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Making a microscope

R

Russ

Jan 1, 1970
0
After pricing stereo microscopes and not wanting to spend $400+ And after
buying 5 or 6 little 1x,2x,4,5, magnifying lens I was wondering if there was
a way to construct a cheap stereo microscope. It doesn't have to be stereo.
It just needs to be 10-20x power and about 5 inches of clearance between the
lens and the pcb I am looking at. How would you go about putting this
together? I have a old pair of binoculars if that will help. Any ideas?
Thanks again
 
R

René

Jan 1, 1970
0
After pricing stereo microscopes and not wanting to spend $400+ And after
buying 5 or 6 little 1x,2x,4,5, magnifying lens I was wondering if there was
a way to construct a cheap stereo microscope. It doesn't have to be stereo.
It just needs to be 10-20x power and about 5 inches of clearance between the
lens and the pcb I am looking at. How would you go about putting this
together? I have a old pair of binoculars if that will help. Any ideas?
Thanks again

What works remarkably well is using a 640 x 480 quality webcam,
turning the lense to a short focus distance.
As an extra: Many webcams even have a "photo" possibility using a
button on the top (such as some thrust or logitech models).

I use this method to fins and picturize e.g. soldering errors in fine
pitch SMD stuff. The results can be e-mailed to e.g. the factory or
such.
 
D

Don Taylor

Jan 1, 1970
0
Russ said:
After pricing stereo microscopes and not wanting to spend $400+ And after
buying 5 or 6 little 1x,2x,4,5, magnifying lens I was wondering if there was
a way to construct a cheap stereo microscope. It doesn't have to be stereo.
It just needs to be 10-20x power and about 5 inches of clearance between the
lens and the pcb I am looking at. How would you go about putting this
together? I have a old pair of binoculars if that will help. Any ideas?
Thanks again

The Intel usb microscope might be an option. It has cheap plastic
lenses in it but with a little work you might be able to replace
those with reasonable quality lenses. I saw one in the Goodwill
the other day for $9. I imagine they show up on Ebay for 10x that.

I considered modifying mine to swap the lenses but never finished.
 
A

Asplanchna

Jan 1, 1970
0
For working on SMT PCB boards I generally use
an "optivisor" with a #3 lense , ~$40.00-$75.00
you can do a google on them, or call around to your local electronics
or jewelry supply place.
But if you want really cheap, make 2 of these? ;-)
http://www.funsci.com/fun3_en/ucomp1/ucomp1.htm
 
R

Russ

Jan 1, 1970
0
It says the #3 is 2.5X mag. Is that strong enough? I thought you needed at
least 10X plus. They sell stronger lens but only up to 5X. I tried a 5X
desk lens light and it wasn't strong enough. Thanks for the feedback.
 
B

Boris Mohar

Jan 1, 1970
0
It says the #3 is 2.5X mag. Is that strong enough? I thought you needed at
least 10X plus. They sell stronger lens but only up to 5X. I tried a 5X
desk lens light and it wasn't strong enough. Thanks for the feedback.


My optical stereo zoom Bausch & Lomb goes between 7 and 30. I cannot see
myself soldering anything using monocular scope. Has anybody been successful
manipulating components using a camera and a monitor?



Regards,

Boris Mohar

Got Knock? - see:
Viatrack Printed Circuit Designs (among other things) http://www.viatrack.ca
 
M

Michael A. Terrell

Jan 1, 1970
0
Boris said:
My optical stereo zoom Bausch & Lomb goes between 7 and 30. I cannot see
myself soldering anything using monocular scope. Has anybody been successful
manipulating components using a camera and a monitor?

Regards,

Boris Mohar

I am trying to build a system right now I picked up a small camcorder
with a halfway decent macro capability and a monitor that will sit on a
shelf over the bench. I am going to mount the camera and light on a
heavy microphone gooseneck so I can twist it into position. My vision
is very bad and it is the only way I can see to solder or read small
part numbers and markings. I miss having a stereo microscope on my
bench. I did all my rework under it, rather than do the work and
inspect it with a scope.
 
M

Michael A. Terrell

Jan 1, 1970
0
Don said:
The Intel usb microscope might be an option. It has cheap plastic
lenses in it but with a little work you might be able to replace
those with reasonable quality lenses. I saw one in the Goodwill
the other day for $9. I imagine they show up on Ebay for 10x that.

I considered modifying mine to swap the lenses but never finished.


I bought one new for less than $50 but it isn't much of a
microscope. The frame rate is too slow so its difficult to get a sharp
focus, and it has a horrible depth of field.
 
