Picture of 10W LED fiber light source
Over the past few years I have been slowly putting together a Franken-ebay stereo microscope. The stand, microscope, and ring light all came from different vendors and were mostly selected because the price was right. Adapting the stand to the microscope turned out to be a easy job on the lathe. The ring light fit off the bat (I did measure my scope before buying so not a surprise.). But I was left without a light source. Looking on ebay for a matching source they ran from $75 to $300 depending on condition.

Eventually I decided to just build my own. The official light sources typically use a halogen bulb. These are hot and have a useful life measured in the tens or hundreds of hours. Since I was building one from scratch I decided to go with a LED light source. This should result in a light that runs cooler and longer than a halogen bulb would.

Here are some progress videos I took during development of this light source:

Early testing

Testing with the fiber ring light

Final results

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Step 1: Bill of materials and tools needed.

Picture of Bill of materials and tools needed.
Bill of material:
Since the design of the light greatly varies based on the fiber your trying to illuminate this bill of materials will be vague.
  • 1x LED (see step 2)
  • 1x Heat sink (see step 2)
  • 1x Fan (optional see step 2)
  • 1x IRF640 N-fet (optional if using a fan)
  • 1x power jack to match power supply (optional) 
  • Power supply (see driver / dimmer instructions) 
  • 1x 10W led driver / dimmer card (see instructable here
  • hookup wire
  • 6-32 screws and lock washers (various lengths see CAD data) 
  • double stick tape (I like Scotch exterior mounting tape) 
  • Kapton or electrical tape
  • thermal grease
  • Aluminum bar stock (see CAD data for sizes) 
  • heat shrink tubing
  • HVAC galvanized sheet metal

  • metal band saw or hack saw
  • Mill and lathe + supporting tooling (optional can be done on a drill press but much easier with a mill / lathe) 
  • soldering iron + solder
  • 6-32 tap and handle
  • center drill
  • #36 drill (for tapped holes) 
  • #26 drill (for clearance holes) 
  • ? drill to match outside diameter of fiber end (if not using a lathe) or boring bar (if using a lathe) 
  • end mill (exact size not critical just used to clean up the stock and cut the LED channel)
  • cutting oil 
  • calipers 
  • center punch
  • 4 jaw independent latch chuck
  • center (live or dead) 
  • dial caliper and stand 
  • test indicator and stand 
  • 2x 1-2-3 block
  • table clamping kit
  • sheet metal hole punch or metal hole saw
  • edge finder 
  • file or deburring tool 
awais mughal6 months ago

its really nice made bro

i want to make it. can i use 100 watt led for more light

wireb (author)  awais mughal6 months ago

Not with the driver I used in this one. It's maximum rating is 1A @ 25V and most 100W leds need around 3.5A. Have not had any issues with not enough light with 10W on my scope. It is really quite bright even with the fiber ring losses.

jon champ1 year ago

(y).......Really its Good Saveing

iceng1 year ago
Nice metal work and cool fan speed..  The led was well mounted and driven.
I would consider using a thermistor on the heat sink to activate the fan.

If I missed the reading it but what is the source of that light fiber
ie where did you get it and what was the cost please ?

wireb (author)  iceng1 year ago
Yea a a thermistor would have worked. I think the micro may have even had a built in thermal sensor. But was going for easy at the time since I needed it up and running for a different project I was working on.

I got the ring light off ebay. Try searching for "fiber optic ring light" usually a few up there all the time in the range of $50 to $150 for just the fiber optic assembly. I got mine for $35 after watching ebay for a few months. (The saved search feature is great. Can set it up with a search and a price range then will send you the results daily.)
iceng wireb1 year ago
Thanks voted for you 3 ways.........
iceng wireb1 year ago
Thanks voted for you 3 ways.........
I was referring to what you stated in that last video titled "...light source near final" on this page when you said it stays "ice" cool.
I don't really think you literally mean that "the heatsink stays ICE cool" do you? I get the idea, but to anyone not familiar with all of this type of work, "ice cool" might be a little confusing.