1st Nov, 2018 12:00

Fine Photographica & Instruments of Science & Medicine

 
  Lot 11
 

A Dall-Type Diamond Microwriter

built by Norman Groom in the 1980's from designs by Horrace Dall, complete with two micro engravings by Norman Groom. From Groom's description: 'The writer is mounted on a chipboard base about 30 x 30cms (12” X 12”) that acts as the writing tablet and carries two arms joined by a spring bearing in one corner. The precision part of the writing apparatus is mounted on a steel plate fixed to the base in the same corner. The base board itself plays no part in the writing process, but acts as a support for the arms which are held in place by ⅜” wide beryllium copper leaf springs and it also locates the writing point in an appropriate position by three quite weak and balanced coil springs, two of which are attached to the arms.' The beryllium copper strip was ‘banding’ strip used to hold English Electric ‘C’ core transformer cores together and was used extensively in the 1980’s. It was a valuable source of springy material and used extensively in the micro writer. The precision parts are mounted on a 5” X 2” x ¼” steel base plate. This base carries the bearing for the two arms, the oil-filled dashpot, the two supports for the arm that hold the cover slip and the solenoid that raises and lowers the arm, the solenoid coming from a dismantled low voltage relay. You can read the whole history here: http://www.microscopy-uk.org.uk/mag/indexmag.html?http://www.microscopy-uk.org.uk/mag/artaug09/ng-microwriter.html

Sold for £504

Result plus buyers premium


 
built by Norman Groom in the 1980's from designs by Horrace Dall, complete with two micro engravings by Norman Groom. From Groom's description: 'The writer is mounted on a chipboard base about 30 x 30cms (12” X 12”) that acts as the writing tablet and carries two arms joined by a spring bearing in one corner. The precision part of the writing apparatus is mounted on a steel plate fixed to the base in the same corner. The base board itself plays no part in the writing process, but acts as a support for the arms which are held in place by ⅜” wide beryllium copper leaf springs and it also locates the writing point in an appropriate position by three quite weak and balanced coil springs, two of which are attached to the arms.' The beryllium copper strip was ‘banding’ strip used to hold English Electric ‘C’ core transformer cores together and was used extensively in the 1980’s. It was a valuable source of springy material and used extensively in the micro writer. The precision parts are mounted on a 5” X 2” x ¼” steel base plate. This base carries the bearing for the two arms, the oil-filled dashpot, the two supports for the arm that hold the cover slip and the solenoid that raises and lowers the arm, the solenoid coming from a dismantled low voltage relay. You can read the whole history here: http://www.microscopy-uk.org.uk/mag/indexmag.html?http://www.microscopy-uk.org.uk/mag/artaug09/ng-microwriter.html
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