John Wall (inventor)

John Wall
Born	1932 Crayford, England)
Nationality	British
Engineering career
Significant design	Crayford focuser
Significant advance	dialyte based refracting telescopes

John Wall (born 1932 in Crayford, England) is a British design engineer, amateur astronomer, amateur telescope maker and member of the British Astronomical Association, now living Coventry England.

Biography

John Wall's aptitude for engineering won him an apprenticeship with Vickers Armstrong at the age of sixteen in the town of Crayford where he was born. He served in the army with the Royal Electrical and Mechanical Engineers in early 1950s and there became interested in telescopes and astronomy. He went on to became a design engineer at Vickers and, while working there in 1969, came up with the idea for an accurate mechanically simple eyepiece mount for amateur telescopes, the Crayford focuser. He is also known for designing dialyte based refracting telescopes, coming up with the Zerochromat retrofocally corrected refractor, including a folded 30-inch f/12 version he built in 1999.

Inventions

• 

  Drawings for the Crayford focuser

• 

  30-inch dialyte refracting telescope

References

• John Wall bio.
• When Wall met Wise

External links

• A New Refractor Concept: "The Wall Hypochromatic Refractor"
• The John Wall 30-inch refractor.
• The Crayford eyepiece mounting by John Wall - Journal of the British Astronomical Association, 81 (2), 118, February 1971
• Crayford focusers
• Crayford Eyepiece Mount
• astronomics.com's description of how the Crayford Focuser works
• Toshimi Taki's description of how to build a cheap Crayford Focuser