D

Don Taylor

Jan 1, 1970
0
I bought one new for less than $50 but it isn't much of a
microscope. The frame rate is too slow so its difficult to get a sharp
focus, and it has a horrible depth of field.

I never really considered real-time frame rate as a criteria for a
microscope. But I agree that the plastic lenses could be lots better.
There was a web page a few years ago that discussed the possibility
of replacing the lenses. Each power is provided by a separate lens
assembly that is housed inside the scope. Unlike many products, the
scope is fairly easy to open. But building a new lens assembly
might be a challenge. I studied the web page for a while but never
did go further. And I suppose automating the focus wouldn't be
out of the question. Somewhat surprisingly, the scope seems to
comply with the Twain protocols, I think, it has been a while since
I was actively playing with this. People found you could "open"
the scope with any Twain compliant application and even inspect
the properties. You weren't locked inside some incompatible SW.
So, a little stepper could drive the focus knob and just search
for maximum contrast.

I'm certainly not defending the toy. But it was surprising how
much they could deliver for the price.
 
B

Boris Mohar

Jan 1, 1970
0
I am trying to build a system right now I picked up a small camcorder
with a halfway decent macro capability and a monitor that will sit on a
shelf over the bench. I am going to mount the camera and light on a
heavy microphone gooseneck so I can twist it into position. My vision
is very bad and it is the only way I can see to solder or read small
part numbers and markings. I miss having a stereo microscope on my
bench. I did all my rework under it, rather than do the work and
inspect it with a scope.

If you can afford it, you could go for 3D video with LCD goggles and all.



Regards,

Boris Mohar

Got Knock? - see:
Viatrack Printed Circuit Designs (among other things) http://www.viatrack.ca
 
M

Michael A. Terrell

Jan 1, 1970
0
Boris said:
If you can afford it, you could go for 3D video with LCD goggles and all.

Regards,

Boris Mohar

Got Knock? - see:
Viatrack Printed Circuit Designs (among other things) http://www.viatrack.ca

Unfortunately I am 100% disabled and only get a small pension. If I
had any money to spare I would try to find a decent stereo microscope.
I have run into people who claim to have bought one at an auction for
$25, but I've never seen even a mono microscope at any auction I've gone
to. So, I'm trying to convert an 8 mm camcorder I picked up for 85
cents at a thrift store, and will use an old 9" B&W Panasonic studio
monitor.
 
M

Michael A. Terrell

Jan 1, 1970
0
Don said:
I never really considered real-time frame rate as a criteria for a
microscope. But I agree that the plastic lenses could be lots better.
There was a web page a few years ago that discussed the possibility
of replacing the lenses. Each power is provided by a separate lens
assembly that is housed inside the scope. Unlike many products, the
scope is fairly easy to open. But building a new lens assembly
might be a challenge. I studied the web page for a while but never
did go further. And I suppose automating the focus wouldn't be
out of the question. Somewhat surprisingly, the scope seems to
comply with the Twain protocols, I think, it has been a while since
I was actively playing with this. People found you could "open"
the scope with any Twain compliant application and even inspect
the properties. You weren't locked inside some incompatible SW.
So, a little stepper could drive the focus knob and just search
for maximum contrast.

I'm certainly not defending the toy. But it was surprising how
much they could deliver for the price.

The frame rate was so slow you had to adjust the focus and wait for
the next frame. I considered replacing the camera card with a standard
NTSC camera but I haven't found one to fit the available space. Its too
bad Mattel-Intel didn't make one you could hook to your TV's video
input. It would have been a better microscope if they had. Even
better, a version with both outputs.

I have several security cameras that take a "C" mount lens but I
can't find a good closeup/macro lens.
 
A

Asplanchna

Jan 1, 1970
0
If you're able to, take an old board with you to the place that sells
the optivisors & see if it works for you ( that's what I did).
Any larger magnification, and the board has to be closer, which makes
it difficult for rework with a soldering iron.
I've seen people using higher mags for rework, but it's a personal
choice.
I have used a very expensive ?x magnification stereo inspection
microscope, but that's just what it's for, inspections...I could never
do any practical rework under something like that, I guess my head
like to bobble around way too much ;-).
G'luck!
 
J

Jeff Miller

Jan 1, 1970
0
Michael said:
The frame rate was so slow you had to adjust the focus and wait for
the next frame. I considered replacing the camera card with a standard
NTSC camera but I haven't found one to fit the available space. Its too
bad Mattel-Intel didn't make one you could hook to your TV's video
input. It would have been a better microscope if they had. Even
better, a version with both outputs.

