Through the microscope

Posts tagged ‘biolam’

Centring a lomo or meopta condenser

Scenario: You’re  trying to set up Kohler illumination on an old Lomo biolam or  Meopta microscope which has no centring mechanism on the condenser. You have the lamp centred and the field diaphragm pretty well centred and you’re ready to get the condenser centred. You pop your phase telescope in the eye tube, you look through it and horror of horrors you see something like this!

iris aperture squiffy

 

Your iris aperture (condenser aperture) is way off centre. When you enlarge the aperture part of it disappears out of view. Kohler is impossible. You’ve wiggled everything that can be wiggled and you’re about to start smacking things with a hammer in frustration. STOP! There is a solution and no microscopes have to be hit with anything.

Step 1) Remove the condenser and the stage – this shouldn’t be a problem, they come off fairly easily, especially if you remove the mirror so you can get a screw driver in more easily.

 

Removing Lomo stage

Removing Lomo stage

Step 2) Observe the condenser carrier. You will see a knurled locking screw and three tiny grub screws  – one at the front and two at the back on either side. These tiny grub screws are your centring mechanism but don’t bother trying to alter them yet, nothing will happen until you have taken off the locking ring.

Locking ring

Locking ring

 

Step 3)  Unscrew the locking ring -I used pointy ended pliers to get it started. Now you can  adjust the grub screws. Pop the condenser back while you do the adjustment. Rack the condenser almost completely up and look through the phase telescope using a low power objective. Make sure the objective is down near where the stage should be. It’s no good leaving it 20 cms up in the air.  It doesn’t matter that you have no stage and no slide to view, you’re only looking at the condenser aperture through a phase telescope.

Approximate position of grub screws shown by pink arrows

Locking ring removed. Approximate position of grub screws shown by pink arrows.

 

Step 4)  Adjust the grub screws until you see something resembling this through the phase telescope.

iris aperture central

 

Step 5)  Cry “Hallelujah!” then throw the locking ring in the bin. Well, put it somewhere safe, I have found everything to be perfectly secure without it and it’s much easier to adjust without it there.

Step 6) Put the stage back on. Good luck with that, it’s fiddly. Put the mirror back on, put on anything else you removed.

Now you can set up Kohler in the usual way.

NB. you may have to adjust the head  if that is out of whack rather than the condenser. The head has a dove tail slider which is obvious and easy to adjust. You have probably wiggled it several times during your attempts to get the condenser centred.

 

 

 

Advertisements
My Travels with Depression

A journey through therapy

The PhD Runner

Just another WordPress site

SlowRunnerGirl

running slow to get far

Running with Depression

No Stigma, Just Running

Omni Running

Running for the fun of it

Running While Fat

I'm fat. I run. And lift. And yoga. And swim. And...

Strength Running

Through the microscope

The running blog | The Guardian

Through the microscope

Women's Running

Through the microscope

Fat Guy Running

learning to run

Spock's Sister Runs

Overweight, middle aged woman running in the South West of England

Kraker Antiek

Kraker Antiek offers a collection of antique, authentic, original, rare and quality objects.

Cornish Rock Pools

For everyone who loves Cornwall's rock pools. Information about great beaches, marine wildlife and conservation.

Hulstein Antiques

"the fine art of restoring and the restoring of fine art"

Antique and Vintage Clock Collecting & Repair

Collecting, repairing and restoring antique and vintage clocks

theduderestores

reinvention. repurposing. restoration. rejuvination

%d bloggers like this: