Adding metalurgical capability to a biological microscope - part 2

Like I had previously explained, I was able to obtain from eBay (for a minimally decent cost), just the bare vertical illuminator, which didn't include any accessories. The light house was not an exception. The vertical illuminator consists the main body:

and the light house, which in the original device would be based on a halogen bulb of at least 15-20 Watts:

Adding metalurgical capability to a biological microscope - part 1

Biological microscopes among a few other things, are characterized by the fact that rely on transmitted light rather than reflected light, to produce an image of the specimen.This is adequate for most biological needs because the specimen can either be made thin enough for light to go through, or the medium and/or the specimen itself is relatively transparent to light.

However there are other applications in microscopy where it cannot be assumed that the specimen is transparent or able to be ground to a thickness small enough for light to traverse it. Some materials are opaque even at thicknesses of few microns.

The only solution in these cases is to rely on reflected light. For this to be possible, a different illumination system is required on a microscope. This type of illumination is commonly designated of epi-illumination (as opposed to trans-illumination used for biological observations). This is where a device known as vertical illuminator comes into play (picture obtained from a Olympus BHM manual):

"Wheel-bearing" Rotifer

Reconditioning a 50+ year old microscope - part 3 - LED conversion

The microscope came with what I believe it must have been the original illumination system:

• a 30 Watt / 110 Volts tungsten bulb (in this case a GE branded one):

Reconditioning a 50+ year old microscope - part 2 - XY specimen stage mechanism lubrication

Like pretty much every moving part in this microscope, the XY specimen stage mechanism also suffered from dried/sticky grease, preventing the X axis from moving at all. As such like in the previous case, the only solution was to tear it down, clean it and apply new grease and oil.

The separation of the mechanism from the stage is simple: in the bottom of the geared side (where the knobs are) this forelock is moved as shown in the picture, and by moving the Y axis to the end of its travel range, the mechanism is removed:

Reconditioning a 50+ year old microscope - part 1 - Fine Focus recovery

I thought of giving my daughter a toy microscope, to let her know of some of the things that exist but go beyond what the eyes can see. But from searching in toy stores, I could not find any product that seemed to inspire proper optical quality. Some products seemed both expensive and very basic at the same time. Some products averaged 50 Euros retail, VAT included.

So I tried to take a look at what eBay had to offer. I quickly turned my attention to real lab grade microscopes. Some were obviously very expensive, but a very wide range of offer in price/age/condition could be found. After some extensive browsing, I managed to calibrate my price expectations and define a budget. My reasoning was that given I had a initial intention of buying a 50 Euro toy microscope, now that I was looking at real lab grade microscopes, I should at least relax my budget to be double that value. I even considered going beyond that, if I found an item that I could see, decide and obtain locally (decreased risk).