Christmas Presents

LOMO Biolam Microscope restoration.

As you’ll have gathered, Andy got me an old LOMO Biolam microscope for Christmas. Included in the sale were an assortment of extras ‘upgrades’ (all in their own wooden boxes) to the original base unit (most I don’t think have ever been used), including a binocular head with a pair of x7 and x10 eyepieces.

Being 41 years old, it needed some TLC – the main issue being the infamous ‘Russian Tank Grease’ originally used!

You can tell it’s age as the serial number contains it’s year of manufacture – just like Takahashi do, so the ’77’ is 1977.

This instrument is still a ‘LOMO’ version, later, it was also made and marketed under the Zenith brand (we used their cameras at art college!)

Over time, this grease has solidified (think your bonfire toffee apples), so most things that were supposed to move were either very stiff or just plain stuck.

Not being very ‘DIY’, I’ve spent the last few weeks tentatively stripping it down and soaking various parts in white spirit and WD40.

 

Andy came round just after Christmas and we had ‘first light’ – this image is of a Lilly Ovary, iPhone 6 held up to the 10x eyepiece in the Binocular attachment (adds 1.5x mag) and a 20x objective (so 300x)

It was pretty tricky to achieve focus as the main (coarse focuser) was lumpy and the fine focus unit inoperable….

The microscope (thankfully) turned out to be pretty easy to take apart.

Below, the main/coarse focus unit (after spending a week in a bath of white spirit). Brushed clean with my old tooth brush and re-greased with a modern silicon alternative.

 

Image below – bottom of the ‘stage base’ – the bit where you place your slide (‘rotating stage’ also stuck!) This shows the silver-grey fine focuser mounted on the side.

Most of the microscope is cast metal and brass. The only plastic part was this strip of gearing for the condenser (the unit that focuses the light source onto the slide/specimen). The two screws though caught me out – the top being countersunk and the lower a pan-head!

The brass is ‘pre-polished’….

Below images (x2) – back of same ‘stage’ part….

…..and with gearing removed….

The biggest issue was the fine focuser. The actual unit is self contained, like the inside of a watch and ‘runs- dry’ – so no grease. Whilst it worked on it’s own, I could not get the fine focus to work once everything was reassembled…

The large metal pin (above) sits in that circular recess shown below in the middle of that brass piece. Inside the main cavity sits the fine focuser which mates to the fine focus gearing/knob just seen in the shadow right at the back.

It turned out that the brass part (with circular recess) is supposed to freely move up and down with a turn of the fine focuser…

….the movement dampened by a large spring that sits inside this circular recess on the other side (top). The spring is held in place under tension by the serial number ‘date’ cover shown earlier.

 

Once we had worked out how this works Andy………. hit it…… (carefully) with a hammer….(!!!) after judisious use of WD40. That freed the brass dovetail allowing cleaning, polishing and re-greasing…

41 years of grease (finally) removed !

Amazing what a bit of Brass can do!

Once all back together everything finally worked!

 

Andy headed off and I finished polishing up the chrome objective head and attaching the X/Y upgrade to the stage.

Later in the evening I popped over to Andy’s to try the microscope out. I still have the condenser upgrade to sort (Russian tank grease again) and then sort an LED / Halogen illuminator to replace the 15w bulb version (itself an upgrade over the supplied mirror).

 

Andy’s calibration slide – each line is 0.01mm apart.

 

The moon….?

 

ET’s hand !

 

Damian