I have several security cameras that take a "C" mount lens but I
can't find a good closeup/macro lens.

I remember reading a web page that suggested (and demonstrated) that
reconfiguring the stage illumination could make a very dramatic
improvement in these. I'm sure a search on google would reveal details.
 
J

Jeff Miller

Jan 1, 1970
0
Boris said:
If you can afford it, you could go for 3D video with LCD goggles and all.



Regards,

Boris Mohar

Got Knock? - see:
Viatrack Printed Circuit Designs (among other things) http://www.viatrack.ca

A friend of mine has achieved remarkable results using common items such
as glass marbles and the lenses embedded in penlight lamps to create
microscopes. _If_ you have any experience or understsnding of optics I
would imagine _worlds_ could be done with PVC pipe and a short order out
of Edmund Scientific's optical catalog. I might suggest searching for
educational optics kits in the $30-60 range (Radio Shack used to carry
one), you'll get an assortment of lenses and some theory, perhaps enough
to build a prototype and a feel for the lens specs you'll need to order.
One of the problems you _may_ face is chromatic aberation, ie prismatic
seperation of colors: the simple kits may not go into that, and
unfortunately optics is a weak area for me so I couldn't tell you if the
solution to the problem is as simple as being sure to order corrected
lenses for your final form. Keeping proper stereo alignment across zoom,
focus, and accomodation for different (inter-occular distances of?)
users is a big part of what you pay $400 for, but if you can live with
fixed mag, fixed focal length, and accomodation for only yourself it
might be a worthwhile project. You may need to incorporate prisms to get
the angles right, I'm not sure: I don't think I've seen any stero scopes
without them. Don't rule out the possibility of finding/buying an
inexpensive stereo scope, I have an old Tasco dissection scope which I
doubt is made anymore, it's just one cut above the plastic junk they
sell at toy stores but I've used it to very great effect in aligning
scanning electron microscope filaments in their Weihnelt(sp?) housings.
I can't complain about its performance. OK maybe it's two cuts above the
plastic junk. Also if you move in the right circles you can salvage
_excellent_ and I mean _top notch_ stereo scopes from old microtomes,
eye surgery lasers, slit lamps, transmission electron microscopes: often
thrown away as bulky garbage, and people seldom stop to consider the
optics because they appear integrated. More often than not, the
integration is only skin deep and by literally loosening a thumbscrew
out pops a standard commercial scope, suitable for popping into a
dissection or boom stand. Even a very old scope from a source like this,
circa 1920's or 40's would be better or at least far more user friendly
than anything you could build.

-Jeff
 
M

Michael A. Terrell

Jan 1, 1970
0
Asplanchna said:
If you're able to, take an old board with you to the place that sells
the optivisors & see if it works for you ( that's what I did).
Any larger magnification, and the board has to be closer, which makes
it difficult for rework with a soldering iron.
I've seen people using higher mags for rework, but it's a personal
choice.
I have used a very expensive ?x magnification stereo inspection
microscope, but that's just what it's for, inspections...I could never
do any practical rework under something like that, I guess my head
like to bobble around way too much ;-).
G'luck!

This is where you need the zoom feature. Zoom in to inspect, zoom
out a little to rework, then back in for inspection. I did a lot of
soldering under a stereo microscope with it zoomed out enough to see all
the pins on an 8 pin SMD package. I used Ersin .015" solder and the
corner of .050" tip because the smaller tips didn't hold enough heat for
more than one joint without burning them up. I tested, troubleshot and
reworked boards eight hours a day for over four years this way.
 
W

Watson A.Name - \Watt Sun, the Dark Remover\

Jan 1, 1970
0
Russ said:
It says the #3 is 2.5X mag. Is that strong enough? I thought you needed at
least 10X plus. They sell stronger lens but only up to 5X. I tried a 5X
desk lens light and it wasn't strong enough. Thanks for the feedback.

One website showed a flip down loupe that makes it 2.5X, so it would
then be 3 x 2.5X or 7.5X.

You can also get a pair of clip-on loupes that fit on eyeglasses. My
dentist has a pair of those loupes that fit on his glasses and are like
telescopes. They not only magnify but 'reach out' to focus a foot or so
away, so you are not holding your hands up under your nose. Trouble is
they're $400 or something like that. They are available at some medical
supply or surgical supply stores. Another advantage is they go wherever
you go. A microscope is pretty much stuck on the bench.
 
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