New Stereo Zoom Microscope for my Electronics Lab!

January 21st, 2009 by Jeff

Soldering surface mount (SMT) components is tricky, particularly if you can’t see what you are doing due to the small scale of most SMT parts.  Since I started working with SMTs at home I have suffered with a 10x magnifier ring-light.  It works, but it’s tricky to use, mainly because the working distance is so small that getting a soldering iron on a part and keeping that part in focus are almost mutually exclusive.

The right tool for this job is a stereo microscope.  Stereo microscopes use two separate optical paths to provide you with depth perception, very helpful for working with 3-dimensional objects like printed circuit boards.  Even better is a stereo zoom microscope, where the magnification factor can be changed by turning a knob instead of swapping out lenses.

Until now I assumed that a stereo zoom microscope would be way out of my price range, at least several hundred or a thousand dollars for a very basic setup.  However, some searching on eBay showed that good deals can be had, and a used microscope with a boom stand suitable for surface mount work can be found for as little as $200-$300.  New microscopes are available for $400-$500, although there is some debate regarding the quality of low-cost imported microscopes.  Caveat emptor.

For surface mount soldering, 7-30x magnification is reasonable (that’s 10x eyepieces * a 0.7-3x objective), and a 4″ or greater working distance makes using tools under the microscope a lot easier.

I ended up buying an American Optical (AO) model 569 with an illuminator and boom stand, shown below.  Total cost was just over $200 with shipping.

Stereo Zoom Microscope

Combined with the PID controlled hotplate I just put together this is a very powerful setup for doing rework of very tiny components – I could probably work with 0402′s, maybe even 0201′s if I was careful.  Using this setup, 0805′s are easy. (and they look huge!)

The scope is very old, it was made in the late 1970s, but it has survived in extremely good condition.  Upon receiving it, I tightened some setscrews and regreased the slides and it’s as good as new, despite being over 30 years old!

American Optical Corporation

There are a few more photos of the microscope setup on flickr.

The image quality is excellent.  Here are a couple pictures of my SYBA USB-Audio Adapter taken with the microscope and my Sony DSC-V1 digital camera.  I held the camera up to one eyepiece, set it into macro mode, and snapped the shutter – these images are straight off the camera with no retouching.

Microscope images of the SYBA USB-Audio Adapter Microscope images of the SYBA USB-Audio Adapter

Click to enlarge.

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6 Responses to “New Stereo Zoom Microscope for my Electronics Lab!”

  1. Jeff says:

    I’m looking for a 0.5x secondary objective/Barlow lens for the scope. The original for this scope is an AO part# 575. If anyone knows where to find one, contact me. Thanks!

  2. kh6wz says:

    Jeff -
    Nice work! You might try looking at Surplus Shed for optical components.

    http://www.surplusshed.com/

    Cheers,
    wayne KH6WZ, friend of Tony KC6QHP

  3. Dan says:

    Try Parts Source (877) 497-6412 or Microscope and Microscope and Microtome Service Co. (800) 647-2101

  4. Jeff says:

    Hi Dan,

    I ended up buying a 0.5x secondary objective direct from Reichert, who acquired American Optical’s microscope line.

    You can still buy a lot of accessories for the Stereostar microscopes new from this webpage:

    http://www.reichertms.com/misc.php?productID=52

    Thanks for the pointers to other suppliers, this will no doubt help others looking for parts and accessories for AO scopes. At some point I’ll be looking to purchase a fiber optic illuminator, so I’ll have to give these guys a call and see what they have available.

    Thanks again,
    Jeff

  5. Kevin Townsend says:

    The 0.5x Barlow is definately a great move. I really appreciate the 8″ working distance on mine, especially if you’ve got flux spluttering around when your working with rosin-core solder. As for the import models having problems, I bought mine off ebay and couldn’t be happier with it. I’m impressed with the optical and build quality, and the only thing I’ve had to change was adding a bit of lubricant on the shafts so they don’t squeek when I move the head around. Couldn’t be happier for the price, though, and regularly recommend them to others.

    • Jeff says:

      Kevin,

      The large working distance is very helpful. The biggest downside to a large working distance is that sometimes, especially if the work is sitting on something (like my hotplate), the eyepieces can end up pretty high off the bench. I actually had to buy a better adjustable height lab chair so that I could sit up high enough to use the scope in all conditions.

      If you post the make/model # of your scope as well as where you found it on ebay, I’m sure that other visitors to the site would find that information very useful. I had a very hard time finding reviews of the import scopes when I was looking at them on eBay. That is what ultimately led me to buying an older domestic model instead. It’s great to hear that the import scopes work well, they certainly are affordable.

      Thanks for your comment!
      Jeff


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