Sliderules

From wikipost

Some of the slide rules I have gathered over the years:


Sun Hemmi P280

Low cost two color simplex rule. Plastic body rule with unusual blue tinted slide and two color scales. Basic student rule with trig scales, the T, ST and S scales have complimentary angles marked in red, and the scales are all self-documenting on the right hand side. Reversible slide has 3 log log scales. Unbreakable plastic cursor.

Sun Hemmi P280 (front)
Sun Hemmi P280 (back)
  • body: plastic
  • cursor: plastic
  • length: 27cm
  • Scales: 13
  • Front scale: T, K, A, [ B, CI, C, ] D, L, S, ST
  • Slide Reverse: [ LL1, LL2, LL3 ]
  • country of origin: Japan
  • year of manufacture: October 1972 [Date Code: WJ]


Sun Hemmi Teledyne 44CA-600 Versalog II

About June, 1973. The last Post Versalog II is made. The first Teledyne-Post Versalog II (new model number 44CA-600) appeared a little before then, in June 1972. For a long time, the last T-P Versalog we knew of had the date code WH (August 1972), but a recently acquired Versalog 44CA-600 example has surfaced with the date code XF, indicating June 1973 production.

Sun Hemmi Versalog II (front)
Sun Hemmi Versalog II (back)
  • body: laminated bamboo
  • cursor: metal/plastic
  • length: 27cm
  • Scales: 24
  • Front: logX, LL/1, LL/2, LL/3 [ T/T, SecT/ST, Cos/S, C ] D, LL3, LL2, LL1
  • Back Scale: LL/00, K, A, DF [ CF, CIF, CI, C ] D, R1, R2, LL0
  • country of origin: Japan
  • year of manufacture: August 1972 [Date Code: WH]


Faber Castell 52/82

Plastic body duplex rule with trademark green accent stripes on fundamental scales, and multi-line cursor. Rule face is self-documenting, with scale functions listed, as well as scale letters.

Faber-Castell 52/82 (front)
Faber-Castell 52/82 (back)
  • body: plastic
  • cursor: plastic
  • length: 10" (25.4)cm
  • Scales: 22
  • Front scales: L K A [ B BI CI C ] D LL1 LL2 LL3
  • Back scales: T T2 DF [ CF CIF S' C ] D S ST P
  • Country of origin: Germany
  • year of manufacture: August 1961 [Date Code: 861]


Faber Castell 67/87

Plastic body simplex 15cm rule with 4-line cursor, two color (red/black) scale markings, and inch side ruler, reversible slide has S, ST, and T scales. Rule is self documenting on right hand side for all scales.

Faber-Castell 67/87 (front)
Faber-Castell 67/87 (back)
  • body: plastic
  • cursor: plastic
  • length: 15cm
  • Scales: 10 + ruler
  • Front scales: K, A [ B, Ci, C ] D, L
  • Back ruler scales: S, ST, T
  • Country of origin: Germany
  • year of manufacture: April 1959 [Date Code: 459]


Pickett N1006-ES

Pickett 5" Trigonometry Duplex Rule. This is the "Eye Saver" yellow version of this rule,

Pickett N1006-ES (front)
Pickett N1006-ES (back)
  • body: aluminium
  • cursor: nylon/plastic with metal screws
  • length: 5" (12.7cm)
  • Scales: 17
  • Front scales: K, A [B, ST, T, S, C] D, DI
  • Back scales: Ln, DF [CF, CIF, CI, C] D, L
  • country of origin: USA
  • year of manufacture: 1959


Pickett N600-ES

Pickett 5" Trigonometry Duplex Rule. This is the "Eye Saver" yellow version of this rule,

Pickett N600-ES (front)
Pickett N600-ES (back)
  • body: aluminium
  • cursor: nylon/plastic with metal screws
  • length: 5" (12.7cm)
  • Scales: 19
  • Front scales: LL1, A [B, ST, T, S, C] D, DI, K
  • Back scales: LL2, DF [CF, Ln, L, CI, C] D, LL3
  • country of origin: USA
  • year of manufacture: 1962-1964

The Scales

After seeing so many slide rules it may appear confusing to see so many scales close together one one slide rule. Here is a list of the most common slide rule scales.

Letter(s) Description Applies to Colour Orientation Comments
C Single Logarithmic, 1 Decade (1-10) Multiplication, division Black left to right Usually found on slide
D Single Logarithmic, 1 Decade (1-10) Multiplication, division Black left to right Usually found on body
A Double Logarithmic, 2 Decades (1-10-100) Powers of 2 and Square Roots Black left to right Usually found on body
B Double Logarithmic, 2 Decades (1-10-100) Powers of 2 and Square Roots Black left to right Usually found on body
K Triple Logarithmic, 3 Decades (1-10-100-1000) Powers of three and Cube Roots Black left to right
L linear scale (0-1) Mantissa for Common (base 10) Logs Black left to right
S Sine scale Sines between 5.7° and 90° Black left to right
S(cos) Cosine scale Cosines between 5.7° and 90° Red right to left, combined with S scale
T Tangent scale Tangents between 5.7° and 90° Black left to right
ST Single Decade 1-10, basic scale folded at 57.3 Sines, Tangents between 0.6° and 5.7° Black left to right
Ci Inverted Single Decade 1-10 Red right to left
Di Inverted Single Decade 1-10 Red right to left
Cf Folded Single Decade 1-10 Black left to right
Df Folded Single Decade 1-10 Black left to right
P Pythagorean Scale Black left to right
LL1 Log-Log scale 1 Raising numbers to arbitrary powers Black left to right
LL2 Log-Log scale 2 Raising numbers to arbitrary powers Black left to right
LL3 Log-Log scale 3 Raising numbers to arbitrary powers Black left to right

Gauge Points

Often used numbers such as Pi, e, conversions and other ratios can be found as Gauge Points on some scales. Here is a list of common gauge points.

Symbol Value Name Applicable to Scales
g 0.01745 sin(1°) C,D
M 0.31831 1/π ratio of diameter to circumference A,B
| 0.78648 π/4 Area and Circumference of Circles C,B
// 1.182° seconds in a radian, sin(1.1818) ST
C 1.273 4/π Volume of a cylinder C
/ 1.97° minutes in a radian, sin(1.97) ST
2.718281828 Euler's Number Natural Logs, compound interest, half-life decay C
π 3.141592654 Pi ratio of circumference to diameter C
C1 3.5683 SQRT(40/π) volume of a cylinder
R 57.299 Reciprocal of Q 1 radian = 57.3 degrees Ci
g′ 3437.74 minutes in a radian Trig functions for small angles
g′′ 206264.8 seconds in a radian Trig functions for small angles