step 2: Case

For the box, initially I was going to do a wooden box. A friend was kind enough to do a 3d print for me. Cool! Having used 3ds max in the past I used Autodesk Fusion 360 and churned up this box. Lots of tutorials on youtube.

In hindsite I should have put in a hole for the power supply and external usb connection for the camera. I had to manually do the holes. I also didn't want to do another printout cause I wouldn't throw it away and it would give me more clutter.

Lots of ventilation, hole in the back for tripod, 4 holes to bolt the lid to the base and large hole for the screen. I used a caliper ruler to do all the measuring, found it easier. Then transfered the measurment to Fusion.

When done exported it as fd3 file and emailed it to my kind friend Simon.

It was the first time I created a 3d print!! I was so excited when I got it that in my haste I bolted everything on. Hence some assembled pictures. The resin is a bit brittle so I didn't want to take it appart running the risk of it cracking. Lesson learnt.

Step 3: Assembing the Case and Parts

Assembing the the tinkerboard s screen and surface mount usb was pretty straight forward. For the board I attached the risers to the board. Put on some white paint on the tips of the legs and maked of where i would drill the holes. hole size was marginally smaller the the risers thread. 2.2mm so drilled 4 holes 2mm where the paint left its mark.

I had to cut a hole into one of the grills to allow for the power cable. Another hole was cut for the panel mount usb socket. The back of the case was too thick for the usb mount. So I did it sticking out like in the picture. Not very nice but its functional and its behine. No one can easliy see it. Once that was done the case was closed with the 4 bolts using an Alan key or as good as. The bolts were screwed directly into the case.

Step 4: Display Tripod

An old broken national geographic telescope tripod was used to hold the display.

I just unscrewed the broken pieces attached the Camera tripod ball joint to the threaded rod 1/4-20 UNC 70mm and Butterfly bolt 1/4-20 UNC to hold the ball joint in place.

Next I heated the center hole under the box to be soft enough to thread it with the ball joint. The hole (a smidgin over 5mm) was prefabricated on the 3d printer.


Step 5: Lens

I took out a webcam from a broken old laptop. You can see from the video above how its done. Next the case was 3d printer by my friend. Unfortunately I made the base too short. Anyway the webcam lens was unscrewed(might be used for another project) and put the webcam in the base. The lid was superglued on. If you make the base 2 mm higher then you wouldn't need to super glue it. Make sure you have the right wires connected to the usb plug! The video is in the previous step.

I used Canon Extender FD 2X-B with the lens taken out. This way I could easliy take off or change the lens.

Next a hole was drilled into the Canon rear lens cap in the center same diameter as your webcam image sensor. I used Delta steel stick to make a putty to stick the webcam case to the Canon rear lens cap. This way I was sure there wouldn't be any light coming in. Initially used bluetack to test the webcam sensor before I stuck it in the box and glued everything perminantly. Incidentaly the brown silicone is there because I drilled the hole too big for a different webcam.

Fit the Webcam on the Canon Extender FD 2X-B and the zoom lens.

That's it.

Step 6: Testing the Lens for Min Distance

Not being a photographer this bit really caught me out. Thanks to Evgeni my father inlaw who gave me a few pointers.

On one end I securely lay the Lens on a meter rule. 0mm. On the other I had a pcb. I then moved the pcb towards the lens at the same time adjusting the focus. Using the display I calibrated the min and max distance from the lens to the pcb.

By doing this I found how high the lens would need to be and if it was practical. But the distances were sensible for me.

For all the non photographers, use really bright light or on a bright day!

Step 7: Stand

Now that you know the minimum distance you can choose the stand. I had a wall mount TV bracket which looked pretty cool. It also had a heavy base to give it more stability and a working platform. There were some holes That I could do some helping hands, vice or rig. Even mount an extractor fan.

Step 8: Clamp for Stand

According to my TV wall mount I cut a bit of timber 140mm x 140mm x45mm. I did it thicker to be sure of a better grip. If you have a different mount/parts then adjust the sizes to suit yours. Using a hole cutter cut slightly less then diameter of your Canon Extender so has to have some grip. I was going to use some self-adhesive foam but didn't need to as grip was strong.

Drill a hole for the M8 threaded rod straight through. In my case 9mm.

Mark off and pre drill the holes for the hinges and lock. I did it by eye so no exact measurements.

Paint it to suit the colour of the stand. I thought I would keep it in the theme and painted it black. When dry screw the hinge and lock on like in the photos.

Screw on a nut to the end of of the threaded rod. Drill a small whole in the nut and rod. Tap the hole to match the screw.Screw the screw in to stop the nut from coming off, next put a washer on. Slide the rod through the bracket of the TV bracket, through the clamp and though in my case the other bracket. Fit the secound washer on followed by the butterfly bolt.

Step 9: Mounting and Testing

Step 10: Lazer Pointer

Looking for needle in a haystack! If there are lots of tiny components and I have to find them through a magnified lens its quite a challenge. Especially if I am not used to it. So I devised a simple but quick way to find the component in the general area by using a lazer pointer from a broken toy gun. Then accuratly pin point it via the display.

This I done using a speedo clip from a broken bicycle found in a skip. Because the clip was too big I had some self-adhisive foam strip which was stuck on the inside of the clip.

Cut and shape a plastic strip to join the laser holder and speedo clip. I mounted it on one of the crossbars. Then calibrated the lens and laser about center. Its not crucial to have it spot on as its just a helper. When I have found the component on the display I switch the laser off to work on the component.

Step 11: Lighting

Initially I was was going to build a ring light By balline. But I got hooked on fusion 360 and 3d printing. Once again my friend helped out. I built him a resitance soldering iron and he did the printout for the lighting rig.

I made the hole wide enough to take a number of lenses. From an broken Ikea light I cut the LED strips soldered and fitted inside the ring. The 3 holes were tapped for m5 screws. On the gripping end I used and gluegun to make a soft cushion so I wouldn't damage the lens case.

Power socket and plug I used from a cheap broken chordless screwdriver.

Soldered them all together and that's it.

Now ready to test it fully built!

Photo fully assembled and leds

Step 12: Results

Step 13: Other Setup and Lenses

I tried some different lenses. Canon 35mm and Canon 50mm. Notice how low i have to bring the lens down. Not so practical for soldering but Macro photography?

Step 14: Final Word

I hope this has inspired you to come up with an idea and make it. If its from junk even better. Someone asked me why not just buy a new one. Sure I could! But for starters I needed to use up my junk and make something useful/practical ;-). The main thing here is the journay not the destination. The research, thinking out of the box, customising, mind bending, adapting and common sense. It was fun and trying at times. Also discoverd 3d printing!