Zeiss Winkel GFL
Repair and LED Conversion | ||||||||||||||||||
By Dushan Grujich, on June 10th. 2014 | ||||||||||||||||||
Zeiss Winkel GFL 654-632 | ||||||||||||||||||
Microscope came equipped with a set of phase contrast objectives, a pair of 12.5X oculars, with intermediary image distance 5.0 mm designed for optical TL of 155.0 mm - mechanical TL - 160 mm, and immersion PC condenser with capability of bright field and dark field observation. All parts present but the lamp holder for the illuminator, which fits into the 'scope base. Detailed description of all the options are given in the user's manual1. It is interesting to note that objectives do not have any traces of delamination, that is otherwise quite common for Zeiss optics of the period. | ||||||||||||||||||
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Zeiss Winkel GFL base with place for the lamp holder, the three collector lenses are housed within the mirror assembly. | ||||||||||||||||||
Image also shows one part missing, which should have been held by two M2 screws, one of which was broken off with threaded part embedded into the aluminium base. It was necessary to be drilled through and re-threaded, tough job as the base is die cast aluminium and screw is steel. | ||||||||||||||||||
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The part missing was a small indexing plate which serves to index the mirror assembly correctly as well as to allow adjusting of field aperture diaphragm. Thus I made a replacement, from a 1 mm thick brass plate, I drilled through the remnant of the screw and re-tapped the hole to accept new M2 screw to hold replacement index plate, as seen on the image above. | ||||||||||||||||||
Image above shows part of the index plate protruding up to index the mirror assembly | ||||||||||||||||||
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The original, missing, lamp holder with an incandescent 15W 6V lamp | ||||||||||||||||||
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Assembled "lamp" body machined out of dur-aluminium round stock, with a LED in front and DC power receptacle on the rear | ||||||||||||||||||
Having decided not to pursue acquisition of the original lamp holder I have machined replacement which fits inside the base. I have made sure that the LED crystal is in exact plane where the tungsten filament would be. Since use of the power LED does not require frequent "lamp" replacements I have placed DC power receptacle on the rear side of the LED holder and to prevent it from accidentally coming out or from changing the postion of the LED I have drilled and tapped a hole for an M3 hex socket grub screw. | ||||||||||||||||||
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Power LED holder in its position in the base | ||||||||||||||||||
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View of the rear end of the 'scope showing the BNC connector serving as DC power receptacle |
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New hole drilled and tapped serving to fix the Power LED holder in place | ||||||||||||||||||
View of the LED from the top side of the base with the mirror assembly removed | ||||||||||||||||||
Power LED driver2 is the same one that I have used in my previous microscope LED conversion, low cost, easy to assemble and just as easy to use. |
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References: | ||||||||||||||||||
1. 40-115/III-e/USA - Zeiss Standard GFL Microscope - CARL ZEISS Oberkochen/Württ. 1962 | ||||||||||||||||||
2. Power LED Driver using LM2596S module - by Dushan Grujich Feb. 2014 | ||||||||||||||||||
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