A condenser for a Beck

This Beck had no lacquer left although it was in good condition, not only did the owner want the microscope re-lacquered; he wanted a new condenser made so he didn’t need to use the original, separate bullseye condenser. This presented quite a challenge as there is very limited space under the microscope stage and any condenser would have to be in keeping with Beck microscopes of the period.

Construction

A 1/4″ objective was used as a condenser lens and a tiny aperture iris was obtained. The aperture iris and condenser were fixed inside a ring with centering screws (see gallery below for images) and the objective was attached via an RMS thread. The rack which carries the condenser unit was attached to another ring clamped onto the bottom of the stage (which originally carried the aperture wheel). This was convenient because the new condenser could be removed easily and the original aperture wheel reattached, no permanent alterations are required.

The original mirror was positioned in such a way that there was insufficient travel for the condenser on the rack, insufficient travel made the whole thing rather pointless so to overcome this a small sliding tube was inserted inside the tube which carried the original mirror – once again avoiding the need to make any permanent changes to the microscope. The new tube was turned down so that it had a marginally smaller outer diameter than the original one in the manner of an aerial. The new tube can be pulled down from inside the original tube when required and pushes back up to allow the microscope to be stored in the upright position.

A coat of lacquer and the new condenser was magically transformed! I think Beck would be happy.

Drawing of part of condenser

New condenser for Oberhaeuser

This Oberhauser drum microscope needed a new mirror and a new condenser. The condenser arm and holder have been made using a coping saw and hand files and special screws were made which allow the condenser arm to be repositioned whilst remaining firm. The condenser mount was made on the lathe. It just needs painting olive green now to match the rest of the microscope. It can be removed and fits neatly into the box with the rest of the microscope as the original would have done.

This microscope does not need any relacquering as the original lacquer  is still 99% intact. I have taken some pictures using the microscope – one is of a xylophyte stem and the other is of radiolarians.