Albert Nestler, Lahr in Baden / Germany (1940) ************************************************************** VERSION (B) S C A L E S of the NESTLER » E L E K T R O « Model 37 ============================================================== Front Side Back Side ============================================================== ( 0 .. 25 cm Ruler ) V X * 1.75 (A) PS X^{2} -------------------------------------------------------------- (B) KW X^{2} S sin(0.1X) ( 30 .. 54 cm RULER IN BASE ) S&T arc(0.01X) (C) X T tan(0.1X) -------------------------------------------------------------- (D) X U X * 5.24 -------------------------------------------------------------- (LL2) exp(0.1X) = keyed to SCALE A and LEFT CURSOR-MARK (K) X^{3} R E M A R K S : ( 1° = 60' ; 1' = 60" ) ============================================================== The TRIGONOMETRIC SCALES are divided in MINUTES & SECONDS The no-named scales are marked here with their common symbols in brackets: (A),(B),(C),(D),(LL2),(K). The U-Scale is folded by ( for calculating "Revol./Minute" ) π / 60 = 0.05236 The V-Scale is folded by the "Specific Resistance of Copper" sRcu = 0.0175 Ω * mm^{2} / m The CU-Marks for "Specific Conductivity of Copper" sCcu = 57.2 m / Ω * mm^{2} = 1 / sRcu The 736-Mark for 1 PS = 0.7355 kW with "Effectiveness"-Marks for MOT (=Motor) & DYN (= Dynamo) The Mark sqrt(2g) = 4.429 for "Pressure Hight" calculations There are 3 Versions of "Model 37" in this collection: In this VERSION (B) the CURSOR IS FRAMELESS AND ----------------------------------------------- the cursor's hairlines are different and NOT SYMMETRICAL: The CENTRAL (black) and the RIGHT (red) are in the common distance (on A-Scale) AREA/DIAMETER (on X-Scale) - but the LEFT (red) is SHIFTED to the left (= 736-Mark Distance). Because the cursor's side-window was missing, it had to be h o m e - m a d e with this C A L I B R A T I O N : ----------------------------------------------------------- Set the cursor's central hairline at "2" on X-Scale, the right hairline on the SIDE-WINDOW (green) has to read "8" on K-Scale. Set cursor's left hairline at "10" on A-Scale (the central hairline now at DYN on A-Scale), the left hairline on the SIDE-WINDOW (red) has to read "e" on LL2. There is ANOTHER VERSION ( X ) on earth !!! ------------------------------------------- The NESTLER BOOKLET "Electro No.37" (p.6/7), is showing a "Model 37" with a DIFFERENT CURSOR & DIFFERENT SCALES ... In VERSION (A): The CURSOR HAIRLINES are symmetrical and in the common distance (on A-Scale) AREA/DIAMETER (on X-Scale). The LL2-Scale is UNDER the CUBIC-Scale and SHIFTED so, that CUBIC "45" is over LL2 "e" = ONLY 1 SIDE-HAIRLINE. In VERSION (C): The SR is longer, has a red 1/X and "extended" Scales. The CURSOR HAIRLINES are symmetrical again and in the common distance (on A-Scale) AREA/DIAMETER (on X-Scale). The LL2-Scale is placed OVER the CUBIC-Scale and SHIFTED, that CUBIC "52" is under LL2 "e". 2 CURSOR SIDE-Hairlines. Historical Remarks ... The slide rule came in a black cardboard case. It is made of mahogany with scales on celluloid veneer. The back side's table with constants was missing - and also the cursor's side-window was missing and had to be home-made (s.above). impressum: *************************************************************** © C.HAMANN http://public.beuth-hochschule.de/~hamann 02/06/10 |