Page 1 of 1

Microscope fan cooled illuminator

Posted: Sun Sep 22, 2019 7:09 pm
by Saul
Anybody had an experience with microscope fan cooled illuminator ?

Re: Microscope fan cooled illuminator

Posted: Sun Sep 22, 2019 9:46 pm
by MichaelG.
Sorry, No ... It is something I would avoid on principle.

I suppose if you have a very heavy microscope and a very small fan the effects might be undetectable
... But is it worth the risk ?

MichaelG.

Re: Microscope fan cooled illuminator

Posted: Mon Sep 23, 2019 12:26 am
by Scarodactyl
Do you mean something like an external 150w illuminator with a fiber optic light guide? Those are awesome in the right context. In the base itself...that's something you see on stereo microscope bases sometimes but I don't think it would be great at properly high magnifications.

Re: Microscope fan cooled illuminator

Posted: Mon Sep 23, 2019 4:14 am
by Saul
MichaelG. wrote:
Sun Sep 22, 2019 9:46 pm
Sorry, No ... It is something I would avoid on principle.

I suppose if you have a very heavy microscope and a very small fan the effects might be undetectable
... But is it worth the risk ?

MichaelG.
Scarodactyl wrote:
Mon Sep 23, 2019 12:26 am
Do you mean something like an external 150w illuminator with a fiber optic light guide? Those are awesome in the right context. In the base itself...that's something you see on stereo microscope bases sometimes but I don't think it would be great at properly high magnifications.
This project is finished already (no fan needed, rig's frame was as a huge heatsink):
http://www.photomacrography.net/forum/v ... 636#238636

Now I have an idea to put higher output led( 13W, 1500lm) on my LED housing viewtopic.php?f=12&t=7836
Because of the different reasons I can use little bit bigger heatsink (not sure will it be enough, still traveling from China), or use small fan - which cools perfectly, but ... vibrations (not tested yet).

Re: Microscope fan cooled illuminator

Posted: Mon Sep 23, 2019 6:54 am
by MichaelG.
Saul wrote:
Mon Sep 23, 2019 4:14 am
This project is finished already (no fan needed, rig's frame was as a huge heatsink):
http://www.photomacrography.net/forum/v ... 636#238636

Now I have an idea to put higher output led( 13W, 1500lm) on my LED housing viewtopic.php?f=12&t=7836
Because of the different reasons I can use little bit bigger heatsink (not sure will it be enough, still traveling from China), or use small fan - which cools perfectly, but ... vibrations (not tested yet).
Thanks for revealing the context ^^^

If you had asked a specific question ... I would probably have given a less general answer.

Rather busy today; but will try to post something more useful this evening.

MichaelG.

Re: Microscope fan cooled illuminator

Posted: Mon Sep 23, 2019 10:21 am
by mrsonchus
Hi, I don't suppose a simple porting of the fan's air-flow, over or through the heatsink, would be O.K.?
I have in mind a 'stand-off/alone' fan with perhaps a tube or tubes directing the airflow, with the fan isolated from the 'scope's body. The fan only needs perhaps be a very short distance from the 'scope's frame, virtually connected. I suggest this as a variation of the fiber-optic isolation of heat, only with the isolation in this case of the fan's vibration?

Sorry if that sounds daft, but it may be simple to try......

John B.

Re: Microscope fan cooled illuminator

Posted: Mon Sep 23, 2019 2:57 pm
by Scarodactyl
I wonder if one of those cool/dumb bladeless fans would work in this context.

Re: Microscope fan cooled illuminator

Posted: Mon Sep 23, 2019 3:20 pm
by jfiresto
As in a Peltier cooler?

I might try a larger, very low noise and slow turning fan. You don't need a great deal of air flow to markedly increase a heat sink's efficiency.

Re: Microscope fan cooled illuminator

Posted: Mon Sep 23, 2019 6:12 pm
by MichaelG.
MichaelG. wrote:
Mon Sep 23, 2019 6:54 am

Rather busy today; but will try to post something more useful this evening.o

MichaelG.
As promised/threatened ...

Vibration is an enemy of good photomicrography/photomacrography
Your rig looks impressive, but I have no way of knowing how stiff it is
... There may, or may not, be significant resonant frequencies
Your choice of a semi-rigid fibre-optic may cause problems, because it can input vibration to the rig.
The addition of any mechanical fan will increase the risk.

There are several ways in which you could reduce the risk of image-degrading vibration:
  • Use passive cooling [big, efficient, heat sink]
  • Use non-pumped liquid cooling [a heat pipe]
  • Provide an 'air-gap' between the light-source and the input to the fibre bundle [the optical arrangement is simple]
If you must use a fan ... Please seriously consider my third suggestion.

Happy to discuss in more detail if you wish.

MichaelG.