From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
The gap tables for a main switch unit.
| Identifier | ExFiles\Box 168a\2\ img156 | |
| Date | 20th May 1935 guessed | |
| MAIN SWITCH UNIT GAP TABLES. Position of switch Air gap at core centre. Core to Armature stop. Copper gap (first blade to make). Carbon gap. Off .084 ±4 .090 +5 +2 .062 ±4 .025 +5 -0 Carbons just in contact. .071 ±3 .074 ±2 .040 0 Coppers just in contact. .047 -2 .045 0 0 Full on. .010 +0 -2 0 0 0 ---------- These limits must not be exceeded. Hs{Lord Ernest Hives - Chair}/Wst. | ||