DIY Scienscope fiberoptic light

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Saul
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Post by Saul »

Pau wrote:Saul, take a look at the the device I've found at ebay:
http://www.ebay.com/itm/Led-light-sourc ... Sw44BYRGCu

It does just the same I proposed and you're doing: putting an adequately sized powerful LED close to the FO entrance :D
:shock: OMG ! :) My cost was ~ $35 !
Pau, thanks again for your great idea, I'm very happy with it ! More Lm, smaller footprint, closer to the entrance ! And if there is something better than Cree XHP 70 :)
Saul
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Pau
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Post by Pau »

Sold for $800 :roll:
Maybe not so expensive for medical equipment price ranges...
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Saul
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Post by Saul »

After "eggsplosion":
http://www.photomacrography.net/forum/v ... hp?t=35091
decided to go to the fanless setup with the better heat dissipation.

Temporary test setup (thanks to the Home Depot):

Image
Image

Cree XHP 70 is attached through aluminum plate to the whole stacking rig and it became a huge heatsink. Now I cannot feel any warmth on the aluminum plate closer to the led.
Saul
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Pau
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Post by Pau »

Maybe your LED was fried (yes, like an egg!) because the lack of an adequate constant current driver, take a look at Enrico's excellent explanation
http://www.photomacrography.net/forum/v ... 455#216455
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enricosavazzi
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Post by enricosavazzi »

Saul wrote:...
Cree XHP 70 is attached through aluminum plate to the whole stacking rig and it became a huge heatsink. Now I cannot feel any warmth on the aluminum plate closer to the led.
Quite OOT and with a warning about semi-serious statements, but worth mentioning nonetheless:
I don't know if it has been discussed before here, but thermal expansion is one of the phenomena that can drive a focuser for automated stacking (best for stacks with a total thickness well under 1 mm). I believe there are some commercial implementations, although I cannot remember the details.

In its simplest implementation, the subject stage is mounted on a metal rod heated e.g. by a power resistor. The length of the rod increases with its temperature. The current passing through the resistor can be increased to increase the rod temperature and length. Even simpler, start with a cold rod, feed a constant current through the resistor, and the length of the rod (especially if the rod is massive) will gradually increase as the rod gradually warms up because of its thermal capacitance. Keep shooting at the right intervals to record a stack.

Now the semi-serious part: Use the rod as heat sink for the LED (as you did with the stand column), and you get a LED-powered automated focusing stage.
--ES

Saul
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Post by Saul »

enricosavazzi wrote:... I don't know if it has been discussed before here ...
Enrico, thanks for the information!
Yes, it was discussed before, design of Kurt Wirz (Guppy):
http://www.mikroskopie-forum.de/index.php?topic=18788.0
http://www.photomacrography.net/forum/v ... ht=#141202
Now the semi-serious part: Use the rod as heat sink for the LED (as you did with the stand column), and you get a LED-powered automated focusing stage.
Ha ha, did not think about that ! Now it will add some extra nano distance to my old school stacker steps :shock: !
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Saul
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Post by Saul »

Final version:

Cree XHP-70, no fan, everything is attached to the main focus stacking setup frame, because of that heat from the LED is dissipated very well. LED is attached to aluminum base plate which is attached to the 8020 type extrusion. Takes very little space, perfectly fits between microscope base and setup's vertical column.

Image

Image
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pharamousse
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Post by pharamousse »

Saul and everyone, thank you for all this precious information.
Well, I have an Stocker & Yale Imagelite 20 working with an 150w 20V Halogen bulb. The only thing I have to keep is the fiberoptic head.

I found this CREE XHP70 White Led for motorcycle with a built in heat sink on ebay.

https://www.ebay.com/itm/CREE-Chip-XHP7 ... 0033.m2042

I'll try to put it as close as possible to the FO Head.
Question, in your last version, did you had an IR Filter ?
And, do you have the appropriate angle between your light source and the FO head ?
Our heads are round so our thoughts can change direction.

Saul
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Post by Saul »

pharamousse wrote:Question, in your last version, did you had an IR Filter ?
And, do you have the appropriate angle between your light source and the FO head ?
No IR filter. I took a risk - distance between LED & FO input is around 2mm and (theoretically) fits to the 120 degree angle. Still do not see heat impact to the FO - maybe because of the good heat dissipation . No feel of warmth at all . Of course, there is direct heat radiation to the tip of the FO guide.

Maybe I should use something like this ?
https://www.ebay.com/itm/2pcs-Diameter- ... Sw~AVYqYu2
Saul
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Pau
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Post by Pau »

Why not to mount the LED yourself?
At the linked motorcycle headlight
- the LED is placed well inside the reflector
- You have no info about the color temperature, a neutral white 4000-5000K is usually the most adequate
- You haven't a dimmer

so the only advantage is to have the heatsink already mounted
Pau

Saul
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Post by Saul »

RB, Pau,

I think, everything depends on the rest of your stacking setup design. With my very simple "Home Depot electrical department" style DIY design I fitted to my stacking rig:
- it perfectly fits between microscope base and vertical column
- has very good heat dissipation - attached to the aluminum column and horizontal support
- no fan - no vibrations
- interchangeable - I can use no name FO ring light
- easily supports FO guide weight
- uses my existing 12v power supply and dimmers

Motorcycle headlight heat sink has + & -. Old FO connector can be be attached to the metal plate, which through the headlight fins with long screws tightened to the front of the headlight. Of course, glass should be removed.

Question is how all this thing will be attached ? Separate stand ? Stacking rig ? I suspect, if it will be not attached to the another metal construction - it will be warm (at 100%) ...

BTW, I'm using cheap ebay dimmers :
https://www.ebay.com/itm/12V-8A-LED-Lig ... SwMmBVzGeI
Saul
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pharamousse
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Post by pharamousse »

Pau :
You have no info about the color temperature, a neutral white 4000-5000K is usually the most adequate
In the description section (look at the very bottom of the page)
it's written "6000K Super White" , I guess it's ok?

Anyway I ordrer one cheap XHP70 neutral white and one 100W XTE as parts for another project.

My thought was that the Motorcycle headlight heat sink has been designed (optimised and tested) to work with his reflector and his built in heatsink.
I also have 2 big PC heatsink that I could add to it and I also have a nice peace of aluminium rail that i'll use to attach the whole thing to my setup.

Saul, I bought your dimmer on ebay.

Now I just have to wait for all the parts :D
Our heads are round so our thoughts can change direction.

Saul
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Post by Saul »

pharamousse wrote: ...I bought your dimmer on ebay ...
Good power supply ? :D
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pharamousse
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Post by pharamousse »

Good power supply ? Very Happy
Yes :) 12v 8a 100w !!
Our heads are round so our thoughts can change direction.

Saul
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Post by Saul »

pharamousse wrote:...Yes :) 12v 8a 100w !!
Just make sure that under 100% it will keep same 12V :)
Mine is 12.5A - but I'm using some extra LED's connected to the same power supply
Saul
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